UC-NRLF
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UNITED STATES DEPARTMENT 0F AGRICULTURE
BULLETIN No. 772
Contribution from the Bureau of Plant Industry
WM. A. TAYLOR, Chief
Washington, D. C. PROFESSIONAL PAPER
March 20, 1920
THE GENERA OF GRASSES OF THE
UNITED STATES
WITH SPECIAL REFERENCE TO THE ECONOMIC SPECIES
By
A. S. HITCHCOCK. Systematic Agrostologist
CONTENTS
Page
Scope and Plan of the Work ..... 1
Poaceae, the Grass Family ...... 5
Descriptions of the Subfamilies and Keys
to the Tribes .......... 6
Descriptions of the Tribes and Keys to
the Genera ...........
Descriptions of the Genera
1. Bamboseae, the Bamboo Tribe
2. Festuceae, the Fescue Tribe .
3. Hordeae, the Barley Tribe ..
4. Aveneae, the Oat Tribe ..... 106
5. Agrostideae, the Timothy Tribe . . 121
6. Nazieae ^he Curly-Mesquite Tribr 165
Paeg
Descriptions of the Genera Continued.
7. Chlorideae, the Grama Tribe ... 171
8. Phalarideae, the Canary-Grass Tribe 199
9: Oryzeae, the Rice Tribe 204
10. Zizanieae, the Indian-Rice Tribe . 206
11. Melinideae, the Molasses - Grass
Tribe 212
12. Paniceae, the Millet Tribe . . . .213
13. Andropogoneae, the Sorghum Tribe 252
14. Tripsaceae, the Corn Tribe .... 280
List of New Species and New Names . .288
Index 289
WASHINGTON
GOVERNMENT PRINTING OFFICE
1920
UNITED STATES DEPARTMENT OF AGRICULTURE
^^ BULLETIN No. 772
Contribution from the Bureau of Plant Industry
WM. A. TAYLOR, Chief
Washington, D. C.
PROFESSIONAL PAPER
March 20, 1920
THE GENERA OF GRASSES OF THE UNITED STATES,
WITH SPECIAL REFERENCE TO THE ECONOMIC
SPECIES.
By A. S. HITCHCOCK, Systematic Agrostologist.
CONTENTS.
Page.
Scope and plan of the work 1
Poaceae, the grass family 5
Descriptions of the subfamilies and keys to
the tribes 6
Descriptions of the tribes and keys to the
genera 8
Descriptions of the genera 22
1. Bamboscae, the bamboo tribe 22
2. Festuceae, the fescue tribe 24
3. Hordeae, the barley tribe 87
4. Aveneae, the oat tribe 106
5 Agrostideae, the timothy tribe 121
Page.
Descriptions of the genera Continued.
6. Nazieae, the curly-mesquite tribe 1G5
7. Chlorideae, the grama tribe 171
8. Phalarideae, the canary-grass tribe ... 1C9
9. Oryzeae, the rice tribe 201
10. Zizanieae, the Indian-rice tribe 206
11. Mclinideae, the molasses-grass tribe . . 212
12. Paniceae, the millet tribe 213
13. Andropogoneae, the sorghum tribe... 252
14. Tripsaceae, the corn tribe 280
List of new species and new names 288
Index ... 289
SCOPE AND PLAN OF THE WORK.
The present bulletin describes all the genera of grasses that include
species that are native, have been introduced, or are cultivated in the
United States. Under each genus are given the species that are
of economic importance, either as useful or harmful grasses. Of all
grasses the grains are of the greatest importance. Chief among other
useful grasses are those that are cultivated for meadow or pasture
and those indigenous species which furnish forage upon the native
pasture or ranges. Other important grasses are the sugar-producing
species, those used in broom or paper making, and the ornamental
species.
It is intended to give under each genus the botanical information
concerning all our grasses that are conspicuous enough to have at-
tracted the attention of agriculturists. The keys to the tribes and
97700 Bull. 77220 1
2 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
genera should enable- the user to identify the genera of all our grasses^
and the text under each genus should enable him to determine the
species of our economic grasses. Under each genus are given the
type * and the synonyms based upon American species, or the names
that have been used in an American publication.
The following generic names, of which the types have not been
found, are based on American material but are unidentifiable from
the descriptions:
Anthipsimus Raf., Journ. de Phys. 89: 105, 1819. 2 Based on A. gonopodus
Raf., " Dry hills of the Ohio."
Dactylograrama Link, Hort. Berol. 2 : 248. 1833. Based on D. cimwides Link,
described from garden specimens grown from seed from western North
America.
Flexularia Raf., Journ. de Phys. 89: 105. 1819. Based on F. comprcssa Raf.,
"Kentucky and Ohio."
The tribes have been arranged in a new sequence based on the com-
plexity of the flower structure, the most primitive being placed first
and the most highly developed last. It is impossible to arrange them
in a lineal sequence and at the same time represent their relationships,
as the phylogenetic development has not been along a single line.
The present arrangement is the closest approximation to natural re-
lationships that can be shown in sequence. The highest development
in any given tribe may be far more complex than the most primitive
example of the tribe placed above it, but the relative development of
each tribe is believed to be fairly represented by its position in the
sequence. The bamboos are placed lowest, as certain genera, such as
Arundinaria, show the least differentiation in the floral structure.
The Andropogoneae and Tripsaceae are highly specialized, as is
shown by the great diversity and complexity of the floral structures.
The tribe Oryzeae of most authors includes two groups of diverse
genera, each worthy of tribal rank. The allies of rice (Oryza) are here
1 The type species of a genus is the species or one of the species the author had chiefly
in mind when describing the genus. Most authors of to-day designate the type species,
but earlier authors usually did not. To make the application of generic names more cer-
tain, old genera are now put on a type basis ; that is, one of the original species is chosen
as the type. If, then, a genus as originally established included species belonging in two
or more genera the name of the genus goes with the type species and the species related
to it. It will be seen that the type species of a genus as here given often bears a differ-
ent generic name. (See Miegia, based on Arundinaria macrosperma, p. 22, and Panicu-
laria, based on Poa aquatica, p. 34.) This means that the genus was based on a species
previously described under a different genus. In this work the type species is given for all
generic names, whether valid or synonyms. The reasons for selecting a certain species as
the type are given in each case. Among several species, the one most familiar to the au-
thor of the genus may be selected as the type. Species described by Linnaeus in his flora
of Sweden (Flora Suecica) and in his flora of Lapland (Flora Lapponica) were familiar
to him and are often the types of his genera. (For a further discussion of types, see
Hitchcock, Generic Types with Special Reference to the Grasses of the United States, Amer.
Journ. Bot. 5 : 248-253, May, 1918 ; and Report of the Committee on Generic Types of the
Botanical Society of America, Science, n. ser. 49: 333-336, Apr. 4, 1919.)
2 The form for literature citations throughout this bulletin is in the main that used
in publications of the United States National Herbarium.
GENERA OF GRASSES OF THE UNITED STATES. 6
retained in the tribe Oryzeae, while the allies of Indian rice (Zizania)
have been segregated as the tribe Zizanieae. Several genera referred
to Oryzeae in current works on the classification of the grasses but
not represented in the United States are evidently not closely allied
to either tribe. Their disposition is deferred, pending further study.
The tribe Nazieae (Zoysieae) also is composed of diverse genera.
Hilaria and Aegopogon should be segregated from Nazia, Anthe-
phora, and their allies. They are more closely related to certain of
the Chlorideae, such as Bouteloua and Cathestecum. For the present-
they are appended to the Nazieae, as their final disposition must await
a careful comparison with several genera outside our geographical
limits.
One species of each genus is illustrated. ' A few of the larger
genera are represented by more than one illustration, especially if
the habit of the species shows considerable diversity. The chief
figure of each illustration shows the habit of the plant, and the ac-
cessory figures show the structure of the spikelets and florets. The
habit drawings are usually half natural size; the details of the
spikelet are enlarged from 2 to 20 times. The parts of the spikelet
shown are selected to indicate generic differences and are not uni-
formly of comparable parts, though there is always a figure of a
spikelet and generally of a floret. The habit drawings are by Mary
Wright Gill, and the details of the spikelet are by Agnes Chase.
There are in the United States about 1,500 species of grasses. Of
these about 60 are cultivated. Approximately 140 native species are
important forage grasses and are constituents of our stock ranges or
of wild prairie hay. Many others are occasionally eaten by stock
but are not sufficiently abundant to be included among our economic
grasses. About 60 species are w r eeds introduced from foreign coun-
tries, chiefly from Europe.
In this bulletin the word grass is used in its botanical sense, that
is, as applying only to plants of the natural family Poaceae (or
Gramineae). Many plants other than grasses are used for forage,
among such the clovers, alfalfa, vetches, peas, beans, and other
leguminous species being the most important. Sedges and rushes
resemble grasses but belong to distinct plant families. The rushes
(Juncaceae) are distinguished by having small green flowers with a
6-parted perianth. The sedges (Cyperaceae) are distinguished from
grasses by having 3-rankecl leaves. The stems are often 3-sided.
The leaves of grasses are 2-ranked and the stems are never 3-sided.
The flowers of sedges are small and greenish, like those of grasses,
but there is no bract (palea) between the flower and the rachilla.
Sedges and rushes usually inhabit wet places or marshes, . though
some of them (such as the nut-grass, Cyperus rotundus} are weeds
4 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
in cultivated soil. They are usually of little importance as forage
plants. The sedges and rushes are not included in this bulletin.
The cultivated grasses may be classified according to their use as
grains, forage grasses, sugar-producing grasses, textile grasses, soil
binders, lawn grasses, and ornamental grasses.
Grains are those grasses whose fruit or grain is used for food or
for stock feed. The common grains are wheat, corn, oats, rye, bar-
ley, rice, sorghum, and millet.
The forage grasses are those used for meadows, pastures', soiling,
and silage.
Meadow grasses are those cut for hay. The chief meadow grasses
of the United States are (1) in the cool humid region, timothy, red-
top, orchard grass, and meadow fescue; (2) in the warm humid
region, Bermuda grass, Johnson grass, and (in Florida) Natal grass:
(3) in the dry area east of the Great Plains, millet and sorghum
(including its varieties, such as kafir and Sudan grass) ; (4) in
the northern part of the Great Plains, brome-grass ; (5) on the Pa-
cific coast, wheat, oats, and barley for the production of grain hay.
Wild hay is chiefly from three sources: (1) Prairie hay from the
region lying just east of the Great Plains, including various native
species such as big bluestem (Andropogon furcatm}* little bluestem
(A. scoparius), Indian grass (Sorghastrum nutans), and switch-
grass (Panicum virgatum) ; (2) fresh marsh hay from the region be-
tween the Dakotas and Michigan, including chiefly bluejoint (Cala-
magrostis canadensis) , reed canary grass (Phalams ammdinacea) ,
and slough-grass (Beckmannia erucaeformis) ; and (3) salt marsh
hay used mostly for bedding and for packing, including usually salt-
marsh grass (Spartina patens) and black-grass (a kind of rush,
Juncus gerardi).
Pasture grasses are those that furnish forage to grazing animals.
The two most important cultivated pasture grasses of the United
States are bluegrass in the Northern States and Bermuda grass in
the South. The meadow grasses are also used for pasture, and in
the Gulf States carpet grass is of some importance.
The wild grasses used for grazing are commonly called range
grasses. The most important are (1) on the Great Plains, buffalo
grass, curly mesquite, and grama (Bouteloua grac'dis and B. hirsuta) ;
(2) in the Southwest, several species of grama (Bouteloua), Hilaria,
and Sporobolus airoides; (3) in the mountain regions, pine-grass,
blue bunch-grass, and mountain bunch-grass (in Oregon) ; Arizona
fescue (in northern Arizona) ; and the wheat-grasses (in the Rocky
Mountains).
Soiling grasses, those cut and fed green, include the common small
grains, corn, and the sorghums, and (locally in the South) pearl
millet and teosinte.
GENERA OF GRASSES OF THE UNITED STATES. 5
Any forage grass may be preserved in a silo, but corn is the one
most commonly used for this purpose.
The most important lawn grasses are (1) in the North, bluegrass,
Rhode Island bent, and creeping bent; (2) in the South, Bermuda
grass, carpet grass, and St. Augustine grass.
The ornamental grasses include the reeds, such as pampas grass
and eulalia ; border grasses, such as fountain grass and blue fescue ;
and variegated grasses, such as ribbon grass.
Soil-binding grasses are species having vigorous rhizomes which
hold sand or other loose soil and prevent erosion by water or wind.
Banks are secured against water erosion by a covering of redtop or
Bermuda grass. The most important sand binder in use in this coun-
try is beach-grass (AimnophUa arenaria). This is planted upon
sand dunes to prevent wind erosion.
The two sugar-producing grasses are sugar cane and the saccha-
rine varieties of sorghum. No textile grasses are cultivated in the
United States. The esparto grasses (Spartina tenacissima and
Lyyeum spartum) of Spain and Algeria furnish fiber for the
manufacture of paper and cordage.
All these grasses are mentioned in the text under the proper genus.
(See index.)
POACEAE, THE GRASS FAMILY.
Flowers perfect (rarely unisexual), small, with no distinct peri-
anth, arranged in spikelets consisting of a shortened axis (rachilla]
and 2 to many 2-ranked bracts, the lowest two being empty (the
glumes, rarely one or both .of these obsolete), the one or more succeed-
ing ones (lemmas] bearing in their axils a single flower, and, between
the flower and the rachilla, a second 2-nerved bract (the palea), the
lemma, palea, and flower together constituting the floret; stamens 1
to 6, usually 3, -with very delicate filaments and 2-celled anthers;
pistil 1, with a 1-celled 1-ovuled ovary, 2 (rarely 1 or 3) styles, and
usually plumose stigmas; fruit a caryopsis with starchy endosperm
and a small embryo at the base on the side opposite the hilum.
Herbs, or rarely woody plants, with usually hollow stems (culms)
closed at the nodes, and 2-ranked parallel-veined leaves^ these con-
sisting of 2 parts, the sheath, enveloping the culm, its margins over-
lapping or sometimes grown together, and the Made, usually flat;
between the two on the inside, a membranaceous hyaline or hairy
appendage (the liguZe) .
The spikelets are almost always aggregated in spikes or panicles
at the ends of the main culms or branches. The perianth is usually
represented by 2 (rarely 3) small hyaline scales (the lodicules) at
the base of the flower inside the lemma and palea. The grain or
6 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
cjiryopsis (the single seed and the adherent pericarp) may be free,
as in wheat, or permanently inclosed in the lemma and palea. as in
the oat. Rarely the seed is free from the pericarp, as in species of
Sporobolus and Eleusine. The culms of bamboos are woody, as are
also those of a few genera, such as Olyra and Lasiacis, belonging to
other tribes. The culms are solid in our species of the tribes Trip-
saceae and Andropogoneae. The margins of the sheaths are grown
together in species of Bromus, Danthonia. Festuca, Melica, Panicu-
laria, and other genera.
The parts of the spikelet may be modified in various ways. The
first glume, and more rarely also the second, may be wanting. The
lemmas may contain no flower, or even no palea, or may be reduced
or rudimentary. Rarely, as in species of Agrostis and Andropogon,
the palea is obsolete.
Most of the genera of grasses fall naturally into one of the two
series or subfamilies. The remaining few are rather arbitrarily as-
signed to one or the .other series. In the same manner, most of the
genera may be assembled into distinct and w T ell-marked tribes, but
several are not closely allied to the other genera in the tribe to which
the} 7 are assigned but are so placed for convenience in classification.
DESCRIPTIONS OF THE SUBFAMILIES AND KEYS TO THE TRIBES.
SUBFAMILY 1, POATAE.
Spikelets 1 to many flowered, the reduced florets, if any. above the
perfect florets (except in Phalarideae ; sterile lemmas below as well
as above in Campulosus, TJniola, and Blepharidachne) ; articulation
usually above the glumes; spikelets usually more or less laterally
compressed.
Key to the t riles of Poatae.
riiints woody, the culms perennial; spikelets several-flowered.
1. Bamboseae (p. 22).
Plants herbaceous, the culms annual.
Spikelets with 2 staminate, neuter, or rudimentary lemmas unlike
and below the fertile lemma; no sterile or rudimentary rtoivts
above 8. Phalarideae (p. 199).
Spikelets without sterile lemmas below the perfect floret (or these
rarely present and like the fertile -ones, a dissimilar pair below
and a rudimentary floret above in Blepharidachue).
Spikelets unisexual, articulate below the glumes, 1-flowered,
terete or nearly so 10. Zizanieae (p. 200).
Spikelets perfect (rarely unisexual but then not as above), usu-
ally articulate above the glumes.
Spikelets articulate below the glumes, 1-flowered, very flat,
the lemma and palea about equal, both keeled; glumes
small or wanting 9. Oryzeae (p. 204),
GENERA OF GRASSES OF THE UNITED STATES. 7
Spikelets articulate above the glumes (rarely below, but the
glumes, at least one, well developed).
Spikelets 1-flowered in groups (short spikes) of 2 to 5
(single in Osterdamia), the groups racemose along
a main axis, falling entire ; lemma and palea thin-
ner than the glumes 6. Nazieae (p. 165).
Spikelets not as above.
Spikelets sessile on a usually continuous rachis
(short-pedicellate in Leptochloa; the rachis
disarticulating in Monerina, Phpliurus, Hor-
deum, Sitanion, and a few species of allied
genera).
Spikelets on opposite sides of the rachis; spike
terminal, single /. 3. Hordeae (p. 87).
Spikelets on one side of the rachis ; spikes usu-
ally more than 1, digitate or racemose.
7. Chlorideae (p. 171).
Spikelets pedicellate in open or contracted, some-
times spikelike, panicles (sessile and distant
in Eragrostis sessilispica) .
Spikelets 1-flowered 5. Agrostideae (p. 121).
Spikelets 2 to many flowered.
Glumes as long as the lowest floret, usually
as long as the spikelet; lemmas
awned from the back (spikelets awn-
less in Koeleria and Sphenopholis).
4. Aveneae (p. 106).
Glumes shorter than the first floret (except
in Dissanthelium with ,long rachilla
joints) ; lemmas awnless or awned
from the tip or from a bifid apex.
2. Festuceae (p. 24).
SUBFAMILY 2, PANICATAE.
Spikelets with one perfect terminal floret (disregarding those of
.ne few monoecious genera and the st animate and neuter spikelets)
and a sterile or staminate floret below, usually represented by a sterile
lemma only, one glume sometimes (rarely both glumes) wanting;
articulation below the spikelets, either in the pedicel, in the rachis, or
at the base of a cluster of spikelets, the spikelets falling entire, singly,
in groups, or together with joints of the rachis; spikelets, or at least
the fruits, more or less dorsally compressed.
Key to the tribes of Pamcatae.
Glumes membra naceous, the sterile lemma like the glumes in texture.
Fertile lemma and palea thinner than the glumes; sterile lemma
awned from the notched summit 11. Melinideae (p. 212).
Fertile lemma and palea indurate or at least firmer than the glumes.
12. Paniceae (p. 213).
Glumes indurate ; fertile lemma and palea hyaline or membranaceous, the
sterile lemma (when present) like the fertile one in texture.
Spikelets unisexual, the pistillate below, the staminate above, on the
same inflorescence or in separate inflorescences.
14. Tripsaceae (p. 280).
8 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Spikelets in pairs, one sessile and perfect, the other pedicellate and
usually staminate or neuter (the pedicellate one sometimes
obsolete, rarely both pedicellate) ; lemmas hyaline.
13. Andropogoneae (p. 1252).
DESCRIPTIONS OF THE TRIBES AND KEYS TO THE GENERA.
TRIBE 1, BAMBOSEAE.
The tribe which includes the bamboos is for the most part confined
to the Tropics and Subtropics. One genus extends into the southern
United States. The bamboos have woody jointed, usually holloAV
culms either erect or vinelike. Some of the larger kinds are as much
as a foot in diameter and, 100 feet in height. The common economic
species of the Tropics, such as Bambos vulgaris Schrad. (Banibos
bambos (L.) Wight), because of the large hollow culms with hard
partitions at the nodes found in most large species, can be
used for a great variety of purposes. Many kinds of bamboos
are cultivated for ornament in the warmer parts of the United States,
especially in Florida and California. Arundinaria japonica Sieb.
and Zucc. with several-flowered spikelets, and a few species of Phyl-
lostachys, are hardy as far north as Washington. They form dense
masses of shoots, usually 8 to 20 feet high. Phyllost achys does not
usually flower in this country, but the plants can be distinguished by
the internodes which are flattened on one side. Bambusa is a modi-
fied spelling of the original Bambos.
TRIBE 2, FESTUCEAE.
Spikelets more than 1-flowered, usually several-flowered, in open,
narrow, or sometimes spikelike panicles; lemmas awnless or awned
from the tip, rarely from between the teeth of a bifid apex ; rachilla
usually disarticulating above the glumes and between the florets.
A large and important tribe, mainly inhabitants of the cooler
regions. The lemma is divided into several awns in Pappophorum
and its allies, is 'deeply 2-lobed In Triplasis and in a few species of
Triodia, 3-lobed in Blepharidachne, several-toothed in Orcuttia, and
slightly 2 -toothed in Bromus and a few other genera, the awn, when
single, arising from between the teeth. The paleas are persistent
upon the continuous rachilla in most species of Eragrostis. Sclero-
pogon, Monanthochloe, Distichlis, and a few species of Poa and
Eragrostis are dioecious. Gynerium, Cortaderia, Arundo, and Phrag-
mites are tall reeds. In Blepharidachne there is a pair of sterile
florets at the base of the single fertile floret, and a rudiment above.
In some species of Melica there is, above the fertile florets, a club-
shaped rudiment consisting of one or more sterile lemmas. In Uniola
there arc one to four sterile lemmas below the fertile ones. In Melica
imperfecta and M. torreyana there may be but one perfect floret.
GENERA OF GRASSES OF THE UNITED STATES.
Key to the genera of Festuceae.
la. Plants dioecious, the sexes very dissimilar, the pistillate lemmas with
3 long twisted divergent awns, the staminate lemma awnless
or mucronate 30. SCLEROPOGON.
Ib. Plants with perfect flowers, or, if dioecious, the sexes not dissimilar
in appearance 2
2a. Lemmas divided at the summit into 5 to several awns or awn-
like lobes 3
,>;i. Awnlike lobes 5 ; inflorescence a simple erect raceme. 29. ORCUTTIA.
3b. Awns 9 or more 4
4a. Awns unmixed with awned teeth ; all the florets falling
attached, their awns forming a pappuslike crown, only
the lowest floret fertile ; panicles narrow. 32. PAPPOPHOBUM.
4b. Awns mixed with awned teeth; florets not falling at-
tached, the rachilla disarticulating between them;
panicles somewhat open 31. COTTEA.
2b. Lemmas awnless, with a single awn, or, if 3, the lateral awns
minute 5
5a. Tall stout reeds with large plumelike panicles; lemmas or
rnchilla with long silky hairs as long as the lemmas G
Ga. Lemmas hairy; rachilla naked 19. ARUNDO.
Gb. Lemmas naked; rachilla hairy 20. PHRAGMITES.
5b. Low or rather tall grasses, rarely over 5 feet tall 7
7a. Plants dioecious, perennial; lemmas glabrous; grasses
of salt or alkaline soils 8
8a. Plants low and creeping; spikelets obscure, scarcely
differentiated from the short crowded rigid
leaves 16. MONANTHOCHLOE.
Sb. Plants erect from creeping rhizomes; spikelets in a
narrow simple exserted panicle 17. DTSTICHLIS.
7b. Plants not dioecious (except in a few species of Poa with
villous lemmas and in an annual species of Eragrostis) _ 9
9a. Spikelets of two forms, sterile and fertile intermixed ;
panicle dense, somewhat one-sided 10
lOa. Fertile spikelets 2 or 3 flowered ; sterile spike-
lets with numerous rigid awn-tipped glumes;
panicle dense and spikelike 22. CYNOSTJRTTS.
lOb. Fertile spikelets with 1 perfect floret, long-
awned ; sterile spikelets with many obtuse
glumes ; panicle branchlets short, nodding.
23. ACHYRODES.
9b. Spikelets all alike in the same inflorescence 11
lla. Lemmas 3-nerved, the nerves prominent, often
hairy 12
12a. Inflorescence a few-flowered head or capi-
tate panicle overtopped by the leaves or
partly concealed in them ; lemmas toothed
or cleft ; low plants of the arid regions, _ 13
13a. Inflorescence hidden among the sharp-
pointed leaves, not woolly; plants
annual (Chlorideae) 97. MUNROA.
13b. Inflorescence a capitate woolly panicle,
not concealed ; plants perennial 14
10 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Key to the genera of Festiweae Continued.
14a. Lemmas cleft either side of the midnerve to near the
base, the lower two sterile, the third floret fertile, the
fourth reduced to a 3-awned rudiment- 28. BLEPHABIDACHNE.
14b. Lemma 2-lobed but not deeply cleft, all fertile but the
uppermost 26. TEIODIA.
12b. Inflorescence an exserted open or spikelike panicle 15
15a. Lemmas pubescent on the nerves or callus (except in Tri-
*odia albescens), the midnerve usually exserted as an awn
or mucro 16
16a. Nerves glabrous; callus densely hairy; lemmas firm;
panicle large, diffuse 15. REDFIELDIA.
16b. Nerves hairy at least below, the lateral ones often
conspicuously so 17
17a. Palea long-ciliate on the upper half 27. TRIPLASIS.
17b. Palea sometimes villous but not lorig-ciliate on the
upper half; perennials 26. TEIODIA.
15b. Lemmas not pubescent on the nerves nor callus (the inter-
nerves sometimes pubescent), awnless IS
18a. Glumes longer than the lemmas ; lateral nerves of lemma
marginal, the internerves pubescent 14. DISSANTHELIUM.
ISb. Glumes shorter than the lemmas; lateral nerves not
marginal, the internerves glabrous 19
19a. Lemmas chartaceous; grain large and beaked, at
maturity forcing the lemma and palea open_ 13. DIAEINA.
19b. Lemmas membranaceous ; if firm, the grain neither
large nor beaked 20
20a. Spikelets subterete; palea longer than the
lemma, bowed out below 12. MOLINIA.
20b. Spikelets compressed ; palea not longer than the
lemma, not bowed out below 21
21a. Lemmas truncate ; spikelets 2-flowered.
11. CATABBOSA.
21b. Lemmas acute or acuminate; spikelets 3
to many flowered ; rachilla continuous,
the paleas usually persistent after the
fall of the lemmas 10. EEAGEOSTIS.
111). Lemmas 5 to many nerved, the nerves sometimes obscure 22
22a. Spikelets with 1 to 4 empty lemmas below the fertile florets;
nerves obscure; lemmas firm 18. UNIOLA.
22b. Spikelets with no empty lemmas below the fertile florets ; nerves
usually prominent; lemmas membranaceous (firm in a few
species of Bromus and Festuca) 23
23a. Lemmas flabellate; glumes wanting; inflorescence dense,
cylindric; low annual 25. ANTHOCHLOA.
23b. Lemmas not flabellate; glumes present; inflorescence not
cylindric 24
24a. Palea winged on the lower half of the keels; spikelets
linear, in a loose raceme 5. PLEUEOPOGON.
24b. Palea not winged on the lower half of the keels; in-
florescence mostly paniculate 25
25a. Lemmas as broad as long, the margins outspread;
florets closely imbricate, horizontally spreading- 9. BBIZA.
25b. Lemmas longer than broad, the margins clasping
the palea ; florets not horizontally spreading 26
GENEKA OF GRASSES OF THE UNITED STATES. 11
Key to the genera of Festuceae Continued.
2Ga. Callus of florets bearded ; lemmas erose at the summit 7. FLUMINEA.
26b. Callus not bearded (lemmas cobwebby at base in Poa) ; lemmas not
erose (slightly in Puccinellia) 27
27a. Lemmas keeled on the back (somewhat rounded in Poa scabrella
and its allies) 28
28a. Spikelets strongly compressed, crowded in one-sided clusters
at the ends of the stiff, naked panicle branches 21. DACTYLIS.
28b. Spikelets not strongly compressed, not crowded in one-sided
clusters 29
29a. Lemmas awned from a minutely bifid apex (awnless or
nearly so in Bromus unioloides and B. brizaeformis) ;
spikelets large 2. BROMUS.
20b. Lemmas awnless ; spikelets small 8. POA. '
27b. Lemmas rounded on the back (slightly keeled toward the summit
in Festuca and Bromus) 30
30a. Glumes papery ; lemmas firm, strongly nerved, scarious-mar-
gined ; upper florets sterile, often reduced to a club-shaped
rudiment infolded by the broad upper lemmas; spikelets
tawny or purplish, usually not green 24. MELICA.
30b. Glumes not papery ; upper florets not unlike the others 31
31a. Nerves of the lemma parallel, not converging at the sum-
mit or but slightly so ; lemmas awnless mostly obtuse. 32
32a. Nerves prominent ; plants usually rather tall, grow-
ing in woods or fresh-water marshes 4. PANICULARIA.
32b. Nerves faint ; plants low, growing in saline soil.
6. PUCCINELLIA.
31b. Nerves of the lemma converging at the smmmit ; lemmas
awned or pointed (upper florets only minutely awn-
tipped in Bromus brizaeformis) 33
33a. Lemmas entire, awned from the tip or pointed
(minutely toothed in Festuca elmeri and F.
gigantea} 3. FESTUCA.
33b. Lemmas awned or awn-tipped from a minutely bifid
apex 2. BROMTJS.
TRIBE 3, HORDEAE.
Spikelets 1 to several flowered, sessile on opposite sides of a jointed
or continuous axis forming symmetrical (not one-sided) spikes.
This small but important tribe, found in the temperate regions of
both hemispheres, includes our most important cereals, wheat, barley,
and rye. The rachis is flattened or concave next to the spikelets, or
in some genera is thickened and hollowed out, the spikelets being
more or less inclosed in the hollows. In Triticum and its allies there
is one spikelet at each node of the rachis; in Hordeum and its allies
there are two or three at each node. In Lolium and its allies the
spikelets are placed edgewise to the rachis, and the first or inner
glume is suppressed except in the terminal spikelet. The rachilla of
the spikelet disarticulates at maturity in several genera. In some
species of Elymus and especially in Sitanion the glumes are very
12- BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
slender, extending into long awns, in the latter genus sometimes
divided into several slender bristles. In this tribe the blades of the
leaves bear on each side at the base a small appendage or auricle.
Key to the genera of Hordeae.
la. Spikelets solitary at each node of the rachis (rarely 2 in species of
Agropyron, but never throughout) 2
2a. Spikelets 1-flowered, sunken in hollows in the rachis; spikes
slender, cylindric; low annuals 3
3a. Lemmas awned ; florets lateral to the rachis 36. SCRIBNKRIA.
3b. Lemmas awnless ; florets dorsiventral to the rachis 4
4a. First glume wanting 42. LEPTUBTJS.
4b. First glume present, the pair standing in front of the
spikelet 43. PIIOLIURUS.
2b. Spikelets 2 to several flowered, not sunken in the rachis 5
5a. Spikelets placed edgewise to the rachis ; first glume wanting
except in the terminal spikelet 41. LOT.ITJM. "
5b. Spikelets placed flatwise to the rachis G
6a. Plants perennial i 33. AGROPYRON.
6b. Plants annual 7
7a. Glumes ovate, 3-nerved 34. TRTTICUM.
7b. Glumes subulate, 1-nerved 3.1. SKCAI.K. v
Ib. Spikelets more than 1 at each node of the rachis 8
8a. Spikelets 3 at each node of the rachis, 1-flowered, the lateral
pair pediceled, usually reduced to awns 40. HORDEUM. *
8b. Spikelets 2 at each node of the rachis, alike, 2 to 6 flowered 9
9a. Glumes wanting or reduced to 2 short bristles ; spikelets hor-
izontally spreading at maturity ; spikes very loose 39. HYSTRIX.
9b. Glumes usually equaling the florets; spikelets appressed or
ascending 10
lOa. Rachis continuous (rarely tardily disarticulating) ;
glumes broad or narrow, entire 37. ELYMTJS.
lOb. Rachis disarticulating at maturity; glumos subulate,
extending into long awns, these and the awns of the
lemmas making the spike very bristly 38. STTAXIOX. *
Tin in: 4, AVKXKAE.
Spikelets 2 to several flowered in open or contracted panicles, or
rarely in racemes (solitary in Danthonia unispicata) ; glumes usually
as long as or longer than the first lemma, commonly longer than all
the florets; lemmas usually awned from the back or from between
the teeth of a bifid apex, the awn bent, often twisted, the callus and
rachilla joints usually villous.
A rather small tribe widely distributed in both warm and cool
regions. In our genera the rachilla is prolonged beyond the upper
floret as a slender stipe (except in Aspris). The lemma is awnless
or nearly so in Sphenopholis and in our species of Koeleria. These
genera are placed in this tribe because they appear to be closely
allied to Trisetum with which they agree in having oblanceolate
glumes about as long as the first floret.
GENERA OF GRASSES OF THE UNITED STATES. 13
Key to the genera of Avcncae.
la. Spikelets awnless or the upper lemma mucronate (rarely short-awned
in Splienopliolis) 2
2a. Articulation bolow the glumes ; glumes distinctly different in
shape, the second widened above 4G. SIMIKMOPIIOLIS.
2b. Articulation above the glumes; glumes similar in shape, 44. KOKLKKIA.
Ib. Spikelets awned (awnless in Trisetum wolfii) 3
3u. Florets 2, one perfect, the other staminate 4
4a. Lower floret staminate, the awn twisted, geniculate, ex-
sorted 48. ARRHENATHERUM.
4b. Lower floret perfect, awnless; awn of upper floret hooked.
51. NOTHOLCUS.
3b. Florets 2 or more, all alike except the reduced upper ones 5
5a. Awn arising from between the teeth of a bifid apex, flat-
tened, twisted ; inflorescence a simple panicle or reduced
to a raceme or even to a single spikelet 52. DANTHONIA.
5b. Awn dorsal, not flattened ; lemma often bifid at apex G
6a. Spikelets large, the glumes over 1 cm. long 47. AVENA.*-*'
6b. Spikelets less than 1 cm. long 7
7a. Lemmas keeled, bidentate; awn arising from above
the middle 45. TRISETUM.
7b. Lemmas convex ; awn from below the middle 8
8a. Rachilla prolonged behind the upper floret; lem-
mas truncate and erose-dentate at summit 49. AIRA.
8b. Rachilla not prolonged ; lemmas tapering into 2
slender teeth 50. ASPRIS. ,
TRIBE 5, AGROSTIDEAE.
Spikelets 1-flowered, usually perfect, arranged in open, contracted,
or spikelike panicles, but not in true spikes nor in one-sided racemes.
A large and important tribe, inhabiting more especially the tem-
perate and cool regions. The articulation of the rachilla is usualty
above the glumes, the mature floret falling from the persistent
glumes, but in a few genera the articulation is below the glumes, the
mature spikelet falling entire (Alopecurus, Cinna, Polypogon,
Lycurus, and Limnodea). The palea is small or wanting in some
species of Agrostis. In a few genera the rachilla is prolonged
behind the palea as a minute bristle, or sometimes as a more pro-
nounced villous stipe (Brachyelytrum, Limnodea, Cinna, three species
of Agrostis, Gastridium, Calamagrostis, Ammophila, and Lagurus).
In some genera the rachilla joint between the glumes and the lemma
is slightly elongated, forming a hard stipe which remains attached
to the mature fruit as a pointed callus. The callus is well marked
in Stipa (especially in S. spartea and its allies) and in Aristida, the
mature lemma being terete, indurate, and convolute, the palea wholly
inclosed. In many genera the lemma is awned either from the tip
or from the back, the awn being trifid in Aristida.
14 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Key to the genera of Agrostideae.
la. Glumes wanting; a low annual 58. COLEANTHTTS.
Ib. Glumes present (the first obsolete in ^fuJllcnJ)crgia scJircbcri and
sometimes in Brachyelytrum and Phippsia) 2
2a. Rachilla articulate below the glumes, these falling with the
spikelet 3
3a. Spikelets in pairs in a spikelike panicle, one perfect, the
other staminate or neuter, the pair falling together- 63. LYCUBUS.
3b. Spikelets all alike 4
4a. Glumes long-awned_: 62. POLYPOGON.
4b. Glumes awnless 5
5a. Rachilla not prolonged behind the palea ; panicle
dense and spikelike ; glumes united toward the
base, ciliate on the keel 61. ALOPECURUS.
5b. Rachilla prolonged behind the palea ; panicle nar-
row or open, not dense; glumes not united, not
ciliate on the keel , 6
6a. Panicle narrow; lemma with a slender bent
twisted awn from the bifid apex 60. LIMNODEA.
6b. Panicle open and drooping ; lemma with a minute
straight awn just below the entire apex 59. CINNA.
2b. Rachilla articulate above the glumes 7
7a. Fruit dorsally compressed, indurate, smooth and shining,
awnless 74. MILIUM.
7b. Fruit laterally compressed or terete, awned or awnless 8
8a. Fruit indurate, terete, awned, the nerves obscure ; callus
well developed, oblique, bearded 9
9a. Awn trifid, the lateral divisions sometimes short,
rarely obsolete (when obsolete no line of demar-
cation between awn and lemma as in the
next) 77. ABISTIDA.
9b. Awn simple, a line of demarcation between the awn
and the lemma 10
lOa. Awn persistent, twisted and bent, several to
many times longer than the slender fruit ; callus
sharp-pointed 76. STIPA.
lOb. Awn deciduous, not twisted, sometimes bent,
rarely more than 3 or 4 times as long as the
plump fruit ; callus short, usually obtuse- 75. ORYZOPSIS.
8b. Fruit thin or firm, but scarcely indurate, if firm, the
nerves prominent or evident ; callus not well devel-
oped 11
lla. Glumes longer than the lemma (lemma equaling
the glumes in Agrostis spica-venti, A. aequivalvis,
and A. thurberiana) 12
12a. Panicle feathery, capitate, nearly as broad as
long; spikelets woolly 66. LAGURUS.
12b. Panicle not feathery; spikelets not woolly 13
13a. Glumes compressed-carinate, abruptly mu-
cronate, stiffly ciliate on the keels;
panicle dense, cylindric or ellipsoid- 64. PHLEUM.
13b. Glumes not compressed-carinate, not ciliate 14
GENERA OF GRASSES OF THE UNITED STATES. 15
Key to the genera of Agrostideae Continued.
14a. Glumes saccate at base ; lemma long-awned ; inflorescence
contracted, shining 65. GASTEIDIUM.
14b. Glumes not saccate at base ; lemma awned or awnless ;
panicles open or contracted ] 15
15a. Florets bearing a tuft of hairs at the base from the
short callus, the hairs at least half as long as the
lemma; palea present 53. CALAMAGBOSTIS.
15b. Florets without hairs at the base or with short
hairs rarely as much as half the length of the
lemma (Agrostis hallii) ; palea usually small or
wanting 56. AGROSTIS. "
lib. Glumes not longer than the lemma, usually shorter (the awn tips
longer in Muhlenbergia racemosa) 16
16a. Lemma awned from the tip or mucronate, 3 to 5 nerved (lateral
nerves obsolete in Muhleribergia rcpcns) 17
17a. Rachilla prolonged behind the palea; floret stipitate.
73. BBACHYELYTETJM.
17b. Rachilla not prolonged ; floret not stipitate 68. MUHLENBERGIA.
16b. Lemma awnless or awned from the back 'i, 18
18a. Florets bearing a tuft of hairs at the base from the short
callus; lemma and palea chartaceous, awnless 19
19a. Panicles spikelike; rachilla prolonged 54. AMMOPHILA.
19b. Panicles open ; rachilla not prolonged 55. CALAMOVILFA.
18b. Florets without hairs at base 20
20a. Nerves of lemma densely silky 70. BLEPHARONEURON.
20b. Nerves of lemma not silky 21
21a. Caryopsis at maturity falling from the lemma and
palea; seed loose in the pericarp, this usually
opening when ripe; lemma 1-nerved 22
22a. Inflorescence capitate in the axils of broad
bracts 71. CRYPSIS.
22b. Inflorescence an open or contracted panicle.
69. SPOROBOLUS.
21b. Caryopsis not falling from the lemma and palea,
remaining permanently inclosed in them; seed
adnate to the pericarp 23
23a. Panicles few-flowered, slender, rather loose;
glumes minute, unequal, the first often want-
ing; a low arctic alpine perennial 57. PHIPPSIA.
23b. Panicle many-flowered, spikelike ; glumes well
developed, about equal 24
24a. Panicle short, partly inclosed in the sheath ;
low annual 72. HELEOCHLOA.
24b. Panicle elongate; perennial 67. EPICAMPES.
TRIBE 6, NAZIEAE.
Spikelets subsessile in short spikes of 2 to 5 (single in Oster-
damia), each spike falling entire from the continuous axis, usually
1-flowered, all perfect, or perfect and staminate together in the same
spike; glumes usually firmer than the lemma and palea, sometimes
awned, the lemma awnless.
This small and unimportant tribe is known also as Zoysieae. In
Osterdamia the spikelets are single and have only one glume, this
16 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
coriaceous, much firmer than the lemma and palea, the palea some-
times obsolete.
Key to the yenera of Nazieae.
la. Spikelets single ; first glume wanting 79. OSTERDAMIA.
Ib. Spikelets in clusters of 2 to 5 ; first glume present 2
2a. Spikelets bearing hooked spines on the second glume, the group
forming a little bur 78. NAZIA.
2b. Spikelets not bearing hooked spines, mostly cleft and awned 3
3a. Groups of spikelets erect, the spike not one-sided 80. HILABIA.
3b. Groups of spikelets nodding along one side of the delicate
axis 81. AEGOPOGON.
TRIBE 7, CHLOKIDEAE.
Spikelets 1 to several flowered, in 2 rows on one side of a con-
tinous rachis forming one-sided spikes or spikelike racemes, these
solitary, digitate, or racemose along the main axis.
A large and rather important tribe, confined mostly to warm
regions. The group is heterogeneous, the only common character
of the genera (aside from the characters that place them in Poatae)
being the arrangement of the spikelets in one-sided spikes. Chloris
and the allied genera form a coherent group, in which the spikelet
consists of one perfect floret and, above this, one or more modified
or rudimentary florets. Leptochloa, Eleusine, and their allies, with
several-flowered spikelets, are more nearly related to certain genera
of Festuceae. The spike is reduced to two or three spikelets or even
to one spikelet and is sometimes deciduous from the main axis in
Cathestecum and in some species of Bouteloua. In Campulosus
there are two sterile florets below the perfect one.
Key to the genera of Chlorideae.
la. Plants monoecious or dioecious ; a low stoloniferous perennial- 98. BTJLBIUS.
Ib. Plants with perfect flowers 2
2a. Spikelets with more than one perfect floret 3
3a. Inflorescence a few-flowered head or capitate panicle hidden
among the sharp-pointed leaves; a low spreading an-
nual 97. MUNBOA.
3b. Inflorescence exserted 4
4a. Spikes solitary, the spikelets distant, appressed, sev-
eral-flowered 83. TEIPOGON.
4b. Spikes more than 1 5
5a. Spikes numerous, slender, racemose on an elongate
axis 82. LEPTOCHLOA.
5b. Spikes few, digitate or nearly so 6
6a. Rachis of spike extending beyond the spike-
lets 85. DACTYLOCTENITJM.
6b. Rachis not prolonged 84. ELEUSINE.
2b. Spikelets with only 1 perfect floret, often with additional imper-
fect florets above__ 7
GENEKA OF GRASSES OF THE UNITED STATES. 17
Key to the genera of Chlorideac Continued.
7a. Spikelets without additional modified florets, the rachilla sometimes
prolonged 8
Sa. Rachilla articulate below the glumes, the spikelets falling entire- 9
9a. Glumes unequal, narrow 90. SPAETINA.
9b. Glumes equal, broad and boat shaped 89. BECKMANNIA.
8b. Rachilla articulate above the glumes 10
lOa. Spikes digitate; rachilla prolonged 86. CAPRIOLA.
lOb. Spikes racemose along the main axis ; rachilla not prolonged. 11
Ha. Spikes slender, divaricate, the main axis elongating and
becoming loosely spiral in fruit 88. SCHEDONNARDUS.
lib. Spikes short and rather stout, appressed, the axis un-
changed in fruit 87. WUXKOMMIA.
7b. Spikelets with 1 or more modified florets above the perfect one_ 12
12a. Spikelets with 2 sterile florets below the perfect one; second
glume bearing a squarrose spine on the back; spike single,
recurved 91. CAMPULOSUS.
12b. Spikelets with no sterile florets below the perfect one; second
glume without a squarrose spine ; spikes usually several 13
13a. Spikes digitate or nearly so 14
14a. Fertile lemma 1-awned or awnless 93. CHLOBIS.
14b. Fertile lemma 3-awned 94. TKICHLOEIS.
13b. Spikes racemose along the main axis 15
15a. Spikelets distant, appressed ; spikes slender, elongate.
92. GYMNOPOGON.
15b. Spikelets contiguous or crowded, not appressed ; spikes
usually short and rather stout -. 16
16a. Spikelets 3 in each spike, the 2 lateral staminate or
rudimentary ; spikes falling entire 96. CATHESTECUM.
16b. Spikelets 2 to many (rarely 1) in each spike, all
alike ; spikes usually persistent, the florets falling.
95. BOUTELOUA.
TRIBE 8, PHALARIDEAE.
Spikelets with one perfect terminal floret and, below this, a pair of
staminate or neuter florets.
A small tribe of about six genera, only three of which are found
in the United States. In Phalaris the lateral florets are reduced to
minute scalelike lemmas closely appressed to the edges of the fertile
floret. In Torresia the lateral florets are staminate and as large as
the fertile floret.
Key to the genera of Phalarideae.
la. Lateral florets staminate ; spikelets brown and shining 99. TORRESIA.
Ib. Lateral florets neuter ; spikelets green or yellowish 2
2a. Lateral florets reduced to small awnless scalelike lemmas ; spike-
lets much compressed laterally - 101. PHALARIS.
2b. Lateral florets consisting of awned hairy sterile lemmas exceed-
ing the fertile floret ; spikelet terete 100. ANTHOXANTHTJM,
97769 19 Bull. 772 2
18 BULLETIN 112, U. S. DEPARTMENT OF AGRICULTURE.
TRIBE 9, ORYZEAE.
Spikelets 1-flowered, perfect, strongly laterally compressed, panic-
ulate ; glumes reduced or wanting ; palea apparently 1-nerved ; stam-
ens 6.
A small tribe whose affinities are not evident. It includes rice, the
important food plant.
- Key to the genera of Oryzeae.
Glumes minute; lemma often awned 102. ORYZA.
Glumes wanting; lemma awnless 103. HOMALOCENCHRUS.
TRIBE 10, ZIZANIEAE.
Spikelets unisexual, the pistillate terete or nearly so; glumes
shorter than the lemma, usually one or both obsolete, the pedicel dis-
articulating below the spikelet.
A small tribe of uncertain affinities; the species aquatic or sub-
aquatic, of no economic importance except the Indian rice (Zizania).
Key to the genera of Zizanieae.
la. Culms slender ; plants low ; staminate and pistillate spikelets borne in
separate inflorescences 2
2a. Inflorescence a few-flowered spike ; plants not stoloniferous.
107. HYDROCHLOA.
2b. Inflorescence a panicle; plants stoloniferous 106. LUZIOLA.
Ib. Culms robust ; plants tall ; staminate and pistillate spikelets borne in
the same panicle - 3
3a. Plants annual; pistillate spikelets on the ascending upper
branches, the staminate on the spreading lower branches of the
panicle '. 105. ZIZANIA.
3b. Plants perennial; pistillate spikelets at the ends, the staminate
below on the same branches of the panicle 104. ZIZANIOPSIS.
TRIBE 11, MELINIDEAE.
Spikelets disarticulating below the glumes, these very unequal, the
first minute, the second and the sterile lemma equal, membranaceous,
strongly nerved, the latter bearing a slender awn from the notched
summit ; fertile lemma and palea thinner in texture, awnless.
A tribe of about a dozen genera, none of w r hich is represented in
the United States. The only economic species is Melinis minutiftora
(seep. 212).
TRIBE 12, PANICEAE.
Spikelets with one perfect terminal floret and below this a sterile
floret and two glumes; fertile lemma and palea indurate or at least
firmer than the glumes and sterile lemma; articulation below the
spikelet.
A large tribe, confined mostly to warm regions, and containing few
economic species. The first glume is wanting in some genera, such
as Paspalum, and rarely the second glume also (Eeimarochloa).
GENERA OF GRASSES OF THE UNITED STATES. 19
The spikelets are usually awnless, but the glumes and sterile lemma
are awned in Echinochloa and Oplismenus, and the second glume and
sterile lemma in Tricholaena. In Eriochloa and in some species of
Brachiaria the fertile lemma is awn-tipped. In Chaetochloa there
are, beneath the spikelet, one or more bristles, these representing
sterile branchlets. In Pennisetum similar bristles form an involucral
cluster, falling with the spikelet. In Cenchrus the bristles are
united, forming a bur. The spikelets are of two kinds in Amphi-
carpon, aerial and subterranean. The culms are woody and perennial
in Lasiacis and Olyra.
Key to the genera of Paniceae.
la. Spikelets of two kinds 2
2a. Spikelets all perfect, but those of the aerial panicle not perfect-
ing grains; the fruitful spikelets borne on subterranean
branches 127. AMPHICARPON.
2b. Spikelets unisexual, the pistillate above, the staminate below on
the branches of the same panicle ; blades broad, elliptic.
OLYRA. (See p. 252.)
Ib. Spikelets all of one kind 3
3a. Spikelets sunken in the cavities of the flattened corky rachis.
112. STENOTAPHEUM.
3b. Spikelets not sunken in the rachis 4
4a. Spikelets subtended or surrounded by 1 to many distinct or
more or less connate bristles, forming an involucre 5
5a. Bristles persistent, the spikelets deciduous- 124. CHAETOCHLOA.
5b. Bristles falling with the spikelets at maturity G
6a. Bristles not united at base, slender, often plumose.
125. PENNISETUM.
6b. Bristles united into a burlike involucre, the bristles
retrorsely barbed 126. CENCHRUS.
4b. Spikelets not subtended by bristles 7
7a. Glumes or sterile lemma awned (awn short and con-
cealed in the silky hairs of the spikelet in Tricholaena,
awn reduced to a point in Echinochloa colonuni) 8
8a. Inflorescence paniculate ; spikelets silky_ 123. TRICHOLAENA.
8b. Inflorescence of unilateral simple or somewhat com-
pound racemes along a common axis; spikelets
smooth or hispid, not silky 9
9a. Blades lanceolate, broad and thin ; glumes 2-
lobed, awned from between the lobes.
121. OPLISMENUS.
9b. Blades long and narrow ; glumes awned from
the tip 122. ECHINOCHLOA.
7b. Glumes and sterile lemma awnless 10
lOa. Fruit cartilaginous-indurate, flexible, usually dark
colored, the lemma with more or less prominent
white hyaline margins, these not inrolled 11
Ha. Spikelets covered with long silky hairs, ar-
ranged in racemes, these panicled 109. VALOTA.
lib. Spikelets glabrous or variously pubescent but
not long-silky 12
20 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Key to the genera of Paniceae* Continued.
12a. Spikelets in slender racemes more or less digitate at the
summit of the culms 110. SYNTHEBISMA.
12b. Spikelets in panicles 13
13a. Fruiting lemma boat shaped; panicles narrow.
108. ANTHAENANTIA.
13b. Fruiting lemmas convex; panicles diffuse 111. LEPTOLOMA.
lOb. Fruit chartaceous-indurate, rigid 14
14a. Spikelets placed with the back of the fruit turned away from
the rachis of the racemes, usually single (not in pairs) 15
15a. First glume and the rachilla joint forming a swollen ring-
like callus below the spikelet 113. ERIOCHLOA.
15b. First glume present or wanting, not forming a ringlike
callus below the spikelet 16
16a. First glume present ; racemes racemose along the main
axis , 114. BRACHIARIA.
16b. First glume wanting ; racemes digitate or subdigitate.
115. AXONOPUS.
14b. Spikelets placed with the back of the fruit turned toward the
rachis of the spikelike racemes, or pedicellate in panicles 17
17a. Fruit long-acuminate; both glumes wanting- 116. REIMAROCHLOA.
17b. Fruit not long-acuminate, at least one glume present 18
ISa. First glume typically wanting; spikelets plano-convex,
subsessile in spikelike racemes 117. PASPALUM.
ISb. First glume present ; spikelets usually in panicles 19
19a. Second glume inflated-saccate, this and the sterile
lemma much exceeding the stipitate fruit.
120. SACCIOLEPIS.
19b. Second glume not inflated-saccate 20
20a. Culms woody and bamboolike; fruit with a
tuft of down at the apex 119. LASIACIS.
20b. Culms herbaceous ; no tuft of down at the apex
of the fruit 118. PANICUM.
TRIBE 13, ANDROPOGONEAE.
Spikelets in pairs along a rachis, the usual arrangement being
one of the pair sessile and fertile, the other pedicellate and staminate
or neuter, or rarely wanting, only the pedicel present ; fertile spike-
let consisting of one perfect terminal floret and, below this, a stami-
nate or neuter floret, the lemmas thin or hyaline, and two awnless
glumes, one or usually both firm or indurate.
A large tribe, confined mostly to warm regions. The rachis is
usually jointed, disarticulating at maturity, with the spikelets at-
tached. In a few genera it is thickened. Sometimes the racemes are
shortened to 1 or 2 joints and borne on branches, the whole forming a
panicle (as in Holcus and Sorghastrum) instead of a series of
racemes. In a few genera the spikelets of the pair are alike. In
Traclwpogon the fertile spikelet is pedicellate and the sterile one
nearly sessile.
GENERA OF GRASSES OF THE UNITED STATES. 21
Key to the genera of Andropogoneae.
la. Spikelets all perfect, surrounded by a copious tuft of soft hairs 2
2a. llacliis continuous, the spikelets falling ; spikelets of the pair un-
equally pedicellate 3
3a. Racemes in a narrow spikelike panicle, spikelets awn-
less > 128. IMPERATA.
3b. Racemes in a broad fan-shaped panicle; spikelets awned.
129. MlSCANTHtJS.
2b. Rachis breaking up into joints at maturity with the spikelets at-
tached ; one spikelet sessile, the other pedicellate 4
4a. Spikelets awnless 130. SACCHARUM.
4b. Spikelets awned 131. ERIANTHTJS.
Ib. Spikelets unlike, the sessile perfect, the pedicellate sterile (sessile
spikelet staminate, pedicellate spikelet perfect in Trachypogon) 5
5a. Pedicel thickened, appressed to the thickened rachis joint (at
least parallel to it) or adnate to it; spikelets awnless, ap-
pressed to the joint G
6a. Rachis joint and pedicel adnate, forming a short flat joint,
this sunken in the open side of the globose first glume of
the sessile spikelet; sterile spikelet conspicuous 140. RYTILIX.
6b. Rachis joint and pedicel distinct, the sessile spikelet ap-
pressed to them, its first glume lanceolate 7
7a. Racemes subcylindric ; rachis joints and pedicels glabrous,
much thicker at the summit, the spikelets sunken in the
hollow below ; sterile spikelet rudimentary 130. MANISURIS.
7b. Racemes flat ; rachis joints and pedicels woolly, not much
thicker at the summit; sterile spikelet staminate or neu-
ter 138. ELYONURUS.
5b. Pedicel not thickened (if slightly so the spikelets awned), neither
appressed nor adnate to the rachis joint, this usually slender ;
spikelets usually awned ^ 8
8a. Fertile spikelet with a hairy-pointed callus, formed of the
attached supporting rachis joint or pedicel ; awns strong 9
9a. Racemes reduced to a single joint, long-peduncled in a
simple open panicle 135. RHAPHIS.
9b. Racemes of several to many joints, single 10
lOa. Primary spikelet subsessile, sterile, persistent on
the continuous axis after the fall of the fertile pedi-
cellate spikelet, the pedicel forming the callus.
137. TRACHYPOGON.
lOb. Primary spikelet sessile, fertile; pedicellate spike-
let sterile ; lower few to several pairs of spikelets all
staminate or neuter 136. HETEROPOGON.
8b. Fertile spikelet without a callus, the rachis disarticulating
immediately below the spikelet ; awns slender 11
lla. Racemes of several to many joints, solitary, digitate,
or aggregate 132. ANDROPOGON.
lib. Racemes reduced to one or few joints, these mostly
peduncled in a subsimple or compound panicle 12
12a. Pedicellate spikelets staminate 133. HOLCUS.
12b. Pedicellate spikelets wanting, the pedicel only
present 134. SORGHASTRUM.
BULLETIN 772, XT. S. DEPARTMENT OF AGRICULTURE.
TRIBE 14, TEIPSACEAE.
celets unisexual, the staminate in pairs, or sometimes in threes
2-flowered, the pistillate usually single, 2-flowered, the lower floret
sterile, imbedded in hollows of the thickened articulate axis and fall-
ing attached to the joints, or inclosed in a thickened involucre or
sheath or, in Zea, crowded in rows on a thickened axis (cob) ; glumes
membranaceous or thick and rigid, awnless; lemmas and palea
hyaline, awnless. Plants monoecious.
This small tribe of seven genera is scarcely more than a subtribe
of Andropogoneae. It is also known as Maydeae.
Key to the genera of Tripsaceae.
la. Staminate and pistillate spikelets in separate inflorescences, the first
in a terminal tassel, the second in the axils of the leaves 2
2a. Pistillate spikes distinct, the spikelets embedded . in the hardened
rachis, this disarticulating at maturity 142. ETJCHLAENA.
2b. Pistillate spikes grown together forming an ear. the grains at
maturity much exceeding the glumes 143. ZEA.
Ib. S-taminate and pistillate spikelets in separate portions of the same
spike, the pistillate below 3
3a. Spikes short, the 1 or 2 flowered pistillate portion inclosed in
a beadlike sheathing bract 144. Coix.
3b. Spikes many-flowered, the pistillate portion breaking up into
several 1-seeded joints; no beadlike sheathing bract 141. TEIPSACUM.
DESCRIPTIONS OF THE GENERA.
1. BAMBOSEAE, THE BAMBOO TRIBE.
1. ARTJNDINARIA Michx.
Spikelets few to many flowered, large, compressed, the rachilla
disarticulating above the glumes and between the florets ; glumes un-
.equal, shorter than the lemmas, the first sometimes wanting ; lemmas
acute or acuminate or mucroiiate, faintly many-nerved; palea about
as long as the lemma, prominently 2-keeled.
Shrubs or tall reeds, with woody perennial branching culms, flat
blades with petioles articulate with the sheaths, and loose racemes
or panicles. Species about 25, in the Tropics of both hemispheres;
2 species in the southeastern United States.
Type species: Arnndinarin macrosperma Michx.
Arundinaria Michx., Fl. Bor. Amer. 1 : 73. 1803. One species described.
Miegin Pers., Syn. PI. 1:101. 1805. A single species, based on Arundinaria
macrosperma Michx., is included.
Macronax Raf., Med. Repos. ser. 2. 5: 353. 1808. Based on "The Arundi-
naria of Michaux."
Our two species, Anmdinaria tecta (Walt.) Muhl. (fig. 1) and A.
macrosperma (PL I), are the only native representatives of the tropi-
cal tribe Bamboseae, or Bambuseae, the bamboos. Our species are
known, respectively, as small and large cane. Both flower infre-
Bui. 772, U. S. Dept. of Agriculture.
PLATE
LARGE CANE (ARUNDINARIA MACROSPERMA). INFLORESCENCE, LEAVES, FLORETS,
AND RIPE GRAINS.
Bui. 772, U. S. Dept. of Agriculture.
PLATE II,
MEADOW FESCUE (FESTUCA ELATIOR) IN FLOWER.
GENERA OF GRASSES OF THE UNITED STATES. 23
FIG. 1. Small cane, Arundinaria tccta. Flowering shoot and leafy branch, X a ; spike-
let and floret, X 2.
24 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
quently. The first is rarely over G feet tall, with drooping blades^
the inflorescence on leafless or nearly leafless shoots from the base of
the plant. This is found from Maryland southward. The other
species grows to a height of as much as 25 or 30 feet and forms, in
the alluvial river bottoms of the Southern States, dense thickets
called canebrakes. The racemes are borne on leafy branches, the
species flowering less frequently than the small cane.
Stock are fond of the young plants and of the leaves and seeds, and
both species furnish much forage in localities where they are abun-
dant. The young shoots are sometimes used as a potherb. The
stems or culms of the large cane are used for fishing rods, pipestems,
baskets, mats, light scaffolding, and for a variety of other purposes.
2. FESTUCEAE, THE FESCUE TRIBE.
2. BROMTJS L., the brume-grasses.
. Spikelets several to many flowered, the rachilla disarticulating
above the glumes and between the florets ; glumes unequal, acute, the
first 1 to 3 nerved, the second usually 3 to 5 nerved ; lemmas convex
on the back or keeled, 5 to 9 nerved, 2-toothed at the apex, awnless or
usually awned from between the teeth; palea usually shorter than
the lemma.
Annual or perennial, low or rather tall grasses, with closed sheaths,
flat blades, and open or contracted panicles of large spikelets. Species
about 100, in temperate regions; about 43 species in the United
States, of which -IT are introductions, mostly from Europe.
Type species: Bromus sccalinus L.
Bronras L., Sp. PI. 76, 1753 ; Gen. PI., eel. 5, 33. 1754. Linnaeus describes 11
species, all but the last 2 of which are still retained in the genus. The cita-
tion given after Brornus in the Genera I'lantarum is "Mont. 32." This" refers
to figure 32 in the plate accompanying Monti's Catalog! Stirpium Agri Bononiensis
Prodromus, published in 1719. This figure represents a spikelet of Bromus
secalinus, or of a closely allied species. As Brotnu* sct-uH-mis is the first species
described in the Species Plantarum and was described in the flora of Sweden,
this species is chosen as the type.
Ceratochloa Beauv., Ess. Agrost. 75, pi. 15, f. 7. 1812. A single species in-
cluded. Festuca unioloides Willd., which is the basis of Bromus it mol aides
(Willd.) H. B. K.
Zerna Panz., Denkschr. Baier. Akad. Wiss. Miiench. 4: 296. 1813. (Ideen
Gatt. Graser 46, pi. 11, f. 3.) Eleven species are included. Bromus stcrilis
L., the one figured, is taken as the type.
Serrafalcus Part., Rar. PI. Sic. 2: 14. 1840. Six species are included. Bro-
mus rac-cmosus L., on which the first species is based, is taken as the type.
Forasaccus Bubani, Fl. Pyren. 4 : 380. 1901. Proposed for Bromus L., not
Bromus of the ancients, which is said to be wild oats.
The section Ceratochloa has large compressed spikelets with com-
pressed-keeled glumes and lemmas. One species, Bromus unioloides
(Willd.) H. B. K., is cultivated as a forage grass under the name
of rescue grass or Schrader's brome-grass. This is an annual or bi-
ennial grass 1 to 2 feet tall, with pubescent sheaths and narrow pani-
cles of smooth spikelets as much as an inch long, the lemmas acumi-
GENERA OF GRASSES OF THE UNITED STATES. 25
nate or awn-tipped. Rescue grass is a native of South America and
is cultivated occasionally in our Southern States for winter forage.
The other species of this section are natives of the western half of
the United States. They are all perennials and have large awned
spikelets. Bromus carinatus Hook, and Am. and B. marginatus
Nees are common on the Pacific coast. They have pubescent or
scabrous spikelets, the first with an awn longer than the lemma, the
second with an awn shorter than the lemma. Bromus carinatus often
appears like an annual, flowering the first year.
The species of Bromus in which the spikelets are not compressed-
keeled fall into two rather well-marked groups, perennials and an-
nuals. The most important species of the first group is Bromus
inermis Leyss., a European species known also as awnless brome-
grass, Hungarian brome-grass, smooth brome-grass, and brome-grass.
It is erect, 2 to 3 feet tall, with creeping rhizomes and narrow, many-
flowered panicles with erect or ascending branches and smooth nar-
row spikelets about an inch long, the lemmas acute, awnless, or nearly
so. Awnless brome-grass is cultivated for hay and pasture in the
northern portion of the Great Plains from northern Kansas to
Minnesota and Montana. It is more drought resistant than timothy
and in the region mentioned can be grown farther west than that
species, but does not thrive south of central Kansas. All the other
perennial species are natives except B. erectus, occasionally intro-
duced from Europe, and all have distinctly awned lemmas. Bromus
purgans L. is a common woodland species in the Eastern States.
This has an open drooping panicle with nearly terete spikelets, the
lemmas pubescent over the back. The closely allied and equally com-
mon B. ciliatus L. (fig. 2) differs in having lemmas glabrous on the
back and pubescent on the margins only. Several species are found
in the Western States, B. porteri (Coult.) Nash, with close drooping
panicle and softly pubescent spikelets, being common in the Rocky
Mountains.
The group of annuals includes weedy species introduced mostly
from Europe. The best known of these in the Eastern States is
Bromus seealinus (fig. 3), chess or cheat, a weed of waste places and
sometimes infesting grain fields. Formerly it was believed by the
credulous that under certain conditions wheat changed into chess.
Chess in a wheat field is due to chess seed in the soil or to chess seed
in the wheat sown. Chess is a smooth grass 1 to 3 feet tall, with flat
blades and open duooping panicles of smooth turgid spikelets, the
lemmas broad and inrolled above, the awn about as long as the lemma.
Bromus commutatus Schrad. differs in having pubescent sheaths.
On the Pacific coast the annual species of Bromus have become
conspicuous. They thrive on all open ground at lower altitudes in
26 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 2. Wild brome-grass, Bromus ciliatus. Plant, X i ; spikelet and floret, X 5.
GENEKA OF GRASSES OF THE UNITED STATES. 27
FIG. 3. Chess (cheat), Bromus secalinus. Plant, X 2 ; spikelet and floret, X 5.
28 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
spring and early summer, and on the approach of the summer dry
season they ripen their seed and turn brown. They often cover
vast areas and have become a great pest. The commonest species are
B. rub&ns L., with contracted panicles of narrow usually purplish
spikelets; B. hordeaceus L., with compact panicles of short turgid
usually pubescent spikelets like those of B. secodmus; B. villosus
Forsk., with open rather few-flowered panicles and narrow spike-
lets with awns as much as 2 inches long; and B. tectorum L. (fig. 4),
a rather small softly pubescent species, with drooping panicles of
narrow spikelets. Bromws trimi Desv., found chiefty in the desert
regions of California, introduced from Chile, is peculiar in having
a bent awn twisted below. Bromus arenarius Labill., a recent intro-
duction from Australia, is becoming common. This has an open
panicle with capillary curved pedicels and short, pubescent spikelets.
The perennial species of Bromus are important forage grasses on
the mountain ranges of the Western States. The annual species are
good forage grasses w T hen they are young, but they are rather eva-
nescent. The fruits of B. villosus. and B. rubens and their allies are
injurious to stock, the sharp-pointed florets working their way into
the eyes and nostrils. BromMs secalmm is grown for hay in Wash-
ington, in Oregon, and in Georgia.
For a revision of the species of Bromus found in the United States,
see Shear, U. S. Dept. Agr., Div. Agrost. Bull. 23. 1900.
3. FESTUCA L., the fescue grasses.
Spikelets few to several flowered, the rachilla disarticulating above
the glumes and between the florets; glumes narrow, acute, unequal,
the first sometimes very small; lemmas rounded on the back, mem-
branaceous or somewhat indurate, 5-nerved, the nerves often obscure,
acute or rarely obtuse, awned from the tip or rarely from a minutely
bifid apex.
Annual or perennial low or rather tall grasses of varied habit, the
spikelets in narrow or open panicles. Species about 100, in the tem-
perate and cool regions; about 40 species in the United States, 7 of
which are introductions from Europe.
Type species: Festuca ovina L.
P'estuca L., Sp. PI. 73, 1753; Gen. PI., ed. 5, 33. 1754. Linnaeus describes 11
species. Festuca ovina is chosen as the type, as it is the first of the original
species that is economic and is described in the flora of Sweden. Most of the
original species are still retained in Festuca but F. flecumbens is now placed
in Sieglingia, F. fluitans in Panicularia, and F. cristata in Koeleria (.K.
phleoides).
Vulpia Gmel., Fl. Badens. 1: 8. 1805. One species, V. 'myuros, based on
Festuca myuros L., is described, and two species of Festuca having a single
stamen are mentioned in a note. Festuca myuros is taken as the type.
Schedonorus Beauv., Ess. 'Agrost. 99, pi. 19, f. 2. 1812. The first of the 25
species included and the one figured is "Bromus elatior" (L.) KoeL, based on
Festuca elatior. The figure shows a floret with a short awn below the minutely
bidentate apex, as found in occasional specimens of F. elatior, which species is
taken as the type.
GENERA OF GRASSES OF THE UNITED STATES.
29
FIG. 4. Downy brome-grass, Bromm tectorum. Plant, X J ; splkelet and floret, X 5.
30
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Dasiola Raf., Neogenyt. 4. 1825. " Type Festuca monandra " Ell., renamed
D. elliottea Raf. This is F. scinrea Nutt.
Chloaninia Raf.,
Neogenyt. 4. 1825.
Two species are in-
cluded, Festuca te-
ncUtt and F. liromoi-
dcs. The first, which
is F. octo flora Walt.,
is taken as the type.
Hesperochloa (Pi-
per) Rydb., Bull.
Torrey Club 39: 106.
1912. Based on Fes-
tuca subgenus Hes-
perochloa Piper, the
type and only species
of which is F. confi.n-ix
Vasey.
Wasatchia Jones,
Contr. West. Bot. 14 :
16. 1912. A single
species is included,
ir. Jcinffii (Watson)
Jones, based on Po<i
kluyii Watson, which
is the same as F. con-
finis Vasey.
Gnomonia Lunell,
Amer. Midi. Nat. 4:
224. 1915. A new
name proposed for
Festuca L., not Do-
donaeus, 1551.
The subgenus
Yulpia, including
annuals with most-
ly narrow panicles
and floAvers with
but one stamen, is
represented in the
United States by
13 species, 2 of
which, Festuca
inyuros L. and F.
ftromoidcs L., are
introductions
from Europe.
Festuca octojlora
Walt. (fig. 5),
with spikelets usu-
ally more than
5 -flowered and
hard terete gla-
brous or scabrous
lemmas with no scarious margin, is common throughout the United
States. Several native species of this subgenus are found on the
Pacific coast.
FIG. 5. Festuca octoflora.
spikelet and floret,
GENERA OF GRASSES OF THE UNITED STATES. 31
The subgenus Hesperochloa includes a single species Festuca
confinis Vasey, a stout tufted perennial with creeping rhizomes, firm
flat blades, and narrow panicles of awnless spikelets.
The remaining species, all perennials, are placed in the subgenus
Eufestuca. Mountain bunch-grass (F. viridula Vasey) with nar-
row flat or loosely involute blades and awnless spikelets is common
in the subalpine meadows of the northwestern mountains where it
constitutes an important part of the forage. Festv)ca subulate Trin.,
a common woodland species of the Northwestern States, has flat thin
blades and very open panicles of long-awned spikelets. Much re-
sembling this is F. sulmli flora Scribn., which is peculiar in having
a stipelike elongation at the base of the florets. An allied Califor-
nian species, F. elmeri Scribn. and Merr.^ias spikelets like F. subulata,
but the awn arises between the two minute teeth of the lemma. Fes-
tuca obtusa, Spreng. is an eastern woodland species with very loose
sparingly 'branched panicle and few awnless spikelets. The largest
species of the genus in the United States is F. calif omica Vasey,
found in dry woods of western California and Oregon. This grows
in large tufts, with culms as much as 5 feet tall, hard flat or loosely
involute blades, pilose on the collar, and large panicles.
The type species, Festuca ovina, is the representative of a large
group of varieties or closely allied species in Europe. Festuca omna
itself is cultivated as a lawn or pasture grass under the name of
sheep's fescue. It is a tufted grass 6 to 18 inches tall with firm, short,
involute blades, crowded at the base of the slender culms, and narrow
panicles of short-awned spikelets. This grass is used in mixtures
for sterile or stony soil. Three allied European species are used in
the same way but especially in mixtures for lawns. These are F.
durmscula L., hard fescue (a species rare in America), with blades
about 1 mm. broad; F. heterophyUa~Lsim., with flat stem blades; and
F. capillata Lam., with very fine blades and awnless spikelets. Eed
fescue, F. rubra L. (fig. 6), differs in the loosely tufted culms with
decumbent usually red bases. This is native in both Europe and
America. Two species allied to F. ovina are native in the Western
States and are both important range grasses. These are F. idahoensis
Elmer (F. ingrata (Hack.) Kydb.), blue bunch-grass, with pale
narrow stiff harshly scabrous blades 6 to 15 inches long, and awned
spikelets, common from British Columbia to Colorado and Cali-
fornia ; and F. arizonica Vasey, Arizona fescue, with nearly awnless
spikelets, found in northern Arizona and southern Utah.
The most important cultivated species of the genus is Festuca
elatior L.. meadow fescue (PI. II ; fig. 7) . This is a smooth perennial,
1 to 4 feet high, with flat blades and a narrow but rather loose panicle
1 to 8 inches long, the awnless spikelets about half an inch long.
Meadow fescue is cultivated for hay and pasture in the humid region,
32 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
especially in Tennessee, Missouri, and eastern Kansas. There are two
agricultural varieties of this species. The taller form with larger
more open panicle is distinguished as tall fescue. The form more
FIG. 6. Red fescue, Festuca rubra. Plant, X 1 ; spikelet and floret, x 5.
GENERA OF GRASSES OF THE UNITED STATES. 33
FIG. 7. Meadow fescue, Festuca elatior. Plant, X \ ; spikelet and floret, X 5.
commonly cultivated, usually called meadow fescue, is 2 or 3 feet
tall and has a nearly simple panicle, sometimes racemose above and
slightly branched at the base. In eastern Kansas the incorrect name
English bluegrass is sometimes applied to this species,
97769 19 Bull. 772 3
34 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
For a revision of the species of Festuca found in North America,
see Piper, Contr. U. S. Nat. Herb. 10 : 1-48, pi. 1-15. 1906.
Scleropoa Griseb., Spicil. Fl. Kumel. 2 : 431. 1844.
The one species. Scleropoa rigida (L.) Griseb., a native of southern
Europe, is sparingly introduced in the United States, mostly as a
ballast plant. It is a low annual with racemes of spikelets resembling
those of Puccinellia. The glumes are 1-nerved, the lemmas convex
on the back and obscurely nerved. The type is Poa rigida L.
Brachypodium Beauv., Ess. Agrost. 100, 155. 1812.
One species, Brachypodium distackyon (L.) Beauv., of Europe,
has been found on ballast at Portland, Oreg., and Camden, N. J. It
is a low tufted annual, with stiff culms ending in a raceme of 1 to
few short-pediceled, many-flowered cylindric spikelets, the awnecl
lemmas rounded on the back, the paleas stiffly ciliate on the keels.
4. PANICULARIA Heister.
(Glyceria R. Br.)
Spikelets few to many flowered, subterete or slightly compressed,
the rachilla disarticulating above the glumes and between the florets ;
glumes unequal, short, obtuse or acute, usually scarious, mostly 1-
nerved ; lemmas broad, convex on the back, firm, usually obtuse, awn-
less, scarious at the apex, 5 to 9 nerved, the nerves parallel, usually
prominent.
Usually tall aquatic or marsh grasses, with flat blades, closed or
partly closed sheaths, and open or contracted panicles. Species about
35, in the temperate regions of both hemispheres; 16 species in the
United States.
Type species : Poa aquatica L.
Panicularia Heister ; Fabr., Enum. PI. Hort. Helmst., ed. 2, 373. 1763. The
genus is based on the species that Linnaeus named Poa aquatica.
Festucaria Heister; Fabr., Enum. PI. Hort. Helmst., ed. 2, 374. The
genus is based on the species that Linnaeus named Festuca fluitans.
Glyceria R. Br., Prodr. Fl. Nov. Holl. 179. 1810. Based on Festuca fluitans L.
Nevroloma Raf., Journ. de Phys. 89: 106. 1819. "Type, le Briza canadensis
de Michaux." This is Panicularia canadensis.
Our species are divided into two rather well marked groups. One
group, consisting of five species, has linear spikelets usually as much
as 1 cm. long. These species are represented by Panicularia fluitans,
the type of Festucaria and Glyceria. The group to which P. aquatica
belongs has ovate or oblong spikelets usually not over 5 mm. long.
The commonest species is Panicularia nervata (Willd.) Kuntze
(fig. 8), with small prominently 7-nerved spikelets in open panicles.
Panicularia canadensis (Michx.) Kuntze has larger less prominently
GENERA OF GRASSES OF THE UNITED STATES.
35
FIG. 8. Manna grass, Panicularia nervata. Plant, x J ; spikelet and floret, X 5.
36 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
nerved spikelets. Panicularia grandis (S. Wats.) Nash has very large
panicles of oblong spikelets, the lemmas prominently 7-nerved. Pani-
cula?*ia pauciftora (Presl) Kuntze, found in the western mountains,
has 5-nerved lemmas and rather small panicles.
The species are sometimes called manna grass and fowl meadow
grass. They are all excellent forage grasses, but usually form no
very important part of the grazing because they are limited to
swampy regions. Hydrocyanic acid has been found in Pq$4cularia
nervata, and some cases of cattle poisoning have been ascribed to it. 1
5. PLEUROPOGON R. Br.
Spikelets several to many flowered, linear, the rachilla disarticu-
lating above the glumes and between the florets; glumes unequal,
membranaceous or subhyaline, scarious at the somewhat lacerate tip,
the first 1-nerved, the second obscurely 3-nerved; lemmas membra-
naceous, 7-nerved, with a round indurate callus at base, the apex en-
tire or 2-toothed, the midnerve extending into a short mucro or into
an awn ; palea 2-keeled, the keels winged on the lower half.
Soft annuals or perennials, with flat blades and loose racemes of
rather large spikelets. Species three, one in the arctic region and
two on the Pacific coast of the United States.
Type species : Plctiropogon sabinii R. Br.
Pleuropogon R. Br., Suppl. App. Parry's Voy. 189, pi. D. 1823. A single
species, described and figured.
Lophochlaena Nees, in Taylor, Ann. Nat. Hist. 1: 283. 1838. Type L. cali-
fornica, the only species described.
Our species are found in bogs and wet meadows. One, Pleu-
ropogon calif omicus (Nees) Benth. (fig. 9), an annual with ascending
spikelets, is confined to California. The other, P. refractus (Gray)
Benth., a perennial with drooping spikelets, is found from northern
California to Washington. They are palatable grasses, but occur too
infrequently to be of economic value.
6. PUCCINELLIA Parl.
Spikelets several-flowered, usually terete or only slightly flattened,
the rachilla disarticulating above the glumes and between the florets ;
glumes unequal, shorter than the first lemma, obtuse or acute, rather
firm, often scarious at the tip, the first 1-nerved or sometimes
3-nerved, the second 3-nerved; lemmas usually firm, rounded on the
back, obtuse or acute, rarely acuminate, usually scarious and often
erose at the tip, glabrous or puberulent toward the base, 5-nerved,
the nerves parallel, obscure or indistinct, rarely rather prominent;
palea about as long as the lemma or somewhat shorter.
Annual, or usually perennial, low pale smooth cespitose grasses,
with narrow or open panicles. Species about 25, mostly along coasts
1 Alsberg and Black. Journ. Biol. Chcm. 21 : 601. 1915.
GENERA OF GRASSES OF THE UNITED STATES. 37
Fie. V.Pleuropogon caMfornicus. Plant, X i; spikelet, X 3; floret, X 5.
38 BULLETIN 772, IT. S. DEPARTMENT OF AGRICULTURE.
and on interior alkali soil of the cool and arctic regions of the
Northern Hemisphere; about 12 species in the United States, on
the Atlantic coast south to Delaware, on the Pacific coast south to
Point Beyes, and in the western interior south to New Mexico.
Type species: Poa distans L.
Puccinellia Parl., Fl. Ital. 1: 366. 1848. Parlntore describes 4 species, P.
distans (L.) Parl., P. festvcaeformis (Host) Parl., P. gussonii Parl., and P.
maritima (Huds.) Parl. The first is selected as the type.
Atropis Rupr., in Griseb. in Ledeb. Fl. Ross. 4: 388. 1853. Based upon Poa,
section Atropis Rupr., 1 of which the type and only species is Poa distans L.
Puccinellia differs from Poa in the rounded lemmas with indistinct
and parallel nerves. The species are mostly confined to the brackish
marshes of the coast. One species, Puccinellia nuttalliana (Schult,")
Hitchc. (P. airoides (Nutt.) Wats, and Coult.) (fig. 10), is common
in alkaline soils of the interior from Minnesota to Washington and
south to New Mexico. This species furnishes considerable forage
where it is common.
7. FLTJMINEA Fries.
(Scolochloa Link.)
Spikelets 3 to 4 flowered, the rachilla disarticulating above the
glumes and between the florets; glumes nearly equal, somewhat scari-
ous and lacerate at summit, the first 3-nerved, the second 5-nerved,
about as long as the first lemma ; lemmas firm, rounded on the back,
villous on the callus, 7-nerved, the nerves rather faint and unequal,
extending into a scarious lacerate apex; palea narrow, flat, about
as long as the lemma.
Tall perennials, with succulent rhizomes, flat blades, and spread-
ing panicles. Species two, one in eastern Siberia, the other in north-
ern Eurasia and northern North America, extending south to Iowa.
Type species : Festuca borcalis Mert. and Koch.
Scolochloa Link, Hort. Berol. 1: 136, 1827, not Scolochloa Mert. and Koch.
1823. Based on Arundo festucacea Willd. (Scolochloa festucacea Link), the
only species described. Scolochloa Mert. and Koch is based on Arundo dona.r L.
Fluminea Fries, Summa Veg. Scand. 247. 1846. Based on Festuca boreal IK.
A single species is included, its name being given as " Festuca boreulis
or Fluminea arundinucea" This is the same as Scolochloa festucacea.
Our single species, Fluminea festucacea (Willd.) Hitchc. (Arundo
festucacea Willd., Graphephorum festucaceum, Gray, ScoloMoa fes-
tucacea (Willd.) Link) (fig. 11), is a marsh grass found from Iowa
and Minnesota northward. It has some value for forage and is often
a constituent of marsh hay.
8. POA L., the bluegrasses.
Spikelets 2 to several flowered, the rachilla disarticulating above
the glumes and between the florets, the uppermost floret reduced or
rudimentary; glumes acute, keeled, somewhat unequal, the first
iBeitr. Pflanzenk. Russ. Reich. 2: 81. 1845 (Fl. Samoj. Cis.).
GENERA OF GRASSES OF THE UNITED STATES. 39
FIG. W.Puccinellia nuttalliana. Plant, X i ; spikelet and floret, X 5.
40 BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE.
FIG. ll.Fluminea festucacea. Plant, X i ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 41
1-nerved, the second usually 3-nerved ; lemmas somewhat keeled, acute
or acutish, awnless, membranaceous ? often somewhat scarious at the
tip, 5-nerved, the nerves sometimes pubescent.
Annual, or usually perennial, species of low or rather tall grasses,
with spikelets in open or contracted panicles, the narrow blades
flat or folded, ending in a navicular point. Species probably over
200, in the temperate and cool regions ; about 90 in the United States,
being especially numerous in the western mountains.
Type species : Poa pratensi* L.
Poa L., Sp. PI. 67, 1753; Gen. PI., ed. 5, 31. 1754. Linnaeus describes 17
species, 8 of which are still retained in the genus. Poa pratensis is chosen as the
type because it is an important economic species and because it is among the
species described under Poa in the Flora Lapponica. The first of the original
species, /'. <H] mi lira, is now referred to Panicularia ; P. flava to Triodia ; P. pilosa,
P. amaMUs, P. eragrostis, P. capillaris, and P. tenella to Eragrostis; P. mala-
barica to (Vnlothecn ; 7*. cHinensis to Leptochloa.
Paneion Lunell, Amer. Midi. Nat. 4 : 221. 1915. Proposed for Poa L., the word
poa being a Greek common noun, meaning herb, the author regarding it "unfit
as [a] generic name."
The base of the lemma sometimes bears a tuft of loose cottony hairs.
A group of western species, including Poa scabrella, (Thurb.) Benth.
of California (fig. 12), P. nevadensis Yasey of the Great Basin, and
P. sandberyii Vasey of the northern Rocky Mountain region, have
narrow, nearly terete spikelets, in narrow panicles, the lemmas
rounded on the back, glabrous, scabrous or minutely pubescent below.
Several species, such as mutton grass (P. fendleriana (Steud.) Vasey)
and its allies, P. douglasii Nees, and P. arachnifera Torr., are
dioacious. A few species, such as P. annua L., P. ~bigelovii Vasey and
Scribn. of Arizona, P. howellii Vasey and Scribn., and P. bolanderi
Vasey of California, are annual. Some of the perennial species,
such as P. scabrella, are bunch grasses, and some like P. pratensis and
P. compressa produce creeping rhizomes. Poa macrantha Vasey, a
dioacious sand-dune grass of Oregon, has spikelets as much as half
an inch long.
The bluegrasses are of great importance because of their forage
value, some species being cultivated for pasture and others forming
a large part of the forage on the mountain meadows of the West.
The most important species of the genus is Poa pratensis L. (PL
III ; fig. 13) commonly known as Kentucky bluegrass, or simply blue-
grass. This is a smooth perennial, with creeping rhizomes, erect
culms 1 to 3 feet high, soft flat or folded blades and open pyramidal
panicles 2 to 4 inches long, the lower branches in a whorl of usually 5,
the spikelets mostly 4 to 6 flowered, the florets cobwebby at base, the
keel and marginal nerves villous. Bluegrass is a native of Europe,
but is widely naturalized in the cooler parts of this country and is
cultivated for pasture and for lawns. It is the standard pasture grass
in the humid regions of the United States where the soil contains
plenty of lime.
42 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 12. Poo, scabrella. Plant, X \ ; spikelet and floret, x 5.
Bui. 772, U. S. Dept. of Agriculture.
PLATE III.
KENTUCKY BLUEGRASS (POA PRATENSIS).
Bui. 772, U. S. Dept. of Agriculture.
PLATE IV.
CANADA BLUEGRASS (POA COMPRESSA) IN FLOWER.
Bui. 772, U. S. Dept. of Agriculture.
PLATE V.
ANNUAL BLUEGRASS (PDA ANNUA).
Bui. 772, U. S. Dept. of Agriculture.
PLATE VI.
"
*
GENERA OF GRASSES OF THE UNITED STATES. 43
FlG !3 Bluegrass, Poa pratensis. Plant, X I ; spikelet and floret, X 5.
44 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
The name Kentucky bluegrass has been used because in Kentucky
the bluegrass pastures have been a prominent feature of the agricul-
ture of the State. In the northern portion of its range it is usually
called June-grass. Bluegrass flourishes as far west as eastern Ne-
braska and as far south as Virginia and in the mountains to northern
Alabama. In the valleys of the western mountains and in the humid
region of the Pacific coast, from northern California to British
Columbia, bluegrass is the common pasture grass. In the regions
where bluegrass is used for pasture it is the standard lawn grass.
By liming the soil and by artificial watering bluegrass may be grown
for lawns beyond the limits outlined above, but it can not be made
to thrive in the warmer parts of the Southern States or in the arid
regions of the Southwest.
Poa compressa L. (PL IV), cultivated under the name of Canada
bluegrass, is of some commercial importance, being grown in the
region that is adapted to the growth of Kentucky bluegrass, but it
is used chiefly on sterile sandy or clay soils where the latter species
does not thrive. Canada bluegrass differs from Kentucky bluegrass
in its blue-green color, distinctly compressed stems, and narrow less-
branched panicles. It produces abundant rhizomes that throw up
numerous scattered stems, mostly 6 to 15 inches tall, these being
usually solitary rather than tufted. On account of its wiry, com-
pressed stems it is called in some localities wire-grass and flat-stem.
Two other species of Poa occasionally grown but of little agricul-
tural importance are Poa trivialis L., rough-stalked meadow grass, a
species lacking rhizomes, but resembling P. pratensis in its panicle,
distinguished easily by its backwardly roughened sheaths; and Poa
palustris L. (P. triflora Gilib., P. serotina Ehrh.) known to seedsmen
as fowl meadow grass, a smooth, rather tall, tufted grass, differing
from bluegrass in the absence of rhizomes, in the larger more open
panicle, and in the smaller, 2 to 4 flowered spikelets.
Poa arachnifera Torr., Texas bluegrass, has been used in some of the
Southern States as a winter pasture grass and as a lawn grass. It is
an erect dioecious grass, 1 to 2 feet high, with strong rhizomes and
narrow panicles, 2 to 4 inches long, the staminate spikelets glabrous,
the pistillate spikelets with a copious tuft of woolly hairs at the base
of the florets. Texas bluegrass is a native of Oklahoma and Texas.
Poa annua L., annual bluegrass (PI. V), is a low, soft, light-green,
annual grass that is frequently found as a weed in lawns and gardens.
It thrives in the spring or even in the winter in southerly regions,
forming fine light-green patches, which die out later in the season,
leaving unsightly spots. Poa annua is a native of Europe, but is
widely introduced in America.
Several species are important range grasses. Malpais bluegrass
(Poa scabrella], a bunch grass, with slightly roughened sheaths and
GENERA OF GRASSES OF THE UNITED STATES. 45
narrow panicles of cylindric spikelets, the lemmas pubescent below, is
common at lower altitudes in California. Mutton grass (P. fendleri-
ana) is important in the Southwest. Little bluegrass (P. sand-
bergii), differing from malpais bluegrass in having smooth sheaths, is
common at medium altitudes (2,000 to 8,000 feet) throughout the
Northwest.
9. BRIZA L., the quaking grasses.
Spikelets several-flowered, broad, often cordate, the florets crowded
and spreading^ horizontally, the rachifla glabrous, disarticulating
above the glumes and between the florets, the uppermost floret re-
duced; glumes about equal, broad, papery-chartaceous, with scarious
margins; lemmas papery, broad, with scarious, spreading margins,
cordate at base, several-nerved, the nerves often obscure, the apex
in our species obtuse or acutish ; palea much shorter than the lemma.
Annual or perennial, low grasses, with erect culms, flat blades, and
usually open, showy panicles, the pedicels in our species capillary,
allowing the spikelets to vibrate in the wind. Species about 20, the
greater number South American. The three species found in the
United States are introductions from Europe and occur here as
occasional weeds in waste places.
Type species : Briza media L.
Briza L., Sp. PI. 70, 1753; Gen. PI., ed. 5, 32. 1754. Linnaeus describes 4
species, B. minor, B. media, B. maxima, and B. eragrostis. The first three were
familiar to Linnaeus as cultivated plants in the Hortus Cliffortianus, and the
second, which is selected as the type species, was described in his flora of Swe-
den. The first three species are now retained in Briza, the last is referred to
Eragrostis.
Of the three species found in this country, one, Briza media (fig.
14) , is perennial, and two, B. minor and B. maxima, are annual. The
spikelets of B. maxima, a species sometimes cultivated for ornament
under the name quaking grass, are large and showy, half an inch long,
drooping on slender pedicels. Briza minor, with smaller upright
spikelets, is rather common on the Pacific coast.
10. ERAGROSTIS Host.
Spikelets few to many flowered, the florets usually closely imbri-
cate, the rachilla disarticulating above the glumes and between the
florets, or continuous, the lemmas deciduous, the paleas persistent;
glumes somewhat unequal, shorter than the first lemma, acute or
acuminate, 1-nerved, or the second rarely 3-nerved; lemmas acute
or acuminate, keeled or rounded on the back, 3-nerved, the nerves
usually prominent; palea 2-nerved, the keels sometimes ciliate.
Annual or perennial grasses of various habit, the inflorescence an
open or contracted panicle. Species more than 100, tropical and tem-
perate regions ; 33 species in the United States, in all except the cool
or mountain regions.
46
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Type species : Brisa eragrostis L.
Eragrostis Host, Gram. Austr. 4: 14, pi. 24. 1809. One species is described,
but no generic description is given. The genus Eragrostis was first diagnosed
by Beauvois, 1 the type being
Eragrostis eragrostis, based on
Poa eragrostis L.
Erochloe Raf., Neogenyt. 4,
1825; Bull. Bot. Seringe 1: 221.
1830. Rafinesque first proposed
the name in 1825 but mentioned
no species. In 1830 he gives the
name to " Poa spectabilis sen
amabilis," (Eragrostis pectina-
cca and E. amabilis, respec-
tively, not the same species, as
Rafinesque implies).
Acamptoclados Nash, in Small,
Fl. Southeast. U. S. 139. 1903.
The type, indicated on page 1327,
is Eragrostis sessilispica Buckl.,
the only species described. The
genus is placed in Chloridese on
account of the sessile spikelets
distant along the panicle
branches.
Neeragrostis Bush, Trans.
Acad. St. Louis 13: 178. 1903.
The type species is indicated,
Poa iccigeltiana Reichenb. The
genus includes also 2V. Jiypnoides
( Eragros Us liypnoides ) .
Erosion Lunell, Amer. Midi.
Nat. 4: 221. 1915. Proposed for
" Eragrostis Beauv. . . . The
name to be avoided, as built on
another grass name."
FIG. 14. Quaking grass, Briza media. Plant, X \ ', spikelet and floret, X 5.
In many species the rachilla is continuous and does not disarticulate
as in most species of the tribe Festuceae. The grain is free and falls
with the lemma, leaving the palea upon the rachilla. To this group
1 Ess. Agrost. 70, pi. 14, f. 11. 1812.
GENERA. OF GRASSES OF THE UNITED STATES. 47
belong two common annual weeds, Eragrostis cilianensis (All.) Link
(E. mcgastachya (Koel.) Link, E. major Host), a disagreeable smell-
ing grass (fig. 15) with rather compact panicles of large spikelets
(3 mm. wide), the keels of the lemmas glandular dotted, and E. caro-
liniana (Spreng.) Scribn., with open panicles of small spikelets
(about 1.5 mm. wide).
Eragrostis pectinacea (Michx.) Nees (fig. 16) is a perennial with
handsome purple open'panicles, which at maturity separate from the
plant and tumble before the wind.
Eragrostis Jiypnoides (Lam.) B. S. P. is a spreading dioecious
annual found on sandy river banks. Eragrostis ciliaris (L.) Link
(fig. 17) and E. amabilis (L.) Wight and Am. (E. plwmosa Link)
are tropical annuals that extend into the Gulf States. They have
conspicuously ciliate paleas and disarticulating rachilla. A common
perennial species in sandy soil from Kansas to Texas is E. secundiflora
Presl (E. oxylepis Torr.) with contracted purple panicles, the rachilla
disarticulating and the florets falling separately.
In general, the species of Eragrostis have little forage value.
11. CATABROSA Beauv.
Spikelets mostly 2-flowered, the florets somewhat distant, the
rachilla disarticulating above the glumes and between the florets;
glumes unequal, shorter than the lower floret, flat, nerveless, irregu-
larly toothed at the broad truncate apex ; lemmas broad, prominently
3-nerved, the nerves parallel, the broad apex scarious; palea about
as long as the lemma, broad, scarious at the apex.
Aquatic perennials, with creeping bases, flat soft blades, and open
panicles. Species seven, in northern Eurasia and North America,
extending south to New Brunswick and Colorado ; one in Chile.
Type species : Aira aquatica L.
Gatabrosa Beauv., Ess. Agrost. 97, pi. 19, f. 8. 1812. The species illustrated
is C. aquaticd. Another name mentioned is a nomen nudum.
Catabrosa aquatica (L.) Beauv. (fig. 18) is found in mountain
meadows around springs and watercourses. It is an unimportant
forage grass.
12. MOLINIA Schrank.
Spikelets 2 to 4 flowered, the florets distant, the rachilla disarticu-
lating above the glumes, slender, prolonged beyond the upper floret,
and bearing a rudimentary floret; glumes somewhat unequal, acute,
shorter than the first lemma, 1-nerved ; lemmas membranaceous, nar-
rowed to an obtuse point, 3-nerved; palea bowed out below, equaling
or slightly exceeding the lemma.
48 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 15. Stink-grass, Eragrostis cittanensis. Plant, X I ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES.
49
FIG. 16. Love-grass, Eragrostis pectinacea. Plant x i ; spikelet and floret. X 5.
97769 19 Bull. 772 4
Slender tufted perennials, with flat blades and narrow, rather open
panicles. Species five, Europe and Asia; one sparingly introduced
in the United States.
FIG. 17. Eragrostis ciliaris. Plant, X I ; spikelet and floret, x 5.
Type species: Aira caerulea L.
Molinia Schrank, Baier. Fl. 1: 33(5. 1789. A single species described, J/.
varia, of which Aira caerulea L. is given as a synonym.
Molinia caerulea (L.) Moench (fig. 19) is introduced in a few local-
ities in the Eastern States from Xew England to Pennsylvania. In
Europe this is considered to be a good forage grass. A form with
striped leaves is cultivated for ornament, being used for borders.
GENERA OF GRASSES OF THE UNITED STATES.
51
13. DIAEINA Raf.
Spikelets few-flowered, the rachilla disarticulating above the
glumes and between the florets; glumes unequal, acute, shorter than
the lemmas, the first 1-nerved, the
second 3 to 5 nerved ; lemmas char-
taceous, pointed, 3-nerved, the
nerves converging in the point, the
upper floret reduced; palea char-
taceous, 2-nerved, obtuse, at ma-
turity the lemma and palea widely
spread by the large turgid beaked
caryopsis with hard shining peri-
carp.
Perennials, with slender rhi-
zomes, broadly linear, flat blades,
long-tapering below, and narrow,
few-flowered panicles. Species
two, one in eastern Asia and one
in the eastern United States.
Type species : Festuca diandra Michx.
Diarina Raf., Med. Rpos. 5: 352.
1808. Rafinesque bases a new genus on
FIG. 18. Catabrosa aquatica. Plant,
Festuca diandra Michx. (not Moench, 1794). He renames the species D. festu-
coides. Beauvois a spells the. name Diarrhena, crediting it to " S-hmal " [Rafin-
esque-Schmalz] and renames the single species D. americana.
i Ess. Agrost. 142, pi. 25, f. 1. 1812.
52
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Korycarpus Zea ; Lag., Gen. and Sp. Nov. 4. 1816. The only species described
is K. arundinaceus Zea, which is the same as Diarina festucoides. Lagasca cites
the reference "Ac. Matr. 1806," but
there seems to be no evidence that the
name Korycarpus was published earlier
than 1816.
Our single species, Diarina
f&stucoides Raf. (fig. 20), is
found in rich woods through
the eastern United States. It is
of little importance as a forage
grass.
14. DlSSANTHE-
LITJM Trin.
S p i kelets
mostly 2-flow-
ered, the ra-
chilla slender,
disarticulating
the
FIG. 19. Molinia caerulea. Plant, X \ ', spikelet and floret, X 5.
glumes and between the florets; glumes firm, nearly equal, acumi-
nate, much longer than the lower floret, mostly exceeding all
GENERA OF GRASSES OP THE UNITED STATES.
53
the florets, the first 1-nerved, the second 3-nerved; lemmas strongly
compressed, oval or elliptic, acute, awnless, 3-nerved, the lateral
nerves near the margin ; palea some-
what shorter than the lemma.
Annual or perennial grasses, with
narrow panicles. Species two, one
in Mexico and South America, the
other in California.
PIG. 20. Diarina festucoides. Plant, X \ ; spikelet and floret, X 5,
54
BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE.
Type species: Dissant helium supiuuni Trin.
Dissanthelium Trin., Linnsea 10: 305. 1836. One species described.
Stenochloa Nutt., Journ. Acad. Phita. II. 1: 189. 1848. One species described,
&. californica.
Our Calif ornian species, Dissantheliwm calif omicum (Nutt.)
Benth. (fig. 21), is an annual with flat blades and a narrow somewhat
open panicle. It is a rather
rare species found in
southern California and
the islands off the coast
and has no economic value.
The second species of
the genus is Dissanthelium
supinum Trin., a low
tufted perennial, with nar-
row, folded or convolute
blades and short, densely
flowered panicles. This is
found on alpine summits
in Mexico, Bolivia, and
Peru. It has been called
Deschampsia matthewsii
Ball and Dissanthelium
sclerochloides Fourn.
15. REDFIELDIA Vasey.
Spikelets compressed,
few-flowered, mostly 3 or
4 flowered, the rachilla
disarticulating above the
glumes and between the
florets; glumes somewhat
unequal, 1 -nerved, acumi-
nate; lemma chartaceous,
3-nerved, the nerves paral-
lel, densely villous at base ;
pa lea as long as the
lemma; grain free.
A rather tall perennial,
with rhizomes and a large
panicle with diffuse capil-
lary branches. Species
One 5 Sand hills f the
Great Plains.
FIG. 21.
flfaaantoe.Hum californium. Plant, X ft
spikelet and floret, X 5.
Type species: Graphephorum flexuosum Thurb.
Redfieldia Vasey, Bull. Torrey Club 14: 133. 1887.
R. flexuosa (Thurb.) Vasey.
One species described,
GENERA OF GRASSES OF THE UNITED STATES.
55
FIG. 22. Redfieldia ftexuosa. Plant, X I ; spikelet and floret, X 5.
Redfieldia flexuosa (fig. 22) is a gregarious sand-hill grass, one
of the few species found growing in the drifting sand, which it tends
56 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
to hold in place with its numerous creeping rhizomes. The species
is found from South Dakota to Kansas. It has little value for
forage but much value as a sand binder.
16. MONANTHOCHLOE Engelm.
Plants dioecious; spike-lets 3 to 5 flowered, the uppermost florets
rudimentary, the rachilla disarticulating tardily in pistillate spike-
lets; glumes wanting; lemmas rounded on the back, convolute, nar-
rowed above, several-nerved, those of the pistillate spikelets like
the blades in texture; palea narrow, 2-nerved, in the pistillate spike-
lets convolute around the pistil, the rudimentary uppermost floret
inclosed between the keels of the floret next below.
A creeping wiry perennial, with clustered short subulate leaves, the
spikelets at the ends of the short branches only a little exceeding the
leaves. Species two, one on muddy shores of the ocean in tropical
America, one in Argentina.
Type species: Monanthochloe Httoralis Engelm.
Monanthochloe Engelm., Trans. Acad. St. Louis 1: 1436. 1859. Only one
species described.
M onanthocJiloe Httoralis (fig. 23) is found within our limits only
in southern Florida, southern Texas, and southern California, on
tidal flats, sometimes covering extensive areas. Owing to the incon-
spicuousness of the spikelets, the flowering stage can be determined
only on close examination. The species has no economic importance
except as it tends to convert mud flats into permanent soil.
The leaves next the spikelet are reduced, but always present a
short though well-marked blade or foliaceous tip with a distinct
ligule. The branches bearing the spikelets are short and clustered.
The uppermost leaf, the one nearest the spikelet, usually has no bud
or branch in its axil. The leaf next below bears a bud or short
branch and a well-developed prophyllum. The prophylla of
branches somewhat lower may be 'as large as the sheath of the leaf,
and the two nerves may extend into prominent foliaceous tips. As
the branch develops, the prophyllum usually splits down the middle
and the two halves stand one on each side. The uppermost leaf
sometimes has in its axil a thin membranaceous nerveless obtuse
bract which clasps the spikelets like a second (upper) glume, but
probably this is to be interpreted as a prophyllum, subtending a
branch which failed to develop.
17. DISTICHLIS Raf.
Plants dioecious; spikelets several to many flowered, the rachilla
of the pistillate spikelets disarticulating above the glumes and
between the florets; glumes unequal, broad, acute, keeled, mostly
GENERA OF GRASSES OF THE UNITED STATES.
57
3-nerved, the lateral nerves sometimes faint or obscured by stria-
tions and intermediate nerves; lemmas closely imbricate, firm, the
pistillate coriaceous, the margins bowed out near the base, acute or
acutish, 3-nerved, with several intermediate nerves or striations;
palea as long as the lemma or shorter, the pistillate coriaceous, in-
closing the grain.
58 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Low perennials, with extensively creeping scaly rhizomes, erect,
rather rigid stems, and short, dense, rather few-flowered panicles.
Species about six, in salt marshes of the coast and interior in America,
one extending to Australia ; three species in the United States, one
widely distributed and two confined to Texas and northern Mexico.
Type species : Uniola spicata L.
Distichlis Raf., Journ. de Phys. 89: 104. 1819. Distichlis maritima is indi-
cated as the type by Rafinesque, who Drives Uniola spicata L. as a synonym.
Brizopyrum Presl, Rel. Haenk. 1: 280. 1830. Presl describes five species, of
which the first two belong to Distichlis. None is figured. The first species,
B. boreale (DistichUs. spicata), is selected as the type.
The common species, Distichlis spicata (L.) Greene (fig. 24), is
found along both coasts and in salt or alkali spots in the interior,
and extends southward to South America and to Australia. It is an
erect, gregarious grass usually not more than a foot high, with pale
spikelets, the staminate having a softer texture than the pistillate.
The common name is salt or alkali grass, though these names are some-
times applied to other species. In general it has little value for
forage but in the interior basins, such as the vicinity of Salt Lake, it
is utilized for grazing when better grasses are not available. The
large amount of salt or alkali may cause digestive disturbances.
This species is variable, and two forms have been distinguished as
species, D. stricta (Torr.) Ryclb. and D. dentata Rydb., both from
the Western States.
The two species of the Southwest are not well known. Distichlis
texana (Yasey) Scribn., a larger grass than D. spicata, with less
compressed spikelets and a long, narrow, loose panicle, is found from
Texas to Durango. Distichlis multinervosa (Yasey) Piper is an
anomalous species from western Texas known only from the type
collection. It differs in having a villous rachilla and 7-nerved mem-
branaceous lemmas, rounded on the back and villous on the lower
part, and in the 2-lobed palea.
18. UNIOLA L.
Spikelets 3 to many flowered, the lower one to four lemmas empty,
the rachilla disarticulating above the glumes and between the florets ;
glumes compressed-keeled, rigid, usually narrow, nerved, acute or
acuminate, or rarely mucronate ; lemmas compressed, sometimes con-
spicuously flattened, chartaceous, many-nerved, the nerves some-
times obscure, acute or acuminate, the empty ones at the base usually
successively smaller, the uppermost usually reduced; palea rigid,
sometimes bowed out in the winged keels.
Perennial, rather tall, erect grasses, with flat or sometimes convo-
lute blades and narrow or open panicles of compressed, sometimes
very broad and flat spikelets. Species nine, all North American,
GENERA OF GRASSES OF THE UNITED STATES. 59
six being represented in the United States, these inhabiting the
Southeastern States, some species extending as far north as Long
Island and as far west as Kansas and Texas.
FIG. 24. Salt-grass, Distichlis spicata. Staminate plant and a pistillate panicle, X
pistillate spikelet and floret, X 5.
Type species: Uniola paniculata L.
Uniola L., Sp. PI. 71, 1753 ; Gen. PL, ed. 5, 32. 1754. Linnreus describes two
species, U. paniculata and U. spicata. The first species is selected as the type.
The second is now referred to Distichlis.
60 BULLETIN 772, IT. S. DEPARTMENT OF AGRICULTURE.
Trisiola Raf., Fl. Ludov. 144. 1817. A single species, T. paniculata, based
on Uniola paniculata L., is included.
Nevroctola Raf., Neogenyt. 4. 1825. "Type Uniola maritima or paniculata."
Uniola maritima Michx. is U. paniculata L.
Chasmanthium Link, Hort. Berol. 1 : 159. 1829. A single species, C. gracile,
based on Uniola gracilis Michx., is included. This is* the .same as L'. hu-a (L.)
B. S. P.
Uniola paniculata, seaside oats, common on the coastal sand dunes
from Virginia to Texas, is a stout, pale grass, with extensively creep-
ing rhizomes, long-attenuate, firm blades, and large, drooping, heavy,
rather compact panicles of large, flat, stramineous spikelets. It is an
excellent sand binder. Uniola latifolici Michx. (PI. VI; fig. 25) is
a woodland grass with broad flat blades and handsome, open, droop-
ing, rather few-flowered panicles of large, very flat green spikelets.
The species is worthy of use in landscape gardening. This and the
remaining species of Uniola are of minor importance as forage
grasses, as they are not sufficiently abundant. The seeds of U. pal-
meri Vasey are used for food by the Cocopa Indians.
19. ARUNDO L.
Spikelets several-flowered, the florets successively smaller, the
summits of all about equal, the rachilla glabrous, disarticulating
above the glumes and between the florets ; glumes somewhat unequal,
membranaceous, 3-nerved, narrow, tapering into a slender point,
about as long as the spikelet; lemmas thin, 3-nerved, densely long-
pilose, gradually narrowed at the summit, the nerves ending in
slender teeth, the middle one longer, extending into a straight awn.
Tall perennial reeds, with broad linear blades and large plumelike
terminal panicles. Species about six, in the warmer parts of the
Old World ; one introduced in America.
Type species: Arundo donax L.
Arundo L., Sp. PI. 81, 1753 ; Gen. PI., ed. 5, 35. 1754. Linmeus describes six
C) represents the spikelets of Arundo donax, which is fully described on page
Genera Plantarum is " Scheuch. 3: 14, 3." Scheuchzer's figure 14 (A, B, and
C) represents the spikelets of Arundo donax, which is fully described on page
159 of Scheuchzer's work, Agrostographia. Hence, Arundo donax, the second
species described by Linnreus, is the type species of the genus. The other
original species are now referred as follows : A. bambos to Bambos, A. phrag-
mites to Phragmites, A. epificjos and A. calamoffrostis to Calamagrostis, .1.
arenaria to Ammophila.
Armulo donax, the giant reed (PI. VII; fig. 26), is cultivated as an
ornamental grass for lawn groups or borders. In tropical America
it is frequently used for hedges, and the stems are utilized for a
variety of purposes, such as the making of lattices in the construction
of huts. The giant reed has become naturalized in the Southwestern
States and sometimes forms a dense growth along irrigation ditches.
There is a cultivated ornamental variety with white-striped blades
(A. donax versicolor (Mill.) Kunth) . This was mentioned in Miller's
Gardener's Dictionarv in 1768 as Arundo versicolor.
Bui. 772, U. S. Dept. of Agriculture
PLATE VII,
GIANT REED (ARUNDO DONAX). CULTIVATED FOR ORNAMENT.
Bui. 772, U. S. Dept. of Agriculture.
PLATE VIM,
ORCHARD GRASS (DACTYLIS GLOMERATA) IN FLOWER.
GENERA OF GRASSES OF THE UNITED STATES.
61
FIG. 25. Uniola latifolia. Plant, X i ; spikelet and floret, X 3.
62 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 26. Giant reed, Arundo donax. Rhizome, leaves, and panicle, X J ; spikelet and
floret, X 3.
GENERA OF GRASSES OF THE UNITED STATES. 63
The giant reed is one of the largest of the herbaceous grasses, its
stem being as much as 20 feet tall. Ordinarily it grows in cultiva-
tion to a height of 6 to 10 feet. The rhizome is thick and knotty.
The blades are flat, 2 to 3 inches broad (smaller on the branches),
and distributed rather equally along the culm, the distichous ar-
rangement being conspicuous. The handsome feathery panicle is 1
to 2 feet long, the spikelets being about one-half inch long. In
the Southwest this is sometimes called by the Mexican name carrizo.
The stems of the giant reed are used for making clarionet and organ-
pipe reeds.
Two large cultivated grasses or reeds allied to Arundo are Gyne-
rium and Cortaderia.
Gynerium Humb. and Bonpl., PI. Aequin. 2: 105, pi. 115. 1809.
The single species described and figured is G. saccharoides Humb.
and Bonpl. This species, now called G. sagittatum (Aubl.) Beauv.,
is a giant dioecious grass as much as 30 or 40 feet tall, with culms
clothed below with old sheaths from which the blades have fallen,
sharply serrulate blades, commonly 6 feet long and about 2 inches
wide (forming a great fan-shaped summit to the sterile culms), and
pale, plumy, densely flowered panicles 3 or more feet long, the main
axis erect, the branches drooping; spikelets several-flowered, the
pistillate with long-attenuate glumes and smaller long-silky lemmas,
the staminate with shorter glumes and glabrous lemmas. This grass,
found along streams in tropical America, is cultivated occasionally
in greenhouses under the name of uva grass.
Cortaderia Stapf, Gard. Chron. III. 22: 396. 1897. Stapf in-
cludes five species in the genus, the first of which is C. argentea.
The genus is technically designated, on the page indicated in the
citation, but on a preceding page (p. 378) he says, "Taking Gyne-
rium argenteum as representative of the Cortaderas, . . .". Hence
Gynerium argenteum is selected as the type. This species, called
C. argentea (Nees) Stapf, is an erect dioecious perennial reed, grow-
ing in large bunches, with numerous long, narrow, basal blades, very
rough on the margins, and stout flowering culms 6 to 10 feet high,
with beautiful feathery, silvery white or pink panicles or plumes 1 to
3 feet long; spikelets 2 to 3 flowered, the pistillate silky with long
hairs, the staminate naked; glumes white and papery, long and
slender; lemmas bearing a long slender awn. This grass, called
pampas grass, is a native of Argentina. It is cultivated as a lawn
ornamental, being hardy in the warmer parts of the United States.
Pampas grass is cultivated commercially in southern California for
the plumes, which are used for decorative purposes. The plants
grow here to enormous size, as much as 20 feet in height.
64 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
20. PHRAGMITES Adans., the reeds.
Spikelets several-flowered, the rachilla clothed with long silky hairs,
disarticulating above the glumes and at the base of each joint between
the florets, the lowest floret staminate or neuter ; glumes 3-nerved, or
the upper 5-nerved, lanceolate, acute, unequal, the first about half
as long as the upper, the second shorter than the florets; lemmas
narrow, long-acuminate, glabrous, 3-nerved, the florets successively
smaller, the summits of all about equal ; palea much shorter than the
lemma.
Perennial reeds, with broad, flat linear blades and large terminal
panicles. Species three, one in Asia, one in Argentina, and one cos-
mopolitan.
Type species: Arundo phragmites L.
Phragmites Adans., Fam. PI. 2: 34, 559. 1763. Adanson cites "Arundo
Scheuz. 161," which Linnasus also cites under Arundo phragmites. Adanson
cites besides four other pre-Linnsean references, two of them queried. The other
two, which may refer to sugar cane or to sorghum, are to be excluded because
the few generic characters given, especially that the spikelets have several per-
fect flowers, do not at all apply to them, but do apply to Arundo phragmites.
Trinius * publishes Phragmites as a new genus based on Arundo phragmites L.,
changing the specific name to P. communis.
Trichoon Roth, Archiv Bot. Roemer I 3 : 37. 1798. Based on Arundo karka
Retz., an East Indian species of Phragmites.
Miphragtes Nieuwl., Amer. Midi. Nat. 3: 332. 1914. The name suggested for
Phragmites Trin. not Phragmites Adans. in case Trichoon Roth and Oxyanthe
Steud., to each of which Nieuwland transfers the specific name " Phragmites,"
should not "be applicable."
Our single species Phragmites communis Trin. (P. phragmites (L.)
Karst.) (fig. 27) is a tall reed with creeping rhizomes, leaves about
an inch broad, and panicles commonly a foot long. It grows in
marshes, around springs, and along lakes and streams throughout the
United States. Besides the rhizomes it produces extensively creep-
ing leafy stolons. In the Southwest this species, in common with
Arundo donax, is called by the Mexican name carrizo and is used for
lattices in the construction of adobe huts. The stems were used by
the Indians for the shafts of arrows, and in Mexico and Arizona for
mats and screens.
21. DACTYLIS L.
Spikelets few-flowered, compressed, finally disarticulating between
the florets, nearly sessile in dense one-sided fascicles, these borne at
the ends of the few branches of a panicle ; glumes unequal, carinate,
acute, hispid-ciliate on the keel; lemmas compressed-keeled, mucro-
nate, 5-nerved, ciliate on the keel.
Perennials, with flat blades and fascicled spikelets. Species two
or three, in Eurasia ; one, Dactylis glomerata, a native of Europe, cul-
tivated and naturalized in the United States.
1 Fund. Agrost. 134. 1820.
GENERA OF GRASSES OF THE UNITED STATES.
65
FIG. 27. Reed, Phragmites communis. Rhizomes, leaves, and panicles, X $ ', spikelet
and floret, X 3.
97769 19 Bull. 772 5
66 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 28. Orchard grass, Dactylis glomerata. riant, X I ; spikelet and floret, X 5.
GENERA. OF GRASSES OF THE UNITED STATES.
67
Type species: Dactylis ylomerata L.
Dactylis L., Sp. PI. 71, 1753 ; Gen. PL, ed. 5, 32. 1754. Linnaeus describes two
species, D. cynosuroides from Virginia, and D. glomerata from Europe. The
latter species being described in his flora
of Sweden is chosen as the type.
Dactylis glomerata, orchard grass
(PL VIII; fig. 28), is a well-known
meadow and pasture grass, cultivated
in the humid region of the United
States. It is a rather coarse, erect,
perennial bunch-grass, soon forming
large tussocks, with culms 2 to 1
feet tall, flat blades as much as one-
third of an inch wide, panicles 3 to 8
inches long, with a few stiff branches,
spreading in flower, appressed in
fruit. In England this is called
cocksfoot grass. Orchard grass is
recommended for shaded situations,
as it withstands shade better than our
other meadow grasses.
22. CYNOSURUS L.
Spikelets of two kinds, sterile and
fertile together, the fertile sessile,
nearly covered by the short-pediceled
sterile one, these pairs imbricate in a
dense one-sided spikelike panicle;
sterile spikelets consisting of two
glumes and several narrow, acumi-
nate, 1-nerved lemmas on a continu-
ous rachilla; fertile spikelets 2 or 3
flowered, the glumes narrow, the
lemmas broader, rounded on the back,
awn-tipped, the rachilla disarticulat-
ing above the glumes.
Species four, in the Mediterranean
region ; one occasionally cultivated in
the United States and sparingly es-
caped into waste places.
Type species : Cynosurus cristatus L.
Cynosurus L., Sp. PI. 72, 1753; Gen. PI.,
ed. 5, 33. 1754. Linnaeus describes nine
species. The first species, C. cristatus, is
chosen as the type because it is an eco-
nomic species and is one of three species
described in his flora of Sweden. Of
the remaining Linnsean species, one, C. echinatus, is now retained in Cyno-
surus; (7. lima is referred to Wangenheimia ; C. durus, to Scleropoa ; C. coeru-
leus, to Sesleria; C. aegyptius, to Dactyloctenium ; C. indicus, to Eleusine; O.
paniceus, to Polypogon ; C. aureus, to Achyrodes.
FIG. 29. Crested dog's-tail grass,
Cynosurus cristatus. Plant, X i ;
fertile spikelet and floret, X 5.
68 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
The only species in the United States is Cynosurus cristatus L. (fig.
29), known as crested dog's-tail grass. This is occasionally sown in
mixtures for meadows, but has nothing especially to recommend it-
It is a tufted perennial 1 to 2 feet tall, the panicles 2 to 4 inches long.
23. ACHYRODES Boehmer.
(Lamarckia Moench.)
Spikelets of two kinds, in fascicles, the terminal one of each fas-
cicle fertile, the others sterile; fertile spikelet, with 1 perfect
floret, the rachilla produced beyond the floret, bearing a small awned
empty lemma or reduced to an awn; glumes narrow, acuminate or
short-awned, 1-nerved; lemma broader, raised on a slender stipe,
scarcely nerved, bearing just below the apex a delicate straight awn ;
sterile spikelets linear, 1 to 3 in each fascicle, consisting of 2
glumes similar to those of the fertile spikelet, and numerous distich-
ously imbricate, obtuse, awnless, empty lemmas.
A low, erect annual, with flat blades and oblong, one-sided, compact
panicles, the crowded fascicles drooping, the fertile being hidden, ex-
cept the awns, by the numerous sterile ones. Species one, a native of
southern Europe, naturalized in southern California.
Type species: Cynosurus aureus L.
Achyrodes Boehmer, in Ludw. Def. Gen. PI. 420. 3760. The genus is based on
a phrase name of Tournefort, which Linnreus cites under Cynosurus aureus L.
Lamarckia Moench, Meth. PI. 201. 1794. A single species is described, L.
aurea (Cynosurus aureus L.).
Chrysurus Pers., Syn. PI. 1: 80. 1805. A single species, C. cynosuroidcs,
based on Cynosurus aureus L., is included.
The single species, AcJiyrodes aureum (L.) Kuntze (fig. 30), is
abundantly naturalized in southern California. It is called golden-
top because of its beautiful golden yellow panicles.
24. MELICA L.
Spikelets 2 to several flowered, the rachilla disarticulating above
the glumes and between the florets, prolonged beyond the perfect
florets and bearing at the apex two or three gradually smaller empty
lemmas, convolute together or the upper inclosed in the lower;
glumes somewhat unequal, thin, often papery, scarious-margined,
obtuse or acute, sometimes nearly as long as the lower floret, 3 to 5
nerved, the nerves usually prominent ; lemmas convex, several-nerved,
membranaceous or rather firm, scarious-margined, sometimes con-
spicuously so, awnless or sometimes awned from between the teeth of
the bifid apex.
Bather tall perennials, with the base of the culm often swollen
into a corm, with closed sheaths, usually flat blades, narrow or some-
times open, usually simple panicles of relatively large spikelets.
Species about 60, in the cooler parts of both hemispheres; 18 in the
United States, mostly woodland grasses.
GENERA OF GRASSES OF THE UNITED STATES. 69
Type species: Melica nutans L.
Melica L., Sp. PI. 66, 1753; Gen. PL, ed. 5, 31. 1754. Linnreus describes three
species, M. ciliata, M. nutans, and M. altissima, all species of Eurasia and all
now retained in the genus Melica. In the Flora Lapponica, where the generic
name was first used, the only species described is referred by Linnaeus in the
Species Plantarum to M. nutans; hence this species is selected as the type.
Bromelica Farwell, Rhodora 21: 77. 1919. Based on Melica, section
Bromelica Thurb., of which the type is M. Itromoides Gray (M. yeyeri Munro).
l
FIG. 30. Golden-top, AcJiyrodes aureum. Plant, X \ ; fertile spikelet and floret, X 5.
In our eastern species, Melica mutica Walt. (fig. 31) and M. nitens
Nutt., the sterile lemmas form a rather prominent truncate or hood-
70 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 31. Melica mutica. Plant, X I ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 71
shaped body back of the upper floret, and the glumes and fertile
lemmas are conspicuously scarious. In many of the western species
the sterile lemmas are small and narrow, forming an inconspicuous
body at the top of the rachilla, and the glumes and fertile lemmas are
either broad or rather narrow with less conspicuous scarious margins.
In J/. imperfecta Trin., of California, there is but one fertile floret.
One group of species with narrow, scarcely flattened spikelets and
little-differentiated upper florets has been segregated as a section
under the name Bromelica. The awned species of the genus, M. aris-
tata Thurb. (fig. 32), M. smithii (Porter) Vasey, and M. purpu-
rascens (Torr.) Hitchc., belong to this group. The inflorescence of
Melica is usually narrow, a simple panicle or even a raceme, but in
M. smithii, M. geyeri Munro, and M. nitens it may be an open but
rather few-flowered panicle. The corms produced by many species
are characteristic and have suggested the name onion grass often
applied to them. The genus is distinguished from allied genera by
the scarious margins of the glumes and lemmas. The awned species
of the section Bromelica approach closely to Bromus.
The species of Melica, commonly called melic grasses, are in gen-
eral excellent forage grasses. They are, however, not gregarious,
and do not ordinarily furnish any large proportion of the forage of
the ranges. The two most important species on the ranges are M.
lella Piper and M. spectabilis Scribn. They have broad spikelets,
bulbous bases, and narrow panicles, the first with erect pedicels, the
second with slender recurved pedicels.
25. ANTHOCHLOA Nees.
Spikelets few-flowered, subsessile, on a simple axis and imbricate,
the rachilla disarticulating above the glumes and between the florets ;
glumes (in our species) wanting; lemmas thin-membranaceous, flabel-
liform, whitish, petallike, many nerved; palea narrower than the
lemma, hyaline.
Low annuals or perennials, with close, spikes. Species three ; two
in the Andes, one in California.
Type species : Anthochloa lepidiila Nees.
Anthochloa Nees; Meyen, Reise urn Erde 2: 14. 1835. One species men-
tioned. The description is meager and scarcely constitutes technical publica-
tion. It is as follows : " Wir sammelten hier ein sehr kleines aber ausserst
schones Gras, das die neue Gattung Anthochloa bildet und von Herrn Nees v.
Esenbeck Anthochloa lepickula genannt worden ist (Anthochloa genus proximum
Melicae, differt glumis brevioribus, valvula superior! quadrifida ! ) ." The genus
is first described by Endlicher 1 but no species is mentioned. Remy 2 describes
the genus and one species (A. rupestris).
Stapfia Davy, Erythea 6: 110, pi. 3, 1898, not Stapfia Chodat, 1897. One
species described, S. colusa-na.
Neostapfia Davy, Erythea 7 : 43. 1899. A new name for Stapfia Davy.
Davyella Hack., Oesterr. Bot. Zeitschr. 49 : 133. 1899. A new name proposed
for Stapfia Davy, not Chodat.
1 Gen. PI. 99. 1836. a Ann. Sci. Nat. Bot. III. 6:347. 1846.
72 BULLETIN 772, IT. S. DEPARTMENT OF AGRICULTURE.
FIG. 32. Melica aristata. Plant, X I ; spikelet and floret, X 5,
GENERA OF GRASSES OF THE UNITED STATES. 73
Our species, Anthochloa colwatw (Davy) Scribn. (fig. 33), is
known only from the type collection, from Colusa County, Calif. It
is an annual, with broad flat leaves with no distinction between
sheath and blade, and dense cylindric spikes, the upper part of the
axis bearing, instead of spikelets, lanceolate-linear empty bracts.
FIG. 33. Anthochloa colusana. Plant X ; spikelet and floret, X 5.
26. TRIODIA R. Br.
Spikelets several-flowered, the rachilla disarticulating above the
glumes and between the florets; glumes membranaceous, often thin,
nearly equal in length, the first sometimes narrower, 1 -nerved or the
second rarely 3 to 5 nerved, acute or acuminate; lemmas broad,
rounded on the back, the apex from minutely emarginate or toothed
to deeply and obtusely lobed, 3-nerved ; the lateral nerves near the
margins, the midnerve excurrent between the lobes as a minute point
or as a short awn, the lateral nerves often excurrent as minute points,
all the nerves pubescent below (subglabrous in one species), the lat-
eral ones sometimes conspicuously so throughout; palea broad, the
two nerves near the margin, sometimes villous.
Erect, tufted perennials, rarely rhizomatous or stoloniferous, the
blades usually flat, the inflorescence an open or contracted panicle,
or a cluster of few-flowered spikes interspersed with leaves. Species
about 25, mostly in America ; 15 species in the United States.
74 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Type species: Triodia pungcns R. Br.
Trioclia R. Br., Prodr. Fl. Nov. Holl. 1 : 182. 1810. Six species are described,
tlie first of which is selected as the type. In this the lemma is firm, rather ob-
scurely 3-nerved, villous along the lower half of the back and margins, 2-toothed
at the summit, the midnerve excurrent between the acute teeth as a short awn
as long as the teeth, the lateral nerves extending into the teeth.
Tricuspis Beauv., Ess. Agrost. 77, pi. 15, f. 10, 1812, not Tricuspis Pers., 1807.
The figured species is T. caroliniana, discussed in the following paragraph.
Tridens Roern. and Schult., Syst. Yeg. 2 : 34. 1817. Under the description of
the genus is a reference to a figure of Beauvois. 1 Beauvois describes the figure
(which represents Triodia flava) under the name Tricuspis caroliniana. Under
the description of the genus (p. 77) Beauvois mentions two species, Poa caerules-
fcns Michx. and Tricuspis novaeboracensis Beauv. Both are nomina nuda, the
first never having been published by Michaux, and Beauvois giving no descrip-
tion of the second. Roemer and Schultes on a later page (p. 599) describe the
single species referred to Tridens, under the name T. quinquefida, based upon
Poa quinquefida Pursh, which is Triodia flava.
Windsoria Nutt, Gen. PI. 1 : 70. 1818. Two species are described, W. poae-
formis Nutt., which is Triodia flava, and TV 7 . ambigita (Ell.) Nutt. The first is
selected as the type.
Rhombolytrum Link, Hort. Berol. 2 : 296. 1833. The single species described
is R. rhomboidea from Chile. Bentham and Hooker 2 state that two North Ameri-
can species, Triodia, albcscens and T. trin-errif/1 urn-is, are allied to this. Nash 3
recognizes the genus Rhombolytrnni and transfers to it Sieglingia albescens
(Vasey) Kuntze.
Erioneuron Nash, in Small, Fl. Southeast. U. S. 143. 1903. The type, Uralepis
pilosa, is indicated on page 1327 of the same work. Only one species included.
Dasyochloa Willd. ; Rydb., Colo. Agr. Exp. Sta. Bull. 100: 37. 1906. (Flora
of Colorado.) The name first appeared in Steudel's Nomenclator * as a synonym
of Uralepis (Uralepsis), where two species are listed, D. avenacea Willd. and D.
pulchella Willd., both being herbarium names. The type and only species men-
tioned is D. pulchella (H. B. K.) Willd.
Some authors have referred our species to Sieglingia Bernh. 5 The type of
Sieglingia is Festuca decumbens L. This species seems to represent a distinct
genus, differing in having 5 to several nerved lemmas. The single species, /S.
decumbens (L.) Bernh., a native of Europe, is found in Newfoundland, but does
not occur in the United States.
The species of Triodia are diverse in habit and in floral characters,
but it does not seem practicable to segregate any of them as distinct
genera. Triodia flava (the type of Tridens) and T. pulchella (the
type of Dasyochloa) represent the two extremes, but they are con-
nected by a series of intergrading species. The type species of
Triodia, T. pungens, of Australia, in the form of its spikelets, stands
about midway between our two extremes. Its spikelets, though less
pubescent, are much like those of T. avenacea, with the midnerve of
the lemma excurrent between the teeth, the lateral nerves not ex-
current but extending into the teeth. Triodia putchella H. B. K.
(fig. 34) differs in habit from all the other species. It sends
up from the basal cluster of leaves slender branches with
elongate internodes, which produce at the extremity a cluster
of short leaves and short, few-flowered spikes. Later from these
clusters are produced slender branches, which in their turn form
clusters of leaves and spikelets. The clusters bend to the ground and
take root, so that ultimately there is formed a colony of these clusters
1 Beauv. Ess. Agrost. pi. 15, f. 10. 1812. * Norn. Bot, ed. 2, 1: 484. 1840.
2 Gen. PI. 3: 1176. 1883. - 6 Syst. Verz. Pflanz. Erfurt. 40. 1800.
3 In Britton, Man. 129. 1901.
GENERA OF GRASSES OF THE UNITED STATES.
75
of leaves and spikelets connected by the slender internodes. This
species and two others, T. avenacea H. B. K. and T. nealleyi Vasey,
-*
agree in having deeply 2-lobed lemmas, the midnerve excurrent be-
tween the lobes as an awn. The last two species and T. pilosa ( Buckl. )
Merr. have short, spikelike panicles, but the last species differs in
76 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
having acuminate lemmas. These four species and T. mwtica (Torr.)
Scribn. agree in having woolly lemmas, the lower part of the three
nerves being long-villous, and in having paleas villous on the wings.
Tmodia rrmtica has a somewhat elongate panicle and differs in having
very obtuse, broad, sometimes minutely notched, awnless lemmas, the
lateral nerves disappearing before reaching the margin. The afore-
mentioned species might be set off under Erioneuron, but they would
not form a coherent group.
Triodia flava (L.) Hitchc. (Poa flava L.) (fig. 35) has an open,
elegantly drooping panicle of purple spikelets, the nerves of the
lemmas pubescent below, extending into 3 mucros. This is common
in autumn through the Eastern States in meadows and open wood-
land and is sometimes called purple-top. It exudes a sticky sub-
stance on the culm below the panicle and on the main branches of
the inflorescence, to which dirt adheres. One species, T. drum-
mondii Scribn. and Kearney, produces rhizomes.
Three species (besides T. mutica mentioned above) have a spike-
like panicle. These are T. aTbescens Vasey, with glabrous lemmas;
T. elongata (Buckl.) Scribn., with glumes nearly as long as the
spikelet; and T. stricta (Nutt.) Yasey, with shorter glumes but mu-
cronate lemmas. The other species have more or less open panicles.
In general the species of Triodia are of little importance agricul-
turally. Triodia pulchella is often abundant on the ranges, but is
not relished by stock, the little dry plants being seldom eaten.
27. TRIPLASIS Beauv.
Spikelets few-flowered, the florets remote, the rachilla slender,
terete, disarticulating above the glumes and between the florets;
glumes nearly equal, smooth, 1-nerved, acute; lemmas narrow,
3-nerved, 2-lobed, the nerves parallel, pubescent or villous, the lateral
pair near the margin, the midnerve excurrent as an awn, as long as
or longer than the lobes ; palea shorter than the lemma, 2-keeled, the
keels densely long-ciliate on the upper half.
Slender tufted annuals or perennials, with short blades, short, open,
few-flowered purple panicles terminating the culms, and cleistoga-
mous narrow panicles in the axils of the leaves. Species three ; south-
eastern United States.
Type species : Triplasis americana Beauv.
Triplasis Beauv., Ess. Agrost. 81, pi. 16, f. 10. 1812. The single species,
T. americana, is figured.
Uralepis Nutt., Gen. PL 62. 1818. Nuttall describes two species, U. purpurea,
based on Aira purpurea Walt. (Triplasis purjmrea (Walt.) Chapm.) and U.
aristulata, which is the same species. The first is selected as the type. The
name is spelled Uralepsis, but this is a typographical error. Nuttall states
that it is based on the Greek words oiira and lepis.
Diplocea Raf., Amer. Journ. Sci. 1 : 252. 1819. One species described, D. 6or-
bata, which is the same as Triplasis purpurea.
Merisachue Steud., Syn. PI. Glum. 1: 117. 1854. Contains one species,
M. drummondii Steud., Drummond 330, from Texas (Triplasis purpurea).
GENERA OF GRASSES OF THE UNITED STATES. 77
FIG. 35. Purple-top, Trwdia fla>va. Plant, X i ; spikelet and floret, X 5.
78 BULLETIN 772, JJ. S. DEPARTMENT OF AGRICULTURE.
The three species are found in sandy soil in the Eastern States,
Triplasis purpivrea (fig. 36) from Maine to Florida and from the
Great Lakes to Texas. Triplasis intermedia is confined to Florida ;
T. americana is found from North Carolina to Florida. All the spe-
cies, besides the small panicles of cleistogamous spikelets in the upper
sheaths, have additional cleistogamous spikelets, reduced to a single
large floret, at the bases of the lower sheaths. The culms break at
the nodes bearing these cleistogenes, the ripe seed remaining attached
to the internode. The species are of no importance except as they
tend to hold sandy soil.
For a revision of the species of Triplasis, see Nash, Bull. Torrey
Club 25:561-565. 1898.
28. BLEPHAKIDACHNE Hack.
Spikelets 4-flowered, the rachilla disarticulating above the glumes
but not between the florets; glumes nearly equal, about as long as
the spikelet, compressed, 1-nerved, thin, acuminate, smooth; lemmas
deeply 3-lobed, 3-nerved, the first and second sterile, containing a
palea but no flower, the third fertile, the fourth reduced to a 3-awned
rudiment.
Low annuals or perennials, with short, congested, few-flowered
panicles scarcely exserted from the subtending leaves. Species two ;
one in Argentina, one in Nevada.
Type species: Eremochloe kingii S. Wats.
Eremochloe S. Wats., in King, Geol. Expl. 40th Par. 382, pi. 40, 1871, not
Eremochloa Biise, 1854. Two species are described, one E. kingii from Nevada
and the other, in a footnote, E. bigelovii, from southern New Mexico. The two
specimens are to be referred to the same species.
Blepharidachne Hack., in Engl. and Prantl, Pflanzenf am. 2 2 : 126. 1887. In a
footnote the name Blepharidachne is substituted for Eremochloe S. Wats.,
because of the earlier Eremochloa Biise. The author of Blepharidachne is given
as " Hook.," a typographical error for Hack.
Blepharidachne Jcingii (S. Wats.) Hack. (fig. 37), found on the
plains and foothills of Nevada (and New Mexico according to
Watson), has been collected only a few times.
A second species, Blepharidachne benthamiana (Hack.) Hitchc.
(Munroa benthamiana Hack. 1 ) grows in dry regions of Argentina.
In habit it resembles our Munroa squarrosa, but in floral structure it
agrees with Blepharidachne, having two sterile florets, one fertile
floret, and a 3-awned rudiment.
29. OECTJTTIA Vasey.
Spikelets several-flowered, the upper florets reduced; rachilla per-
sistent, continuous, the florets falling away or tardily disarticulating ;
glumes nearly equal, shorter than the lemmas, broad, irregularly 2 to 5
1 In Kuntze, Rev. Gen. PI. 3 2 : 357. 1898.
GENERA OF GRASSES OF THE UNITED STATES.
79
r<
FIG. 36. Triplasis purpurea. Plant, X J ; spikelet, floret (above) showing beard on tbx
nerves of the palea and cleistogene (at left), a cleistogamous fertile 1-flowered spikelet
from the axil of a lower leaf, aJl X 5.
80
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
toothed, many-nerved, the nerves extending into the teeth; lemmas
firm, prominently 13 to 15 nerved, the broad summit with 5 long
FIG. 37. Blepharidachne kingii. Plant, X 1 ; spikelet and perfect floret, the latter
showing the rudiment behind the palea, X 5.
teeth or with numerous short teeth ; palea broad, 2-nerved, as long as
the lemma.
Low cespitose annuals, with short blades and terminal spikelike
racemes, the spikelets rel-
atively large, appressed,
the upper aggregate, the
lower more or less remote.
Species two ; California
and Lower California.
Type species: Orcuttia call-
f arnica Vasey.
Orcuttia Vasey, Bull. Tor-
rey Club 13 : 219, pi. 16. 1886.
The one species described was
collected by C. R. Orcutt at
San Quentin Bay, Lower Cali-
fornia.
Our species, both in
California, are Orcuttia
greenei Vasey, from Chico,
of which only the type
collection is known, and
0. calif omica (fig. 38),
has been collected
no. 8 a-o ra , io cau/orntca. Plant, x i; .pikelet
and floret, the latter without a joint of the at GrOOSe Valley, llielat-
rachilla, this not disarticulating, X 5. ter S p ec i es i s distinguished
by having 5-toothed lemmas; 0. greenei has truncate lemmas, the
nerves extending into short points.
GENERA OF GRASSES OF THE UNITED STATES. 81
30. SCLEROPOGON Philippi.
Plants dioecious. Staminate spikelets several-flowered, pale, the
rachilla not disarticulating; glumes about equal, a perceptible inter-
node between, membranaceous, long-acuminate, 1-nerved or obscurely
3-nerved, nearly as long as the first lemma; lemmas similar to the
glumes, somewhat distant on the rachilla, 3-nerved or obscurely 5-
nerved, the apex mucronate; palea obtuse, shorter than the lemma.
Pistillate spikelets several -flowered, the upper florets reduced to
awns, the rachilla disarticulating above the glumes but not separat-
ing between the florets or only tardily so; glumes acuminate, 3-
nerved, with a few fine additional nerves, the first about half as long
as the second ; lemmas narrow, 3-nerved, the nerves extending into 3
slender, scabrous, spreading awns, the florets falling together forming
a cylindric many-awned fruit, the lowest floret with a sharp-bearded
callus as in Aristida ; palea narrow, the two nerves near the margin,
produced into short awns.
A perennial stoloniferous grass, with short flexuous blades and
narrow few-flowered racemes or simple panicles, the staminate and
pistillate strikingly different in appearance. Species one; Chile to
southwestern United States.
Type species: Scleropogon brevifolius Philippi.
Scleropogon Philippi, Anal. Univ. Chile 36: 205. 1870. Only one species de-
scribed.
Lesourdia Fourn., Bull. Soc. Bot. France 2 7 : 102, pi. 3, 4. 1880. Two species
Are proposed, L. multlflora and L. kar wins ky ana, both referable to the same
species, Scleropogon brevifolius.
This species (fig. 39) is found on semiarid plains and open valley
lands from southern Colorado to Texas and Arizona and southward.
The mature pistillate spikelets break away and with their numer-
ous long spreading awns form " tumbleweeds " that are blown before
the wind. The pointed barbed callus readily penetrates clothing or
wool, the combined florets acting like the single floret of the long-
awned aristidas. As a forage grass, this is inferior to grama ; but on
overstocked ranges, where it tends to become established, it is use-
ful in preventing erosion. It is called burro grass.
31. COTTEA Kunth.
Spikelets several-flowered, the uppermost reduced, the rachilla dis-
articulating above the glumes and between the florets; glumes two,
about equal, nearly equaling the lower lemma, with several parallel
nerves ; lemmas rounded on the back, villous below, prominently 9 to 11
nerved, the nerves extending partly into awns of irregular size and
partly into awned teeth ; palea awnless, a little longer than the body
of the lemma.
97769 19 Bull. 772 6
82 BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE.
FIG. 39. Burro grass, Scleropogon brevifolius. Pistillate (left) and staminate plants,
X i ; pistillate spikelet, X 2 ; pistillate and staminate floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 83
An erect tufted branching perennial, with oblong open panicles.
Species one; western Texas to southern Arizona and southward to
Argentina.
Type 4 species: Cottcu pappophoroides Kunth.
Cottea Kunth, Rev. Gram. 1: 84. 1829. A single species mentioned, from
Peru.
This genus is allied to Pappophorum and very closely related to
Anthoschmidtia of Africa. It differs from the first in the several-
flowered spikelets that separate between the florets and in the awns
interspersed with awned teeth. Anthoschmidtia differs in having
glumes longer than the florets and in having lemmas with five awns
alternating with four lobes.
Cottea pappophoroides Kunth (fig. 40) is not abundant enough to
have agricultural importance in the United States. Cleistogenes are
produced in the lower sheaths. 1
32. PAPPOPHORUM Schreb.
Spikelets 2 to 5 flowered, the upper reduced, the rachilla disarticu-
lating above the glumes but not between the florets, the internodes
very short; glumes nearly equal, keeled, thin-membranaceous, as long
as or longer than the body of the florets, 1 to several nerved, acute;
lemmas rounded on the back, firm, obscurely many nerved, dissected
above into numerous spreading scabrous or plumose awns, the florets
falling together, the awns of all forming a pappuslike crown ; palea
as long as the body of the lemma, 2-nerved, the nerves near the
margin.
Erect, cespitose perennials, with narrow or spikelike tawny or
purplish panicles. Species 20, in the dry parts of the Old World, in
Australia, and from Texas to Argentina; 3 species in the United
States, from Texas to Arizona.
Type species: Pappophorum alopecuroideum Vahl.
Pappophorum Schreb. ; Vahl, Symb. Bot. 3 : 10. 1794. Only one species de-
scribed.
Enneapogon Desv. ; Beauv., Ess. Agrost. 81, pi. 16, f. 11. 1812. Beauvois men-
tions Enneapogon desvauxii, Pappophorum gracile, P. nigricans, P. pallidum,
and P. purpurascens. The first one, being figured, is selected as the type.
Polyrhaphis (Trin.) Lindl., Veg. Kingd. 115. 1847. Based on Pappophorum,
section Polyrhaphis Trin., under which a single species, P. alopecuroides Vahl,
is included.
Pappophorum bicolor Fourn., with purplish, rather loose panicles,
is found in southern and western Texas ; P. vaginatum Buckl. (fig. 41) ,
with pale, slender, spikelike panicles, and P. wrightii S. Wats. (fig.
42), with plumbeous short spikelike panicles and 9-nerved lemma, the
nerves extending into 9 equal plumose awns, are found from western
Texas to southern Arizona. Pappophorum wrightii produces cleis-
togamous spikelets in the lower sheaths. The cleistogenes are larger
than the normal florets, but the awns are almost wanting. As is the
1 Chase, Amer. Journ. Bot. 5 : 256. 1918.
84 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
PIG. 40. Cottea pappophoroides. Plant, X \ ; spikelet, floret, and cleistogene (left) from
axil of lower leaf, all X 5.
GENERA OF GRASSES OF THE UNITED STATES.
85
FIG. 41. Pappophorum vayinatum. Plant, X i ; spikelet and perfect floret, X 5.
86
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
case with other grasses producing cleistogenes in the lower sheaths,
the culms disarticulate at the lower nodes. Our species are of minor
FIG. 42. Pappophorum wriglitii. Plant, X \ ; spikelet, perfect floret, and cleistogene
(below) from axil of lower leaf, all X 5.
agricultural importance, the second and third sometimes constituting
a fair proportion of the forage on sterile hills.
GENERA OF GRASSES OF THE UNITED BTATES. 87
3. HORDEAE, BARLEY TRIBE.
33. AGBOPYBON Gaertn.
Spikelets several-flowered, solitary (or rarely in pairs), sessile,
placed flatwise at each joint of a continuous (rarely disarticulating)
rachis, the rachilla disarticulating above the glumes and between the
florets ; glumes two, equal, firm, several nerved, usually shorter than
the first lemma, acute or awned, rarely obtuse or notched; lemmas
convex on the back, rather firm, 5 to 7 nerved, usually acute or awned
from the apex ; palea shorter than the lemma.
Perennials or sometimes annuals, often with creeping rhizomes,
with usually erect culms and green or purplish, usually erect spikes.
Species about 60, in the temperate regions of both hemispheres ; about
25 species in the United States.
Type species: Agropyron triticeum Gaertn.
Agropyron Gaertn., Nov. Comm. Acad. Sci. Petrop. 14: 539, pi. 19, f. 4. 1770.
Gaertner describes two species, A. cristatum, based on Bromus cristatus L.,
and a new species, A. triticeum. The second species is figured. The species
are referred by some authors to Triticum. Some adopt the spelling Agropyrum.
The two original species of Agropyron are annuals, but all the
North American species are perennials. Nine of our species produce
creeping rhizomes. One of these is the well-known quack-grass or
couch-grass (A. repens (L.) Beauv.) (PI. IX; fig. 43), introduced
from Europe. On account of its rhizomes, it is a troublesome weed
in fields and meadows. Quack-grass can be distinguished by the
glabrous, awnless or short-awned lemmas, awn-pointed glumes, thin,
flat, usually sparsely pilose blades, and the yellowish rhizomes. An
allied native species, A. smitJiii Hydb., differs in its pale rhizomes
and its firm glaucous blades, soon involute in drying, the nerves
prominent on the upper side. This species, called western wheat-
grass and bluestem, is common west of the Mississippi River, where
it is one of the most important native forage grasses. Another com-
mon species of this group is A. dasystachyum (Hook.) Scribn. (in-
cluding A. sulvillosum (Hook.) E. Nels.), found along the Great
Lakes and westward.
Of the species without rhizomes seven have awnless or short-awned
lemmas. The commonest species of this group is A. tenerum Yasey,
called slender wheat-grass. This is an erect grass 2 to 4 feet high,
with flat blades and slender spikes, the broad glumes nearly as long
as the spikelet. It ranges from New England to Washington, and
southward in the Western States to Mexico. Slender wheat-grass
is an excellent forage grass and produces a good quality of hay. The
seed is offered by a few western seedsmen. This species is the only
native grass that has been successfully cultivated and whose seed is
on the market.
88
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
One of the long-awned species, Agropyron spicatum (Pursh)
Scribn. and Smith (A. divergent Nees), called bunch-grass, or more
distinctively blue bunch wheat-
grass, is of especial value as a
forage grass. It is 6ommon in the
Columbia Basin, where it is one of
the chief range grasses. The spe-
cies is distinguished by its erect
bunchy habit and by the spread-
ing awns of the lemmas, giving
the spike a bristly appearance.
FIG. 43. Quack-grass, Ayropyron repens. Plant, X 1 ; spikelet, X 3
Two of our species have disarticulating spikes, thus approaching
Sitanion. These are Agropyron saxicola (Scribn. and Smith) Piper,
of Washington, and A. scribneri Vasey, a spreading mountain species
Bui. 772, U. S. Dept. of Agriculture.
PLATE IX.
QUACK-GRASS (AGROPYRON REPENS).
Bui. 772, U. S. Dept. of Agriculture.
PLATE X.
BOTTLE-BRUSH GRASS (HYSTRIX PATULA).
A native species worthy of cultivation for ornament.
GENERA OF GRASSES OF THE UNITED STATES. 89
found at altitudes of 12,000 to 14,000 feet. In some species there are
two spikelets at the nodes of the rachis. This is especially frequent
in A. smithii and allies it with Elymus.
In general, all the species of Agropyron are forage grasses. They
form an important part of the forage on the western range and in
the valleys often grow in sufficient abundance to produce hay.
For a revision of the species of Agropyron found in the United
States, see Scribner and Smith, U, S. Dept. Agr., Div. Agrost. Bull.
4:25-36. 1897.
34. TBITICUM L.
Spikelets 2 to 5 flowered, solitary, sessile, placed flatwise at each
joint of a continuous or articulate rachis, the rachilla disarticulating
above the glumes and between the florets or continuous; glumes rigid,
3 to several nerved, the apex abruptly mucronate or toothed or with
one to many awns; lemmas keeled or rounded on the back, many-
nerved, ending in one to several teeth or awns.
Annual, low or rather tall grasses, with flat blades and terminal
spikes. Species about 10, southern Europe and western Asia; none
in the United States except Triticum aestiwum, the cultivated wheat.
Type species : Triticum aestivum L.
Triticum * L., Sp. PI. 85, 1753 ; Gen. PI., ed. 5, 37. 1754. Linnaeus describes
seven species, T. aestivum, T. hybernum, T. turgidum, T. spelta, T. monocoocum,
T. repens, T. caninum. The citation in the Genera Plantarum is to Tournefort's
figures 292 and 293 which represent, the first, beardless wheat, and the second,
bearded wheat. These two forms, beardless and bearded, are named by Lin-
naeus T. aestivum, the bearded wheat, and T, hybernum, the beardless wheat.
Triticum aestivum is chosen as the type because it has priority of position in
the Species Plantarum. Linnseus divides the genus into two groups, " annua "
and " perennia." The latter group, including Triticwm repens and T. caninum,
is now referred to Agropyron.
Zeia Lunell, Amer. Midi. Nat. 4 : 225. 1915. Based on " Triticum spelta
Linn." Agropyron Gaertn. is included in the genus proposed.
The most important species of Triticum is the cultivated wheat,
T. aestivum L. (T. vulgare Vill., T. satiwtm Lam.). A large
number of varieties are in cultivation, some with smooth lemmas,
some with velvety lemmas, some with long awns (fig. 44), some awn-
less (fig. 44, A). Durum wheat and club wheat are races, each with
several varieties. Triticum monococcum L., einkorn or 1-grained
wheat, is grown sparingly in Europe. Triticum dicoccwm Schrank,
emmer, is cultivated in this country as a forage plant. In emmer the
axis breaks up into joints, each joint bearing a spikelet which re-
mains entire, each floret permanently inclosing its grain. 2
1 In the Species Plantarum the word appears in the plural, Tritica, probably inadvert-
ently.
2 For a classification of wheats, see Jessen, Deutschlands Graser 191, 1863; Kornicke,
Handb. Getreidebaues 1: 40, 1885; Hackel in Engl. and Prantl, Pflanzenfam. II, 2: 80,
1887 ; True Grasses, translated by Scribner and Southworth, 180, 1890 ; Schulz, Mitt.
Natf. Ges. Halle 1: 14. 1911. For an account of T. dicoccoides Korn., recently found by
Aaronsohn on Mount Hermon, Palestine, see Aaronsohn, Verb. Zool. Bot. Ges. Wien 59:
485, 1909; U. S. Dept. Agr., Bur. PI. Ind. Bull. 180: 38, 1910; Cook, U. S. Dept. Agr.,
Bur. PI. Ind. Bull. 274. 1913.
90 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 44. Wheat, Triticum aestivum. Plant with awned spikes (bearded wheat) and
(A) a nearly awnless spike (beardless wheat), both X I ; spikelet and floret, X 3.
GENERA OF GRASSES OF THE UNITED STATES. 91
35. SECALE L.
Spikelets usually 2-flowered, solitary and sessile, placed flatwise
against the rachis ; the rachilla disarticulating above the glumes and
produced beyond the upper floret as a minute stipe ; glumes narrow,
rigid, acuminate or subulate-pointed ; lemmas broader, sharply keeled,
5-nerved, ciliate on the keel and exposed margins, tapering into a
long awn.
Erect, mostly annual grasses, with flat blades and dense terminal
spikes. Species five, in the temperate regions of Eurasia ; one species
cultivated in the United States and frequently escaped along way-
sides.
Type species : Secale cereale L.
Secale L., Sp. PI. 84, 1753 ; Gen. PI. 36. 1754. Linnaeus describes four species:
S. cereale, S. villosum, S. orientale, and . creticum. The second species is now
referred to Haynaldia, the third to Agropyron. The first species is chosen as
the type, as it is a well-known economic species.
Secale cereale (fig. 45), common rye, is cultivated extensively in
Europe and to some extent in the United States for the grain, but
here it is frequently grown as a forage crop. Rye is used for winter
forage in the South and for fall and spring pasture in the inter-
mediate region, and for green feed farther north. It is also used for
green manure and as a nurse crop for lawn mixtures, especially on
public grounds when it is desired to cover the ground quickly with a
green growth. Cultivated rye probably has been developed from the
wild perennial European species S. montanuwi Guss. In the wild
species of Secale the rachis disarticulates, but in 8. cereale it is con-
tinuous.
36. SCRIBNERIA Hack.
Spikelets 1-flowered, solitary, appressed and lateral to the some-
what thickened continuous rachis, the rachilla disarticulating above
the glumes, prolonged as a very minute hairy stipe;- glumes equal,
narrow,' firm, acute, keeled on the outer nerves, the first 2-nerved, the
second 4-nerved; floret with short hairs at the base; lemma shorter
than the glumes, membranaceous; rounded on the back, obscurely
nerved, the apex shortly bifid, the lobes obtuse, the faint midnerve
extending as a slender straight awn ; palea 2-nerved, about as long as
the lemma.
Low annual, with slender cylindric spikes. Species one.
Type species : Lepturus bolanderi Thurb.
Scribneria Hack., Bot. Gaz. 11: 105, pi. 5. 1886. One species described, based
on Lepturus bolanderi Thurb.
The single species, Scriltnerw "bolanderi (Thurb.) Hack. (fig. 46),
is found in sandy sterile ground in the mountains from central
California to Washington. It is too small and rare to be of economic
importance.
92 BULLETIN 772, IT. S. DEPARTMENT OF AGRICULTURE.
FIG. 45. Rye, 8ecale cereale. Plant, X i ; spikelet, X 3 ; floret showing rudiment back
of palea, X 5.
GENERA OF GRASSES OF THE UNITED STATES.
93
37. ELYMUS L.
Spikelets 2 to 6 flowered, sessile in pairs (rarely 3 or more or soli-
tary) at each node of a continuous rachis, the florets dorsiventral to
the rachis; rachilla disarticulating above the glumes and between the
florets; glumes equal, usually rigid, sometimes indurate below, nar-
row, sometimes subulate, 1 to several nerved, acute to aristate, some-
what asymmetric and often placed in front of the spikelets ; lemmas
rounded on the back or
nearly terete, obscurely
5-nerved, acute or usually
awned from the tip.
Erect, usually rather tall
grasses, with flat or rarely
convolute blades and ter-
minal spikes, the spikelets
usually crowded, some-
times somewhat distant.
Species about 45, in the
temperate regions of the
Northern Hemisphere; 25
species in the United
States, most of them in
the Western States.
Type species : Elymus sibiri-
cus L.
Elymus L., Sp. PI. 88, 1753 ;
Gen. PI., ed. 5, 36. 1754. Lin-
naeus describes five species, E.
arenarius, E. sibiricus, E. can-
adensis, E. virginicus, and E.
c<i put-medusae, all of which
are still retained in the genus.
The first use of the name Ely-
mus by Linnaeus was in his
Hortus Upsaliensis (1748),
where two species are de-
scribed, the first being cited in the Species Plantarum under E. virginicus
the second under E. sibiricus. Elymus 'sibiricus is chosen as the type because
it is the first of the five species in the Species Plantarum that is described in
the Hortus Upsaliensis.
Terrellia Lunell, Amer. Midi. Nat 4: 227. 1915. Proposed for Elymus L.,
not Elymus of various ancient authors.
The asymmetric glumes, in many species standing in front of the
spikelet instead of strictly distichous and in some species united at
the very base, have been the object of investigations as to their
morphological identity. Schenck 1 considers them, to be developed
from lateral branches at the base of the spikelet. Schuster 2 states
that the first or outer glume originates as a single organ but soon
FIG. 46. Scribneria bolanderi.
let with joint of rachis, X
view, X 5.
Plant, X I ; spike-
5 ; the same, front
iRot. Jahrb. Engler 40: 97-113. 1907.
3 Flora 100: 213-266, pi. 2-5. 1910.
94 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
divides into two parts, which stand side by side below the spikelet,
the second glume being suppressed.
In the group of Elymm virginicus L. and its allies the glumes are
indurate at the base and bowed out. They stand in front of the
spikelet rather than at each side, so that the contiguous glumes of
the pair of spikelets are not back to back but side by side. In
E. arenarius L., E. glaucus Buckl., and allied species, the glumes are
less distinctly in front of the spikelets. The rachis of the spike is
usually continuous but in E. saundersii Vasey, and, to a less extent, in
E. macounii Vasey, the rachis disarticulates, showing a transition
to Sitanion. In many species, such as E. simplex Scribn. and Merr.,
and E. salina Jones (named from Salina Pass), the middle spikelets
are in pairs, but those toward the base and apex of the spike are
single at the nodes. Such species are a transition to Agropyron.
On the other hand Agropyron smithii often has one or more pairs
of spikelets and may be considered a transition to Elymus. But in
the former species the glumes are narrow or almost subulate, which
shape is to be found in Elymus rather than in Agropyron. The
spikelets are usually not more than two at each node of the rachis,
but in E. trlticoides Buckl. there are often, and in E. condensatus
Presl. usually, more than two spikelets at each node. Sometimes in
the latter species (rarely in the former) the spike is branched so
that the inflorescence is a condensed panicle instead of a spike.
Elymus caput-medusae L. is an annual introduced from Europe ; the
other species are native perennials. Some species form extensively
creeping rhizomes, such as Elymus mollis Trin., of the sandy sea-
coasts of northern North America, E. flavescens Scribn. and Smith,
of the interior dunes of the Columbia River basin, and E. triticoides
Buckl., of alkaline soil of the Western States. Elymus canad^msis L.
(fig. 47) and E. virginicus, usually called wild rye, are common in
the eastern half of the United States. The first has a bushy nodding
head ; the latter an erect, stiff head.
The species of Elymus are for the most part good forage grasses,
and in some localities form a part of the native hay. In the wooded
areas of the Northwest, E. glcaivus Buckl. is one of the valuable sec-
ondary species on the ranges. It has flat, thin leaves, erect awned
spikes, broad glumes, and no rhizomes.
38. SITANION Raf.
Spikelets 2 to few flowered, the uppermost floret reduced, sessile,
usually 2 at each node of a disarticulating rachis, the rachis break-
ing at the base of each joint, remaining attached as a pointed stipe
to the spikelets above; glumes narrow or setaceous, 1 to 3 nerved,
the nerves prominent, extending into one to several awns, these
(when more than one) irregular in size, sometimes mere lateral
GENERA OF GRASSES OF THE UNITED STATES.
95
Fio. 47. Wild rye, Elymus canadenais. Plant, X 5 ; splkelet and floret, X 3.
98 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Erect perennials, with flat blades and bristly, loosely flowered
spikes. Species four, in temperate regions; one in the Himalayas,
one in New Zealand, and two in the United States.
Type species: Elymus hystrix L.
Asperella Humb., Magaz. Bot. Roem. and Usteri 7: 5, 1790, not Asprella
Schreb., 1789, a typonym of Homalocenchrus Mieg. A single species, A. hystrix,
based on Elymus hystrix L.
Hystrix Moench, Meth. PI. 294. 1794. One species described, H. patula,
based on Elymus hystrix L.
Gymnostichum Schreb., Beschr. Gras. 3: 127, pi. 47. 1810. One species de-
scribed, G. hystrix, based on Elymus hystrix L.
Our species are both woodland grasses, one, Hystrix patula Moench
(H. hystrix (L.) Millsp.) (PL X; fig. 49), in the Mississippi Valley
and eastward; the other, H. calif 'arnica (Boland.) Kuntze, in western
central California. They have little forage value, as they are no-
where abundant. The first species mentioned, sometimes called
bottle-brush grass, is worthy of cultivation for ornament.
40. HORDEUM L.
Spikelets 1 -flowered, 3 (sometimes 2) together at each node of the
articulate rachis (continuous in Hordeum vulgare}^ the back of
the lemma turned from the rachis, the middle one sessile or sub-
sessile, the lateral ones pediceled; rachilla disarticulating above the
glumes and, in the central spikelet, prolonged behind the palea as a
bristle and sometimes bearing a rudimentary floret; lateral spikelets
usually imperfect, sometimes reduced to bristles ; glumes narrow, often
subulate and awned, rigid, standing in front of the spikelet ; lemmas
rounded on the back, 5-nerved, usually obscurely so, tapering into a
usually long awn.
Annual or perennial low or rather tall grasses, with flat blades and
dense terminal cylindric spikes. Species about 20, in the temperate
regions of both hemispheres ; 10 species in the United States, 3 being
introduced from Europe.
Type species: Hordeum vulgare L.
Hordeum L., Sp. PI. 84, 1753; Gen. PI., ed. 5, 37. 1754. Linnaeus describes
six species, H. vulgare, H. hexastichon, H. distichon, H. zeocriton, H. murinum,
and H. jubatum. The citation given in the Genera Plantarum is to Tourne-
fort's plate 295, which represents Hordeum vulgare. This species is therefore
the type. All the Linnsean species are retained in the genus at present, but the
first four are usually considered to be forms of one species.
Zeocriton Beauv., Ess. Agrost. 114, pi. 21, f. 2. 1812. Ten species of
Hordeum having staminate or sterile lateral spikelets are included ; H. distichum,
the species figured, is taken as the type.
Critesion Raf., Journ. de Phys. 89: 103. 1819. A single species is described,
C. genicula-tus Raf. This is Hordeum jubatum L.
The most important species of the genus is Hordeum vulgare (fig.
50), the cultivated barley. This is an annual, resembling bearded
wheat, the awns as much as 6 inches long. In common or 4-rowed
barley the 3 spikelets of each cluster are fertile, the lateral spikelets of
GENERA OF GRASSES OF THE UNITED STATES. 99
the opposite sides of the spike being imbricate in a row, so that the
spike appears to be 4-rowed. In 6-rowed barley (H. hexastichon L.)
FIG. 49. Bottle-brush grass, Hystrix patula. Plant, X ; spikelet and floret, X 3.
the lateral spikelets form rather distinct rows. In 2-rowed barley
(H. distichon L.) the lateral spikelets are all infertile and reduced,
100 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Fio. 50. Barley, Hordeum vulgare. Plant, X i ; A, a spike of beardless barley, X i I
group of three spikelets and a floret, the latter showing the rudiment back of the
palea, X 3.
GENERA OF GRASSES OF THE TTFr^O SJ/ATES. 101
so that only the row of central spikelets on undi-sido 'oi tfe spike is
prominent. Naked barley is a kind of 2-rowed barley in which the
grain is free from the lemma and palea. Rice barley (H. zeocriton
L.), with spreading spikelets and divergent awns, is not grown in this
country and but sparingly in Europe. Beardless barley (H. vulgare
trifurcatum Wenderoth) (fig. 50, A) is a variety of 6-rowed barley
in which the awns are suppressed or converted into irregular short
lobes or teeth. Schulz 1 divides the cultivated barleys into two
groups. The first group, derived from II. spontomeum Koch, in-
cludes the 2-rowed varieties. The second group, derived from H.
ischnatherum (Coss.) Schulz, includes the 4 and 6 rowed varieties.
The glumes of Hordeum are thought by Schenck to be sterile spike-
lets or branchlets. (See footnote under Elymus, p. 93.)
Three common species of Hordeum are annuals. One of these,
II. pusillum Nutt., with glumes broadened above the base, is a native
species. The other two, introduced from Europe, are common weeds on
the Pacific coast. In 77. murmum, L. a part of the glumes are ciliate ;
in II. gussoneanum Parl. the glumes are setaceous, smooth below.
Hordeum nodosum L. (fig. 51) is similar to PI. pusillum but differs
in being perennial and in having uniformly subulate glumes. This
species is abundant throughout the western half of the United States.
Another perennial species, H. jubatum L., called squirreltail grass
because of its soft brushlike spikes, is common in the Western States,
where it is not infrequently a troublesome weed in alfalfa fields.
This species is called foxtail in Wyoming, barley grass in Utah, and
tickle grass in Nevada. Hordeum, murinum^ mentioned above, is
called barley grass, foxtail, and wild barley in different localities.
The species of Hordeum furnish forage during the early stages of
growth before the awns are produced. The mature spikes break up
into sharp-pointed joints that become a serious pest to stock. These
joints with the forwardly roughened awns work into the eyes and
nostrils of animals, causing inflammation.
For a revision of the species of Hordeum found in the United
States, see Scribner and Smith, U. S. Dept. Agr., Div. Agrost. Bull.
4:23-25. 1897.
41. LOLIUM L.
Spikelets several-flowered, solitary and sessile, placed edgewise to
the continuous rachis, one edge fitting to the alternate concavities, the
rachilla disarticulating above the glumes and between the florets ; first
glume wanting (except on the terminal spikelet), the second outward,
strongly 3 to 5 nerved, equaling or exceeding the second floret ; lemmas
rounded on the back, 5 to 7 nerved, obtuse, acute, or awned.
iMitt. Natf. Ges. Halle 1: 18. 1911.
102 BULLETIN 772 > U. 3. DEPARTMENT OF AGRICULTURE.
FIG. 51. Hordeum nodosum. Plant, X I. ; group of three spikelets with rachis joint
attached and a floret, the latter showing the rudiment back of the palea, X 3.
GENERA OF GRASSES OF THE UNITED STATES. 103
Annuals or perennials, with flat blades and simple terminal flat
spikes. Species about eight, in Eurasia, four of these being intro-
duced in the United States.
Type species : Lolium perenne L.
Lolium L., Sp. PI. 83, 1753 ; Gen. PL, ed. 5, 36. 1754. Linnaeus describes two
species, L. perenne and L. temulentum. The first is chosen as the type, as it is
an economic species. Both were described in the flora of Sweden.
Two species are of agricultural importance. Lolium perenne, Eng-
lish or perennial rye-grass, was the first meadow grass to be culti-
vated in Europe as a distinct segregated species, the meadows and
pastures formerly being mixed native species. This and the next are
probably the most important of the European forage grasses. Eng-
lish rye-grass is a biennial or short-lived perennial, 2 to 3 feet tall,
with glossy dark-green leaves and a slender spike as much as a foot
long, the spikelets 8 to 10 flowered, somewhat longer than the glume,
the lemmas awnless. Italian rye-grass, L. multiflorum Lam. (L. itali-
cum A. Br.) (PL XI; fig. 52), differs from the preceding in having
awned lemmas and usually a greater number of florets to the spikelet.
Both species are used to a limited extent for meadow, pasture, and
lawn. They are of some importance in the South for winter forage.
Lolium multiftorum is common in the humid region of the Pacific
coast, where it is often called Australian rye-grass.
In the Eastern States the rye-grasses are often sown in mixtures
for parks or public grounds, where a vigorous early growth is re-
quired. The young plants can be distinguished from bluegrass by the
glossy dark-green foliage.
Lolium temulentum L., darnel, is occasionally found as a weed in
grain fields and waste places. It is in bad repute, because of the pres-
ence in the fruit of a narcotic poison, said to be due to a fungus. Dar-
nel is supposed to be the plant referred to as the tares sown by the
enemy in the parable of Scripture. It is an annual, with glumes as
much as an inch long and exceeding the 5 to 7 florets.
42. LEPTURUS R. Br.
(Monerma Beauv.)
Spikelets 1-flowered, embedded in the hard, cylindric, articulate
rachis, placed edgewise thereto, the first glume wanting except on the
terminal spikelet, the second glume closing the cavity of the rachis
and flush with the surface, indurate, nerved, acuminate, longer than
the joint of the rachis ; lemma lying next the rachis, hyaline, shorter
than the glume, 3-nerved ; palea hyaline, 2-nerved, a little shorter than
the lemma; rachilla not disjointing, the spikelet falling entire, at-
tached to its rachis joint.
Low annuals or perennials, with hard cylindric spikes. Species
three, all from the Eastern Hemisphere, one introduced in California.
104 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 52. Italian rye-grass, Lolium multifiorum. Plant, X I ; spikelet, X 3 ; floret, X 5.
Bui. 772, U. S. Dept. of Agriculture.
PLATE XI,
ITALIAN RYE-GRASS (LOLIUM MULTIFLORUM).
Bui. 772, U. S. Dept. of Agriculture.
PLATE XII.
TALL OAT-GRASS (ARRHENATHERUM ELATIUS).
GENEKA OF GRASSES OF THE UNITED STATES.
105
Type species : Rottboellia repcns Forst.
Lepturus R. Br., Prodr. Fl. Nov. Holl. 207. 1810. One species described L
repens, based on Rottboellia repens Forst.
Monerma Beauv.,
Ess. Agrost. 116,
pi. 20, f. 10. 1812.
The species figured
is M . monandra,
which is Lepturus
cylindrica.
Leptocercus Raf.,
Amer. Monthly
Mag. 4: 190. 1819.
In a review of Nuttall's
Genera Rafinesque changes
the name Lepturus R. Br. to
Leptocercus because of a
genus of insects by the name
of Leptura.
Our one species, Lep-
turus cylindrica (Willd.)
Trin. (fig. 53), is intro-
duced in salt marshes
from San Francisco to
San Diego. At matur-
ity the spike breaks up
into the 1 -seeded joints.
The species has no eco-
nomic value. For other
species that have been
referred to Lepturus. see
Pholiurus.
43. PHOLIURUS Trin.
(Lepturus of authors, not
R. Br.)
Fie. ^.-Lcvturus cylinartca. Plant, X 1' ^pikelets 1 or 2 HOW-
spikelet with a joint of the rachis, x 5 ; spike- erecl ? embedded in the
let, front view, x 5. articulate rachis and
falling attached to the joints; glumes two, placed in front of the
spikelet and inclosing it, coriaceous, 5-nerved, acute, asymmetric,
106
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
appearing like halves of a single split glume ; lemma lying next to the
axis, smaller than the glumes, hyaline, keeled, scarcely more than
1-nerved ; palea a little shorter than the lemma, hyaline, 2-nerved.
Low annuals, with cylindric spikes. Species four, in the Eastern
Hemisphere, one introduced into the United States.
Type species : Roffboellia pannonica Host.
Pholiurus Trin., Fund. Agrost. 131. 1820. Based on a single species. Rott-
boellia pannonica Host. This species has 2-flowered spikelets.
Lepiurus Dumort., Obs. Gram. Beige 140, pi. 15, f. 57. 1823. A single species
based on " Rottbolia incurvata L." fils.
The species of Pholiurus have been referred by most recent authors
to Lepturus, the type of which was, by
the same authors; referred to Monerma.
Our species, Pholiurus incurvatus (L) .
Hitchc. (Aegilops incurvata L., 1 Lep-
turus filiformis (Eoth.) Trin.) (fig. 54),
has 1-flowered spikelets. It is intro-
duced along the borders of salt marshes
FIG. 54. Pholiurus incur vatuti. Plant, x i ; spikelet with a joint of the rachis, X 5 ;
spikelet, front view, X 5.
from Maryland to Virginia and from Marin County to San Diego,
Calif. It has no economic value.
4. AVENEAE, THE OAT TRIBE.
44. KOELERIA Pers.
Spikelets 2 to 4 flowered, compressed, the rachilla disarticulating
above the glumes and between the florets, prolonged beyond the per-
fect florets as a slender bristle or bearing a reduced or sterile floret at
the tip ; glumes usually about equal in length but unequal in shape,
the lower narrow and sometimes shorter, 1-nerved, the upper some-
what broader above the middle, wider than the lower, 3 to 5 nerved ;
1 Sp. PI. ed. 2. 2: 1490. 1763.
GENERA OF GRASSES OF THE UNITED STATES. 107
lemmas somewhat scarious and shining, the lowermost a little longer
than the glume, obscurely 5-nerved, acute or short-awned, the awn,
if present, borne just below the apex.
Annual or perennial," slender, low or rather tall grasses, with nar-
row blades and spikelike panicles. Species about 20, in the temperate
regions of both hemispheres; two species in the United States, one
native and one introduced.
Type species : Aira cristata L.
Koeleria Pers., Syn. PI. 1 : 97. 1805, Persoon describes five species, K. yra-
cilis, K. cristata, K. tuberosa, K. phleoides, and K. villosa. Of these, K. cristata
and K. phleoides were described by Linnaeus, the first under Aira, the second
under Festuca. The first of these is selected as the type, as it has priority of
position in the Species Plantarum.
Airochloa Link, Hort. Berol, 1 : 126. 1827. Six species are included. Koeleria
cristata, upon which the first species is based, is taken as the type.
Brachystylus Dulac, Fl. Hautes Pyr. 85. 1867. Based on " Koeleria Pers."
Recently a monograph of Koeleria was published by Domin 1 in which many
species were described. Several of these were based upon material from the
United States but appear to be only forms of the widely distributed K. cristata.
Koeleria cristata (L.) Pers. (fig. 55) is the only species native in
North America. This is a common constituent of grassland on prai-
ries, plains, and in open woods from Ontario to British Columbia and
south to northern Mexico. It is a cespitose perennial, with slender,
erect culms a foot or two high, with a pale, shining, densely flowered
panicle 2 to. 5 inches long. The species varies much, but the forms,
except K. cristata longifolia Yasey, of California, with longer blades
and larger, more open panicles, can not be distinguished as varieties.
The slender form, of the semiarid plains and foothills of the West,
is held by some as distinct and called K. grocilis Pers. The
spikelets of K. cristata are mostly 2 or 3 flowered, with a slender
prolongation of the rachilla, and the lemmas are acute or mucronate,
but not awned. The habit suggests a species of Poa, from which
genus it is distinguished by its mostly 2 or 3 flowered spikelets, acute
lemmas, and the culm puberulent below the panicle. A second
species, K. phleoides (Vill.) Pers., a low annual with short-awned
lemmas, is introduced from Europe in a few localities. Hackel (Nat.
Pfl anzenf am. ) places Koeleria in the FestuceaB, but South American
and Old World species of Koeleria, with lemmas awned below the
apex, as well as the shining culm and spikelets of K. cristata^ show
clearly an affinity to Trisetum. For this reason the genus is here
placed in Aveneae, although the glumes do not exceed the florets as
they do in nearly all the Aveneae.
Koeleria cristata is a good forage grass and is a constituent of
much of the native pasture throughout the Western States.
45. TRISETUM Pers.
Spikelets usually 2-flowered, sometimes 3 to 5 flowered, the rachilla
prolonged behind the upper floret, usually villous ; glumes somewhat
1 Monographic der Gattung Koeleria. 1907.
108 BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE.
unequal, acute, awnless, the second usually longer than the first
floret; lemmas usually short-bearded at the base, 2-toothed at the
apex, the teeth often awned, bear-
ing from the back below the
cleft apex a straight and in-
cluded, or usually bent and ex-
serted, awn.
Tufted perennials with flat
blades and open or usually con-
tracted or spikelike panicles.
Species about 65, in the arctic
and temperate regions of both
hemispheres ; eight species in the
United States, mostly in the
mountains.
Type species : Arena flavescens L.
Trisetum Pers., Syn. PI. 1: 97. 1805.
Persoon describes 11 species. The
seventh species, T. pratense Pers.,
based on Avena flavescens L., is chosen
as the type, because it is historically
the oldest species.
Graphephorum Desv., Nouv. Bull.
Soc. Philom. Paris 2: 189. 1810.
Based on Aira melicoides Michx.
The name Trisetum refers to
the three awns on the lemma of
many of the species, one from the
back and one from each of the
teeth. In two of our species, T.
melicoideum (Michx.) Scribn.
and T. wolfii Vasey, the awn
from the back is included within
the glume or is wanting. Trise-
tum spicatum (L.) Eichter (fig.
56) is found at high altitudes in
all the western mountains and is
widespread at high altitudes and
in the arctic regions of the North-
ern Hemisphere. It is an erect
grass with a spikelike, often
dark-colored panicle, the awn
exserted and bent. Trisetum
canes cens BuckL, of the Western
States, is a woodland grass with
narrow but rather loose panicles. Trisetum cernuum Trin., of the
Northwest, has broad flat blades and a loose open penicle, with lax
FIG. 55. Koeleria cristata.
spikelet and floret,
Plant,
X 5.
X I
GENERA OF GRASSES OF THE UNITED STATES.
109
drooping branches, the florets distant in the usually 3-flowered spike-
lets. Trisetum pennsylvanicum (L.) Roem. and Schult. (Sphenopholis
palustris (Michx.)
Scribn.), T. hallii
Scribn., and T. inter-
ruptum Buckl. have
been referred to
Sphenopholis. I n
the first, the upper
lemma is slightly
bearded at base, the
lower glabrous ; in
the other two, the
lemmas are glabrous.
In these three species
the articulation is be-
low the spikelet, as in
Sphenopholis, for
which reason Scrib-
ner placed them in
that genus, but their
a w n e d, relatively
thin lemmas and
their glumes alike in
shape place them
more naturally in
Trisetum.
FIG. 56. Trisetum spicatum. Plant, X I ; spikelet and floret, X 5.
The species of Trisetum are all valuable for grazing. Trisetum
spicatum constitutes an important part of the forage on alpine slopes.
110 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
46. SPHEXOPHOLIS Scribn.
(Eatonia of authors, not Raf.)
Spikelets 2 or 3 flowered, the pedicel disarticulating below the
glumes, the rachilla produced beyond the upper floret as a slender
bristle ; glumes unlike in shape, the first narrow, acute, 1-nerved, the
second broadly obovate, 3 to 5 nerved, somewhat coriaceous; lemmas
firm, scarcely nerved, awnless, the first a little shorter or a little
longer than the second glume.
Perennial grasses, with usually flat blades and narrow panicles.
Species four, in the United States, extending into Mexico and the
West Indies.
Type species: Aim obhifuita Miehx.
Reboulea Kunth, Rev. Gram. 1: 341, pi. 84, 1830, not Rebouillia Raddi, 1818.
A', gracilis, the only species described, is the same as Aira obtusata Michx.
Colobanthus (Trin.) Spach. Suites Buff. 13: 163, 1846, not Bartl., 1830.
Trinius applied the name to a section of Trisetum. The type is Koeleria penn-
sylvanica DC. (Sphenopholis pallens), the first of two species mentioned by
Trinius, the other being Aira obtiisata Michx.
Sphenopholis Scribn., Rhodora 8 : 142. 1906. A new name is proposed for the
group of grasses then known as Eatonia, and the type species is designated.
Scribner showed that the original description of Eatonia Raf. could not apply
to the genus as later described by Endlicher. 1 The type species of Eatonia Raf.
proves to be Panicum virgatum. 2 The genus Sphenopholis was revised by Scrib-
ner in the above-mentioned paper.
One species, Sphenopholis obtwata (Michx.) Scribn. (fig. 57), is
widespread, but not very abundant, throughout the eastern half of
the United States. In the western portion of its range the panicle is
condensed and spikelike (var. lolata (Trin.) Scribn.). All the
species are forage grasses, but they are usually not abundant enough
to be of much importance.
47. AVENA L., oats.
Spikelets 2 to several flowered, the rachilla bearded, disarticulating
above the glumes and between the florets ; glumes about equal, mem-
branaceous or papery, several-nerved, longer than the lower floret,
usually exceeding the upper floret ; lemmas indurate, except toward
the summit, 5 to 9 nerved, bidentate at the apex, bearing a dorsal bent
and twisted awn (this straight and reduced in Avena sativa).
Annual or perennial, low or moderately tall grasses, with narrow or
open, usually rather few-flowered panicles of usually large spikelets.
Species about 55, in the temperate regions; only a few in the Western
Hemisphere; 7 species in the United States, only 2 being native.
Type species : Avena sativa L.
Avena L., Sp. PI. 79, 1753; Gen. PI., ed. 5, 34. 1754. Linnaeus describes 10
species, 3 of which are now retained in Avena. These are A. sativa, A. fatiia,
and A. pratensis. The other species are now referred as follows : A. sibirica to
. PI. 99. 1837. 2 Hitchcock, Contr. U. S. Nat Herb. 15:87. 1910.
GENERA OF GRASSES OF THE UNITED STATES.
Ill
Stipa, A. elatior to Arrhenatherum, A. pennsylvanica to Trisetum, A. flavescens
to Trisetum, A. fra'gilis to Gaudinia, A.,spicata to Danthonia. In the Genera
FIG. 57. Sphenopholis obtusata. Plant, X i ; spike-
let and floret, X 5.
Plantarum, Linnaeus cites
Tournefort's figure 26 f
(error for 297), which is
Avena sat iva,. Hence
this is the type species.
The most impor-
tant species of the
genus is Avena sativa,
the familiar culti-
vated oat. In many
of the varieties the
awn is straight, often
reduced, or even want-
ing. The spikelets
contain usually two
florets that do not
easily disarticulate.
The lemmas are
smooth or slightly
hairy at the base, the
apical teeth acute but
not awned. The grain
is permanently in-
closed in the lemma
and palea. Two other
introduced species are
known as wild oats,
because of their close
resemblance to the
cultivated oat. Avena
fatua L. (fig. 58) dif-
fers from A. sativa
in the readily disar-
ticulating florets, be-
set with stiff, usually
brown hairs, and in
he well-developed
. . J
geniculate and twisted
awn. A variety of this (A. fatua glalrata Peterm.) has glabrous
112 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
florets. In our other species of wild oats, A. barbata Brot., the
pedicels are more slender, the spikelets pendulous, and the teeth of
FIG. 58. Wild oats, Avena fatua. Plant, X I ; spikelet and floret, X 2.
the lemma are prolonged into delicate awns. These species of wild
oats are common on the Pacific coast, where they are weeds, but are
GENEKA OF GRASSES OF THE UNITED STATES. 113
utilized for hay. Much of the grain hay of that region is made from
either cultivated or wild oats.
The varieties of cultivated oat are derived from three species of
Avena. The common varieties of this country and of temperate and
mountain regions in general are derived from A. faitua. The
Algerian oat grown in North Africa and Italy and the red oat of our
Southern States are derived from A. sterUis. A few varieties
adapted to dry countries are derived from A. bar'bata'*-.
Avena sterilis L., animated oats, is sometimes cultivated as a
curiosity. When laid on the hand or other moist surface the fruits
twist and untwist as they lose or absorb moisture.
Our two native species, found in the Rocky Mountain region, are
perennials, with narrow few-flowered panicles of erect spikelets
smaller than those of Avena sativa. They are excellent forage
grasses, but occur only scatteredly.
48. AREHENATHERUM Beauv.
Spikelets 2-flowered, he lower floret staminate, the upper perfect,
the rachilla disarticulating above the glumes, produced beyond the
florets as a slender bristle ; glumes rather broad and papery, the first
1-nerved, the second a little longer than the first and about as long
as the spikelet, 3-nerved; lemmas 5-nerved, hairy on the callus, the
lower bearing near the base a twisted, geniculate, exserted awn, the
upper bearing a short, straight, slender awn just below the tip.
Perennial, rather tall grasses, with- flat blades and rather dense
panicles. Species about six, in the temperate regions of Eurasia;
' one species introduced into the United States.
Type species : Arrhenatherum avenaceum Beauv.
Arrhenatherum Beauv., Ess. Agrost. 55, pi. 11, f. 5. 1812. Beauvois figures
one species, which he calls Arrhenatherum avenaceum. This is Avena elatior
L., and is now called Arrhenatherum elatius (L.) Mert. and Koch.
Arrhenatherum elatius (PI. XII; fig. 59) is occasionally cultivated
in the humid regions of the United States as a meadow grass under
the name of tall oat-grass. It is a fairly satisfactory forage grass,
but the seed is expensive and often of poor quality. This species is
often found growing spontaneously* in grassland and along road-
sides in the Northern States.
A variety, Arrhenatherum elatius bulb o sum (Presl) Koch, has ap-
peared recently in some of the Atlantic States. It differs from the
ordinary form in having at the base of the stem a moniliform string
of 2 to 5 small corms 5 to 10 mm. in diameter.
1 See Journ. Hered, 5 : 56, 1914, a translation of an article by Trabut. Also see Norton,
Amer. Breed. Assoc. 3: 281. 1907.
97769 19 Bull. 772 8
114 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
49. AIRA L.
(Descliampsia Beauv.)
Spikelets 2-flowered, disarticulating above the glumes, the hairy
rachilla prolonged behind the upper floret as a stipe, this sometimes
bearing a reduced floret; glumes about equal, acute
or acutish, membranaceous ; lemmas thin, truncate
and 2 to 4 toothed at the summit, bearing a slender
awn from or below the middle, the awn straight, bent,
or twisted.
Low or moderately tall
annual or usually peren-
nial grasses, with shining
pale or purplish spikelets
in narrow or open pani-
cles. Species about 35, in
the temperate and cool
regions of both hemispheres, 6 of these
being in the United States.
Type species : Aira caespitosa L.
Aira L., Sp. PI. 63, 1753 ; Gen. PI., eel. 5, 31.
1754. Fourteen species are described. The
name was first used for a genus by Linnaeus
in his Flora Lapponica in 1737, where he
describes four species. These four species
are named in the Species Plantarum : 7. A.
spicata, 8. A. caespitosa, 9. A. flexuosa, 10.
A. montana. The first of these, A..spicata,
is referred to Trisetum ; the other three be-
long to Deschampsla, as recognized in most
American botanies. The genus Aira, as
accepted by Bentham and Hooker in the
Genera Plantarum and by Hackel in the
Natiirlichen Pflanzenfamilien, is based upon
the last two of the original Linnseari
FIG. 59. Tall oat-grass, Arrhenathcrum elatius. Plant, X i ; spikelet and fertile floret,
X 5.
GENERA OF GRASSES OF THE UNITED STATES.
115
FIG. 60, Tufted hair-grass, Aira caespitosa. Plant, X ; spikelet and two views of
floret, X 5.
116 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
species, A. praecox and A. caryophyUca, which are found in southern Europe
and are not described by Linnaeus in his Flora Lapponica nor in his Flora
Suecica. Linnseus's generic idea of Aira is evidently represented by the four
species first included in the genus. From these Aira caespitosa is arbitrarily
selected as the type.
Deschampsia Beauv., Ess. Agrost. 91, pi. 18, f. 3. 1812. The figured species,
the type, is D. caespitosa.
Lerchenfeldia Schur., Enum. PI. Transs. 753. 1866. Three species are in-
cluded. Aira flexuosa L., on which L. flexuosa is based, is taken as the type.
Aira danthonioides Trin. of the Pacific coast is an annual. Aira
caespitosa L. (Deschampsia caespitosa Beauv.) (fig. 60) is common
in moist or wet soil from Newfoundland to Alaska and south to New
Jersey, Illinois, and, in the western mountains, to New Mexico and
southern California. It is a tufted perennial 1 to 4 feet high, with
smooth, narrow, folded blades and open drooping panicles, 4 to 12
inches long, of shining pale-bronze or purplish spikelets. This spe-
cies, sometimes called tufted hair-grass, is often the dominant grass
in mountain meadows, where it furnishes excellent forage.
50. ASPEIS Adans.
(Aira of authors.)
Spikelets 2-flowered, the rachilla disarticulating above the glumes,
not prolonged; glumes about equal, acute, membranaceous or sub-
scarious ; lemmas firm, rounded on the back, tapering into two slender
teeth, the callus with a very short tuft of hairs, bearing on the back
below the middle a slender, geniculate, twisted, usually exserted awn,
this reduced or wanting in the lower floret in one species.
Low, delicate annuals with small open or contracted panicles. Spe-
cies about nine, in southern Europe, three being introduced in the
United States.
Type species : Aira praecor L.
Aspris Adans., Fam. PL 2: 496, 522. 1763. The references cited are also
cited by Linnseus under Aira praecox.
Caryophyllea Opiz, Seznam 27. 1852. Based on Aira caryophyllea.
Fussia Schur., Enum. PI. Transs. 754. 1866. Three species, F. praecox, F.
caryophyllea, and F. capillaris, are included. Aira praecox, upon which the
first species is based, is taken as the type.
Our three species are Aspris caryopJiyllea (L.) Nash (fig. 61), A.
praecox (L.) Nash, and A. capillaris (Host) Hitchc. ( Aira capillaris
Host) . They are found frequently on the Pacific coast and occasion-
ally in the Eastern States. The species are of no economic importance.
Weingaertneria canescens Bernh. has been found upon ballast at
Philadelphia and on Marthas Vineyard. This is a low, tufted annual
with pale, contracted panicles, differing from the species of Aspris in
having club-shaped awns.
51. NOTHOLCUS Nash.
(Holcus of authors.)
Spikelets 2-flowered. the pedicel disarticulating below the glumes,
the rachilla curved and somewhat elongate below the first floret, not
prolonged above the second floret; glumes about equal, longer than
GENERA OF GRASSES OF THE UNITED STATES.
117
the two florets; first floret perfect, its lemma awnless; second floret
staminate, its lemma awned on the back.
FIG. 61. Aspris caryopliyllea. Plant, X 1 ; spikelet and two views of floret, X 5.
Perennial grasses, with flat blades and contracted panicles. Species
about eight, Europe and Africa; two introduced into the United
States.
Type species : Holcus lanatus L.
Ginannia Bubani, Fl. Pyren. 4: 321, 1901, not Scop., 1777, nor Dietr., 1804.
P.ased on " Holcus L. et Auctor.," the two species included, G. pubesccns and O.
molli-x, showing that it is to the species congeneric with Holcus lanatus L. that
the name is applied.
118 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Notholcus Xash; Hitch., in Jepson, Fl. Calif. 3: 128. 1912. Only one species
described. Notholcus is derived from the Greek nothos, false, and Holcus, the
generic name formerly applied to this group. Nash 1 spells the name Nothoholcus.
For a discussion of the reasons for the change of name, see page 266. The ge-
neric name Holcus is there applied to the sorghums, necessitating a new name
for the velvet grass.
The common species in the United States is Notholcus lanatus
(L.) Nash (Holcus lanatus L.), known as velvet grass (fig. 62).
This species is introduced in various places in the Eastern States
and also on the Pacific coast, where it is abundant. It is an erect,
grayish, velvety-pubescent grass 2 to 3 feet tall, with a contracted
pale or purplish panicle 2 to 4 inches long. Velvet grass is some-
times recommended as a meadow grass, but for this purpose it has
little value except on moist sandy or sterile soil where other grasses
will not thrive. It has been used with some success in sandy fields
around the mouth of the Columbia River in Washington and Oregon.
A second species, Notholcus mollis (L.) Hitchc., with creeping
rhizomes, has been introduced in California, where it is rare.
52. DANTHONIA Lam. and DC.
Spikelets several-flowered, the rachilla readily disarticulating
above the glumes and between the florets ; glumes about equal, broad
and papery, acute, mostly exceeding the uppermost floret; lemmas
rounded on the back, obscurely several-nerved, the base with a strong
callus, the apex bifid, the lobes acute, usually extending into slender
awns, a stout awn arising from between the lobes ; awn flat, tightly
twisted below, geniculate, exserted, including three nerves of the
lemma.
Tufted, low or moderately tall perennials, with few-flowered, open,
or spikelike panicles of rather large spikelets. Species about 100, in
the temperate regions of both hemispheres; especially abundant in
South Africa ; 12 species in the United States, about equally divided
between the Eastern and the Western States.
Type species : Avena spicata L.
Danthonia Lam. and DC., Fl. Franc. 3: 32. 1805. The work cited is a local
flora in which the two French species are described, D. decumbent (which is
the same as Xicfillnyia (lecuiubcnx) and D. prorincialis. The authors, however,
mention in the paragraph preceding the one devoted to the generic description
that "besides the species described below one ought to refer to this genus, 1st,
Avena spicata L. or Avena ylumosa Michx. ; 2d, Arena cfilicina Lam. not Vill."
Of the four species mentioned, three are congeneric with Avena spicata and
correspond with the generic description better than does Danthonia decumbens,
which is the first species described under Danthonia. Avena spicata is se-
lected as the type of Dauthonia. 2 Piper 3 has selected Festuca decumbens L.
(Danthonia decumbens) as the type of Danthonia because it is the first species
described under Danthonia, and takes up Merathrepta Raf. for the species
generally referred to Danthonia. Nelson and Macbride 4 take up Pentameris
Beauv. in place of Merathrepta.
iBritt. and Brown, Illustr. Fl., ed. 2. 1: 214. 1913.
2 See Hitchc., Bot. Gaz. 57 : 328. 1914.
sContr. T T . S. Xat. Herb. 11: 122. 1906.
*Bot. Gaz. 56: 469. 1913.
GENERA OF GRASSES OF THE UNITED STATES.
119
PIG. 62. Velvet grass, Xotliolcns la nut us. Plant, X l; spikelet, florets with glumes
removed, arid mature fertile floret, all X 5.
120 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Pentameris Beauv., Ess. Agrost. 92, pi. 18, f. 8. 1812. P. tlmarii is the type,
as this is the single species mentioned and figured. This is a South African
species and represents a group in
which the lateral teeth of the lemmas
are 2-awned. The group is considered
to be generically distinct from Dan-
thonia by Stapf. 1 The name is taken
up by Nelson and Macbride in place of
Merathrepta Raf. 2
Merathrepta Rat, Bull. Bot. Seringe
1: 221. 1830. The genus is described
briefly and Arena spicata mentioned.
This species is, therefore, the type.
One species of Danthqnia, D.
spicata (L.) Beauv. (fig. 63), is
common on sterile hills and in
dry, open woods in the Eastern
States, where it is sometimes
called poverty grass. It can be
recognized, even when not in
flower, by its small tufts of curly
leaves. In the Western States
the species are found in grass-
land and contribute somewhat
toward the forage value of the
range, but usually they are not
abundant. All our species pro-
duce cleistogenes (enlarged fer-
tile cleistogamous spikelets) in
the lower sheaths, 3 and the culms
finally disarticulate at the nodes
below these.
FIG. G3. Wild oat-grass, Danthonia spicata. Plant, X I ', spikelet, floret, and a cleisfo-
gene from the axil of a lower leaf, all X 5.
1 Thiselt. Dyer, Fl. Cap. 7 : 512. 1898.
2 See following paragraph on Merathrepta.
3 Chase, Amer. Journ. Bot. 5:254. 1918.
GENERA OF GRASSES OF THE UNITED STATES. 121
5. AGROSTIDEAE, THE TIMOTHY TRIBE.
53. CALAMAGROSTIS Adans.
Spikelets 1-flowered, the rachilla disarticulating above the glumes,
usually prolonged behind the palea as a short, commonly hairy bristle ;
glumes about equal, acute or acuminate; lemma shorter and usually
more delicate than the glumes, the callus bearing a tuft of hairs,
which are often copious and as long as the lemma, awned from the
back, usually below the middle, the awn being delicate and straight,
or stouter and exserted, bent and sometimes twisted; palea shorter
than the lemma.
Perennial, usually moderately tall or robust grasses, with small
spikelets in open or usually narrow, sometimes spikelike panicles.
Species over 100, in the cool and temperate regions of both hemi-
spheres ; 26 species in the United States, mostly in the western moun-
tains.
Type species: Arundo calamagrostix L.
Calamagrostis Adans., Fam. PI. 2: 31, 530. 1763. Adanson describes no
species but in the index there is given under Kalamagrostis Diosk., three names
or citiations, Negil. Arab., Gramen. Sheuz. t. 3. f. 5., and Arundo Lin. The
reference to Scheuchzer is found in Linnseus's Species Plantarum under Arundo
calamagrostis (1: 82), which consequently is the type of Calamagrostis.
Deyeuxia Clarion; Beauv., Ess. Agrost. 43, pi. 9, f. 9, 10. 1812. Type, D.
montana, the first of the two species figured.
Amagris Raf., Princip. Fondarnent. Somiologie 27. 1814. A new name pro-
posed for Calamagrostis, because that is formed of two other names.
Athernotus Dulac, Fl. Hautes Pyr. 74. 1867. Based on " Calamagrostis Ad."
Lunell * uses this name for Calamovilfa, but Dulac bases the genus on Cala-
magrostis Adans., and the three species he includes belong in Calamagrostis,
not in Calamovilfa.
By some authors the species with prolonged rachilla are segregated
as a distinct genus, Deyeuxia, the name Calamagrostis being retained
for those species in which the rachilla is not prolonged. The Ameri-
can species all belong to the section Deyeuxia.
Four Pacific coast species have loose, open panicles. In all the
other species the panicle is rather compact, in some cases spikelike.
The commonest species in the United States is CaZaanagrostis cana-
densis (Michx.) Beauv. (fig. 64), growing in swamps and low ground
from New England to Oregon, and southward in the mountains and
northward to the arctic circle. It is an important source of wild hay
from Wisconsin to North Dakota, but is of only medium value for
grazing. Much of the marsh hay of Wisconsin and Minnesota be-
longs to this species, which in that region is called blue joint. This is
the dominant grass in the interior of Alaska. The species is distin-
guished by having flat blades, a somewhat lax, usually nodding
panicle, the hairs at the base of the floret copious and as long as the
lemma, the awn straight, delicate, not exserted beyond the glumes, the
latter 3 to 5 mm. long.
i Amor. Midi. Nat. 4: 218. 1915.
122 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. G4. Bluojoint, Cala-mauruatis canadcnais- Plant, X \ ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 123
C alamagrostis scabra Presl, closely allied to the above, but with
somewhat larger spikelets, is abundant along the coast from Oregon
to Alaska. This has been incorrectly referred to C. langsdorfii
(Trin.) Link, of Siberia. In general, the species of Calamagrostis
are important forage grasses. Pine-grass (C. rubescens Buckl.) is
common in the mountains of Oregon and Washington, where it forms
an important part of the forage.
For a revision of the species of Calamagrostis found in the United
States, see Kearney, U. S. Dept. Agr., Div. Agrost. Bull. 11. 1898.
54. AMMOPHILA Host.
Spikelets 1 -flowered, compressed, the rachilla disarticulating above
the glumes, produced beyond the palea as a short bristle, hairy above;
glumes about equal, chartaceous ; lemma similar to and a little shorter
than the glumes, the callus bearing a tuft of short hairs ; palea nearly
as long as the lemma.
A tough, rather coarse, erect perennial, with hard, scaly, creeping
rhizomes, long, tough, involute blades, and a pale, dense, spikelike
panicle. One species is found on the sandy seacoast of Europe and
northern .North America as far south as North Carolina and on the
shores of the Great Lakes, a second species around the Baltic.
Type species: Arundo arenaria L.
Ammophila Host, Gram. Austr. 4: 24, pi. 41. 1809. Only one species de-
scribed. A. anmdinacea Host, based on Arundo arenaria L.
Psamma Beaiiv., Ess. Agrost. 143, pi. 6, f. 1. 1812. The one species, P.
Uttoralis, is Ammophila arenaria.
AmmopMla arenaria (L.) Link (fig. 65) is an important sand-
binding grass in Europe, being used there to hold the barrier
dunes along the coast. In this country it has been tried with success
on Cape Cod and at Golden Gate Park, San Francisco. 1 It is called
beach-grass and less frequently marram grass and sea marram.
55. CALAMOVILFA Hack.
Spikelets 1-flowered, the rachilla disarticulating above the glumes,
not prolonged behind the palea ; glumes unequal, acute, chartaceous ;
lemma a little longer than the second glume, chartaceous, awnless,
glabrous or pubescent, the callus bearded ; palea about as long as the
lemma.
Perennial, rigid, usually tall grasses, with narrow or open panicles,
some species with creeping rhizomes. Species four, confined to the
United States and southern Canada.
Type species : Calam.agrostis brevipilis Gray.
Calamovilfa Hack., True Grasses 113. 1890. The True Grasses is a transla-
tion by Scribner and Southworth of the article on grasses in Engler and Prantl's
Natiirliclien Pflanzenfamilien. Scribner has added bracketed notes. In a para-
1 For a full discussion, see Hitchcock, U. S. Dept. Agr., Bur. PI. Ind. Bull. 57 ; Westgate,
U. S. Dept. Agr., Bur. PI. Ind. Bull. 05. 1904.
124 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 65. Beach-grass, AmmopJiila arenaria. Plant, X J ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 125
graph quoted from Hackel ("Hackel in MS.") is a statement that two species,
Calamagrostis brevipilis Gray and C. longifolia Hook., may best be considered a
separate g3iius, Calamovilfa. Scribner adds a note formally describing the genus
Calamovilfa and mentions the two species, Calamovilfa brevipilis and C. longi-
folia. The first is selected as the type.
The genus differs from Calamagrostis in the chartaceous lemma,
from our species of Calamagrostis in the absence of a prolonged ra-
chilla, and from Ammophila in the more open panicles and in the
absence of the prolongation of the rachilla.
The four species are Calamovilfa brevipilis (Torr.) Scribn., in the
pine barrens from New Jersey to North Carolina; C. curtissii
(Vasey) Scribn., confined to Florida; C. longifolia (Hook.) Scribn.
(fig. 66), of the Great Plains and the dune region of Lake
Michigan; C. gigantea (Nutt.) Scribn. and Merr., also of the
Great Plains. The first two species are without creeping rhizomes;
the other two have numerous stout rhizomes and are excellent sand
binders. Calamovilfa longifolia and C. gigantea are closely re-
lated. They are differentiated by the less expanded panicle and
glabrous florets of the first and the spreading panicle, larger spike-
lets, and villous florets of the second.
Calamovilfa longifolia, the commonest species, is of some value for
forage, but is rather coarse and woody.
56. AGBOSTIS L., the bent-grasses.
Spikelets 1-flowerecl, disarticulating above the glumes, the rachilla
usually not prolonged; glumes equal or nearly so, acute, acuminate,
or sometimes awn-pointed, carinate, usually scabrous on the keel and
sometimes on the back; lemma obtuse, usually shorter and thinner in
texture than the glumes, awnless or dorsally awned, often hairy on
the callus; palea usually shorter than the lemma, 2-nerved in only
a few species, usually small and nerveless or obsolete.
Annual or usually perennial, delicate or moderately tall grasses,
with glabrous culms, flat or sometimes involute, scabrous blades, and
open or contracted panicles of small spikelets. Species about 100,
in the temperate and cold regions of the world, especially in the
Northern Hemisphere. About 25 species are found in the United
States, some of these being found also in Europe.
Type species : Agrostis stolonifera L.
Agrostis L., Sp. PI. 61, 1753; Gen. PI., ed. 5, 30. 1754. Linnaeus describes
12 species, dividing them into two groups, Aristatae and Muticae. The descrip-
tion of the genus refers to the lemma as being awned and to the presence of
a palea ("Cor. bivalvis . . . altera majore aristata"). If the type species
must agree with the description in the fifth edition of the Genera Plan-
tarum, 1 it must be chosen from the first group, Aristatae, and from those
1 See American Code of Botanical Nomenclature, Bull. Torrey Club 84 : 174. 1907. The
statement is made that "the genera of Linnseus's Species riantarum (1753) are to be
typified through the citations given in his Genera Plantarum (1754)." There is no
citation given for Agrostis and the code docs not definitely require that the genera must
be interpreted by the descriptions here given ; hence the type species may be chosen inde-
pendent of this description.
126 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. GG.Calamovilfa longifolia. Plant, X \ ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 127
species possessing a palea. Prom this standpoint the type species would be
Agrostis spica-venti, which is referred by many botanists to Apera but
which is here included in Agrostis. However, the description of Agrostis in
the fifth edition was not written by Linnauis for that edition. It was copied
f:*om the first edition, published in 1737, at which time LinnaBUs's concept of
Agrostis was chiefly based on Stipa calamagrostis. By the time the Species
Plantarum was prepared his concept of the genus Agrostis had changed, but he
did not make the corresponding change in the description in the fifth edition
of the Genera Plantarum which he prepared at the same time. It seems best,
then, to ignore this description and select the type species from the economic
species. Therefore A. stolonifera * has been selected as the type species of
Agrostis. Several of the original species are now referred to other genera:
.1. miliacea and A. paradoxa to Oryzopsis; A. arundinacea to Oalamagrostis ;
A. minima to Mibora ; A. virginica and A. indica to Sporobolus.
Vilfa Adans., Fam. PI. 2: 495. 1763. Adanson cites " Gramen canin. supin.
C. B. Theat. 12 " arid in the index, " Gramen canin. supin. minus C. B." Lin-
naeus 2 gives under Agrostis stolonifera the citation, " Gramen cariinum supinum
minus Scheuch. gram. 128." Scheuchzer 8 credits the citation to C. Bauhin.
Therefore Agrostis stolonifera L. is the type of Vilfa Adans.
Apera Adans.. Fam. PI. 2: 495. 1763. Adanson refers directly to "Agrostis 1.
Lin. Sp. 61." The first species of Agrostis described by Linnaeus in his Species
Plantarum (p. 61) is A. spica-venti, which becomes the type of Apera.
Trichodium Michx., Fl. Bor. Amer. 1: 41, pi. 8. 1803. Two species are de-
scribed, T. laxiflorum and T. decumbens. The first species, iliustiated in plate
8, is the type. This is the same as Afrostis hiemalis. Trichodium decumbens
is the same as A. perennans. Michaux distinguished the genus from Agrostis
by the absence of the palea.
Agraulus Beauv., Ess. Agrost. 5, pi. 4, f. 7. 1812. Two species, based on
Afjrostis canina L. and A. alpina Willd., are included, the first being figured and
therefore the type.
Anemagrostis Trin., Fund. Agrost. 128. 1820. Two species, based on Agrostis
spica-venti L. and A. interrupta L., are included, the first of which is taken as
the type.
Notonema Raf., Neogenyt. 4. 1825. A single s-pecies is included, Agrostis
arachnoides Ell. (A. elliottiana Schult.)
Podagrostis Scribn. and Merr., Contr. U. S. Nat. Herb. 13 : 58. 1910. Based
upon Agrostis, section Podagrostis Griseb. in Ledeb. Fl. Ross. 4: 436. 1853.
A single species, Agrostis aequivalvis Trin., referred here in each case. A. thur-
beriana Hitchc. also belongs to this group, which forms a section of Agrostis.
In Agrostis spica-venti, A. aequivalvis,. and A. thurberlana the
rachilla is prolonged behind the palea as a minute bristle or stipe,
and the lemma and palea are nearly equal and about as long as the
glumes. The palea is obsolete in many species (which have been
separated by some authors under the generic name of Trichodium),
and is much shorter than the lemma in several other species. The
awn, when present, may arise from the back of the lemma just above 1
1 See Hitchcock, Bot. Gaz. 38:141. 1904. On the basis of the specimen in the Lin-
naean Herbarium and of the synonymy, the name A. stolonifera was there applied to the
species called A. vertictllata Vill. But on reconsideration it seems best to accept the
name cis applied by Swedish botanists. Linnaeus was most familiar with the Swedish
grass, and cites as the first synonym under A. stolonifera the phrase name he had applied
to it in his Flora Suecica. He confused with this the South European species, A. ver-
ticillata, a specimen of which in his herbarium he marked " A. stolonifcra/' but we may
assume that he intended to apply the name A. stolonifera to the grass from Sweden. In
the latter work Linnaeus states that the plant is known popularly as Kryp-hwen. Dr.
Carl Lindman, who has kindly sent a series of specimens of the species in question, states
in a letter that the grass in Sweden called Krypven (the modern spelling) is the species
described by Swedish botanists as A. stolonifera. This has a long ligule, an open panicle,
and an erect culm decumbent at base or producing stolons.
2 Sp. PI. 62. 1753. 3 Agrost. 128. 1719.
128 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
the base (A. howellli Scribn.) or from about the middle (A. exarata
microphylla (Steud.) Hitchc.) or from just below the apex (A. spica-
venti, A. ellio ttiana) .
The hairs on the callus
are usually minute, but
are half as long as the
lemma in A. hallii Vasey.
Three of our species are
annuals, A. spica-venti
L., introduced from
Europe; A. exigua
Thurb., of California;
and A. ellio ttiana Schult.,
of the Southern States.
The genus furnishes
several species that are
important forage plants
either under cultivation
or in the mountain mead-
ows of the Western States.
The most important is
Agrostis palustris Huds.
(A. alba of authors 1 )
(PI. XIII; fig. 67),
known usually as redtop
because of the reddish
1 The name Agrostis alba L.
(Sp. PI. G3. 1753) is of doubtful
application. In the original
publication the name is founded
solely on the citation " Roy.
lugdb. 59 " (Royen, Flora Ley-
densis). Royen's citation of
synonym refers to Poa (appar-
ently P. nemoralis). There are
several sheets in Linnaeus's
herbarium, one of which bears
the name, Agrostis alba, in
Linnseus's script. These speci-
mens are the Agrostis alba as
generally understood, but,
FIG- 07. Redtop, Agrostis falustris. Plant, X ; spikelet, open and closed, and floret,
X 5.
Bui. 772, U. S. Dept. of Agriculture.
PLATE XIII.
REDTOP (AGROSTIS PALUSTRIS).
Bui. 772, U. S. Dept. of Agriculture.
PLATE XIV.
TIMOTHY (PHLEUM PRATENSE).
GENERA OF GRASSES OF THE UNITED STATES. 129
color of the panicle. This species is an erect plant 2 to 4 feet
high, producing rhizomes, and often decumbent at base, with flat
blades, prominent, somewhat pointed ligule, and an opeia, usually red-
dish panicle, 2 to 12 inches long, contracted in fruit, the branches in
whorls. Redtop is cultivated as a meadow and pasture grass in the
Northern States, especially upon soils lacking in lime and upon soils
too wet for timothy. In Pennsylvania and some other localities this
species is called herd's-grass.
Agrostis capillaris L. (A. tennis Sibth., A. vulgaris With., A.
alba vulgaris Thurb.), Rhode Island bent, 1 differs from red-
top in its smaller size, more delicate culms and foliage, short truncate
ligule, smaller, more open, and fewer flowered panicle, not contract-
ing after flowering. Stolons are usually absent but may be as much
as 4 to 8 inches long. Rhode Island bent is often used as a lawn
grass, especially in the Northeastern States, where the soil is lacking
in lime and bluegrass does not thrive. In some botanical works the
name Agrostis canina has been incorrectly applied to Rhode Island
bent. Agrostis canina L., a European species occasionally introduced
into the Eastern States, is a frequent constituent of the commercial
seed of creeping bent. It is called velvet bent and gives promise
of being a fine lawn grass.
Carpet bent, also called creeping bent, is a form of A. stolonifera.
This produces stolons from 1 to 4 feet long and is also used as a
lawn grass in the same region as that described for Rhode Island bent.
The seed has been imported from southern Germany.
Fiorin is a name that was applied in England to a coast form with
stoloniferous habit, long ligule, and narrow dense panicles. This
form is found along the northern Atlantic coast of Europe and
America and along the Pacific coast from British Columbia to north-
ern California. It has been called A. maritima Lam. and A. alba
mcuritima (Lam.) Meyer. It is apparently indigenous in America,
while A. capillaris and A. palmtris appear to be introductions.
Several native species of Agrostis are found in the western part of
the United States, especially in mountain meadows. One of the
commonest of the western species is A. exarata Trin., with contracted,
sometimes spikelike, panicles and awned or awnless spikelets, found
at all altitudes throughout the western portion of the United States.
according to Jackson (Index to the Linnsean Herbarium, Proc. Linn. Soc. London,
124th Sess. Suppl. 1912), these specimens were added to the herbarium after 1753 and
can not, therefore, have weight in determining the original application of the name. Lin-
naeus did not refer, under Agrostis alba, to his flora of Sweden. It would appear that he
did not intend to apply the name originally to a Swedish plant. The species usually
known as Agrostis alba- is common in Sweden, but apparently was included by Linnaeus
under A. stolonifera, to which it is closely allied. It was not until later that he applied
the name to the species as now represented in his herbarium. Under these circumstances
it seems best to drop the name Agrostis alba, as has been done by Piper (U. S. Dept. Agr.
Bull. 692, 1918) and by Stapf, as indicated in a letter to Piper.
1 See Piper, The Agricultural Species of Bent Grasses. U. S. Dept. Agr. Bull. 692. 1918
97709 19 Bull. 772 9
130 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
This is an important range grass. Common on the Pacific slope is
A. diegoensis Vasey, with creeping rhizomes, spreading panicles, and
often awned spikelets.
Two native species belonging
to the group in which the palea
is lacking are common in -the
eastern United States. Agrostis
perennam (Walt.) Tuckerm. is
a woodland species with open
panicle. Agrostis hiemalis
(Walt.) B. S. P. (fig. 68) is a
delicate open-ground species
with very diffuse capillary pani-
cle, which at maturity breaks
away from the plant as a tumble-
weed. This species, called hair-
grass and tickle grass, is found
throughout the United States.
Agrostis spica-venti L. (fig.
69), a European species, sparingly introduced in the Eastern States,
has been made the type of a distinct genus, Apera, being distinguished
by the prolongation of the rachilla and the long delicate awn from
FIG. 68. Tickle grass, Agrostis
hiemalis. Plant, X \ ', spikelet
and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES.
331
FIG. 69. Agrostis spica-venti. Plant, X I ; g^mes and floret, X 5.
132 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
just below the apex of the lemma. These characters are not deemed
sufficient to separate it from our species. The rachilla is prolonged
in A. aequivalvis and a similar awn is found in the annual A. elliot-
tiana Schult.
For a revision of the species of Agrostis found in the United States,
see Hitchcock, U. S. Dept. Agr., Bur. PL Ind. Bull. 68. 1905.
57. PHIPPSIA (Trin.) 11. Br.'
Spikelets 1-flowered, disarticulating above the glumes, the rachilla
not prolonged; glumes unequal, minute, the first sometimes wanting;
lemma thin, somewhat
keeled, 3-nerved, acute;
pa lea a little shorter
than the lemma, dentate.
A dwarf, tufted per-
ennial, with n a r r o w,
few - flowered panicles
of small spikelets. Spe-
cies one, in the arctic
regions of both hemi-
spheres; also on the al-
pine summits of Colo-
rado.
FIG. 70. Phippsia algida. Plant, X ; spikelet and
branchlet of inflorescence with the glumes of lower
spikelets remaining, and floret, all X 5.
Type species : Agrostis
Soland.
( Nlpo<f,inin s 11 b,ge n u s
Phippsia Trin., in Spreng.
Neu. Entd. 2: 37. 1821.
Phippsia R. Br., Suppl. App. Parry's Voy. 184. 1824. A single species de-
scribed, P. algida, based on Ayrostitt algida Soland.
Phippsia algida (Soland.) R. Br. (fig. TO) 'is known in the United
States only from a few localities in the alpine regions of Colorado.
It was first described as Agrostis algida by Solander. 1
58. COLEANTHUS Seidel.
Spikelets 1-flowered; glumes wanting; lemma ovate, hyaline,
terminating in a short awn ; palea broad, 2-keeled.
A dwarf annual, about an inch high, with short flat blades and
small few-flowered panicles. Species one, northern Eurasia, intro-
duced in America.
Type species: Schmidtia subtilis Tratt.
Schmidtia Tratt., Fl. Oesterr. Kaiserth. 1: 12, pi. 10, 1816, not Schmidtia
Moench, 1802. Only one species described.
Coleanthus Seidel; Roem. and Schult., Syst. Veg. 2: 276. 1817. Only one
species described, C. xubtilis, based on &clinii<Iti<t xubtilix.
i In Tliipps Voy. 200. 1810,
GENERA OF GRASSES OF THE UNITED STATES. 133
Coleanthus xuhtiUx (Tnitl.) Seidel (fig. 71), introduced from
Europe, grows on mud flats along the Columbia River, where it was
collected by Howell (on Sauvies Island, Oreg.) and by Suksdorf
(western Klickitat County, Wash.).
Mibora minima (L.) Desv. has been found at Plymouth, Mass.
This, the only species of the genus, is a low annual, differing from
Coleanthus and Phippsia in having glumes longer than the lemma,
the very small spikelets in simple spikes. Introduced from Europe.
59. CINNA L.
Spikelets 1 -flowered, disarticulting below the glumes, the rachilla
forming a stipe below the floret and produced behind the palea as a
minute bristle; glumes equal, 1-nerved; lemrria similar to the glumes,
FIG. 71. Coleanthus nubtilis. Plant, X 1 ; lemma and palea and two views of spikelet
with ripe caryopsis, X 20.
nearly as long, 3-nerved, bearing a minute, short, straight awn just
below the apex ; palea apparently 1-nerved, 1-keeled.
Tall perennial grasses, with flat blades and paniculate inflorescence.
Species three, North America and northern Eurasia, two in the
United States and one in Mexico and southward.
Type species: Cinna arundinacea L.
Cinna L., Sp. PI. 5, 1753; Gen. PI., ed. 5, 6. 1754. A single species is
described.
Abobi Arlans., Fam. PI. 2: 31, 511. 1763. Based on "Cinna Lin."
Cinnastrum Fourn., Mex. PL 2: 90. 1886. Two species are given, C. miliaceum
and ('. ])<>u<' forme, both referable to Ginna poaeformis (H. B. K.) Scribn. and
Merr.
The prolongation of the rachilla is less than 0.5 mm. in our
species, but in Cinna poaeformis of Mexico it is half as long as the
palea. The palea is 1-nerved in C. arundinacea. In C. poaeformis
the 2 nerves are close together but distinct. In C . latifolia the palea
is apparently 1-nerved, but the 2 nerves separated when the palea is
split along the keel.
134 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Cinna arundinacea (fig. 72), with somewhat contracted panicle and
spikelets 5 mm. long, grows in moist, usually shaded places in the
eastern United States; C. latifolia
(Trev.) Griseb., with open panicle
and spikelets 4 mm. long, grows in
damp woods across the continent in
the northern part of the United States,
mostly at medium and high elevations.
Both species furnish ex-
cellent forage, but are usu-
ally not abundant enough
to be of much importance.
60. LIMNODEA L. H. Dewey.
Spikelets 1-flowered,
disarticulating below the
glumes, the rachilla pro-
longed behind the palea as
a short, slender bristle;
glumes equal, firm; lemma
membranaceous. smooth,
FIG. 72. Wood reed-grass, Cinna arundinacea. , '., _ .
Plant, x i ; spikeiet and floret, x 5. nerveless, 2-tootned at the
GENERA OF GRASSES OF THE UNITED STATES.
135
apex, bearing from between the teeth a slender bent awn, twisted at
base ; palea a little shorter than the lemma.
A slender annual with flat blades and narrow panicles. Species
one, Florida to Texas.
Type species : Greenia arkansana
Nutt.
Greenia Nutt., Trans. Amer. Phil. Soc.
5: 142, 1837, not Greenea Wight and
Arn., 1834. Type O. arkansana, the only
species described.
Sclerachne Torr. ; Trin., Mem. Acad.
St. PStersb. VI. Sci. Nat. 4 1 : 273, 1841,
not Sclerachne R. Br. and Benn., 1838.
Two species are described, S. arkansana
Torr. and 8. pilosa Trin. The first,
based on Greenia arkansana Nutt., is
the type.
Thurberia Benth., Journ. Linn. Soc.
Bot. 19: 58, 1881, not Thurberia A.
Gray, 1854. Type Greenia arkansana
Nutt., the name Thurberia being substi-
tuted for Greenia.
Limnodea L. H. Dewey, Contr. U. S.
Nat. Herb. 2: 518. 1894. Only one spe-
cies described.
Limnodea arkansana
(Nutt.) L. H. Dewey
(fig. 73), has probably
no agricultural value.
A form with pilose
t
FIG. 73. Limnodea arkansana. Plant, X I ; spikelet and floret, X 5.
136 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
glumes has been named
L. arkansana pilosa (Trin.)
Scribn.
61. ALOPECURUS L., the meadow
foxtails.
Spikelets 1 -flowered, disar-
ticulating below the glumes,
strongly compressed laterally;
glumes equal, awnless, usually
united at base, ciliate on the
keel; lemma about as long
as the glumes, 5-nerved, ob-
tuse, the margins united at
base, bearing from below
the middle a slender dorsal
awn, this included or ex-
serted two or three times the
length of the spikelet; palea
wanting.
Low or moderately tall per-
ennial grasses with flat blades
and soft, dense, spikelike pan-
icles. Species about 25, in tem-
perate regions of the North-
FIG. 74. Meadow foxtail, Alopecurus pratensis. Plant, X I ; spikelet and floret, X 5.
ern Hemisphere. Of the eight North American species, two
are introductions from Europe and two are widely distributed in
GENERA OF GRASSES OF THE UNITED STATES. 137
Eurasia. Some of the European species with a distinct palea have
been segregated as the genus Colobachne.
Type species: Alopecurus pratensis L.
Alopecurus L., Sp. PI. 60, 1753; Gen. PL, ed. 5, 30. 1754. Four species are
described, A. pratensis, A. geniculatus, A. hordciformis, and A. monspeliensis.
The third and fourth species do not agree with Linnseus's generic description
and are now referred, the third to Pennisetum and the fourth to Polypogon.
The other two were well known to Linnaeus and were described in his flora of
Sweden. The first, being an economic species, is chosen as the type species of
the genus.
Alopecurus pratensis L. (fig. 74), meadow foxtail, is sometimes
used as a meadow grass in the eastern United States. It is recom
mended for mixtures on moist soil, being nutritious and producing
early forage. Meadow foxtail is an erect grass, 2 to 3 feet tall, with
short rhizomes, loose, often inflated, sheaths, and spikes or heads 2
to 4 inches long and about one-fourth of an inch thick. Introduced
from Europe, where it is favorably known as a meadow grass.
Alopecurus geniculatus L. is a low, pale, soft grass, usually 6 to 18
inches high, with decumbent rooting bases and slender panicles 1 to
3 inches long and about one-eighth of an inch thick, the delicate awn
bent and protruding about twice the length of the spikelet. Found
in moist places across the continent. An allied and more common
species, A. aristulatus Michx. (A. geniculatus aristulatus (Michx.)
Torr.), is distinguished by the scarcely exserted awns. Alopecurus
alpinus J. E. Smith (A. occidentalis Scribn.), a northern species
extending into the Rocky Mountains of the United States, has a
short, thick spike with spikelets woolly all over. Alopecurus cali-
fornicus Vasey, of the northwestern Pacific coast region, has slender
spikes, 1 to 3 inches long and one- fourth of an inch thick, the spike-
lets 3 mm. long. The species of Alopecurus are all palatable and-
nutritious, but usually are not found in sufficient abundance to be of
great importance.
62. POLYPOGON Desf.
Spikelets 1-flowered, the pedicel disarticulating a short distance
below the glumes, leaving a short-pointed callus attached; glumes
equal, entire or 2-lobed, awned from the tip or from between the
lobes, the awn slender, straight ; lemma much shorter than the glumes,
hyaline, usually bearing a slender straight awn shorter than the
awns of the glumes.
Annual or perennial usually decumbent grasses, with flat blades
and dense, bristly, spikelike panicles. Species about 10, in the tem-
perate regions of the world, chiefly in the Eastern Hemisphere, three
species being introductions into the United States.
Type species : Alopecurus monspeliensis L.
Polypogon Desf., Fl. Atlant. 1: 66. 1798. Only one species described, this
based on Alopecurus monspeliensis L.
138 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Polypogon lutosus (Poir.) Hitchc. (Agrostis lutosa Poir., P. lit
tordlis J. E. Smith, based on Agrostis littoralis With., 1796, not Lam.
1791), a perennial
with awns scarcely
longer than the
glumes, is frequent
on the Pacific coast.
Polypogon monspeli-
ensis (L.) Desf. (fig.
75) is an annual with
soft, bristly, green or
yellowish spikes 1 to
6 inches long, the
awns much longer
than the glumes.
This is a common
weed on the Pacific
coast and is occa-
sional in the Atlantic
\
FIG. 75. Polypogon monspeliensis. Plant, X I ; spikelet and floret, X 5.
States. Polypogon maritimus "Willd. is a rare species found in
Georgia and California, and differs from the preceding in having
deeply lobed lemmas, the lobes ciliate. Our species are relished by
GENEKA OF GRASSES OF THE UNITED STATES.
139
stock, and P. monspeliemis is sometimes sufficiently abundant on low
meadows to be of importance.
63. LYCURUS H. B. K.
Spikelets 1-flowered, the rachilla
articulate above the glumes; glumes
awned, the -first usually 2-awned;
lemma narrow, firm, longer than the
glumes, terminating in a slender awn.
Low perennial grasses, with dense
spikelike panicles, the spikelets borne
in pairs, the lower of the pair sterile,
the short branchlets deciduous. Spe-
cies two, in arid regions from the
southwestern United States to north-
ern South America.
Type species : Lycurus phleoides H. B. K.
Lycurus H. B. K., Nov. Gen. and Sp. 1:
141, pi. 45. 1816. Two species are described,
L. phleoides and L. phalaroides. The first
species, being figured, is chosen as the type.
Pleopogon Nutt, Journ. .Acad. Nat. Sci.
Phila. II. 1: 189. 1848. A single species,
P. setosum, is included. This is Lycurus
phleoides.
Lycuvus phleoides (fig. 76), the
only species in the United States, is a
low bunch-grass with slender erect
culms about a foot high, with a dense,
narrow, lead-color panicle 1 or 2
inches long. The species, sometimes
called Texas timothy and wolftail, is
common on the Mexican Plateau and
FIG. 76. Wolftail, Lycurus phleoides.
Plant, X 2 ; group of two spikelets,
glumes of fertile spikelet, and two
views of fertile floret, X 5.
extends north to Texas, Colorado, and Arizona. It is often an im-
portant constituent of grazing areas.
140 BULLETIN 772, IT. S. DEPARTMENT OF AGRICULTURE.
64. PHLEUM L.
Spikelets 1-flowered, laterally compressed, disarticulating above
the glumes ; glumes equal,
membranaceous, keeled,
abruptly mucronate or
awned ; lemma shorter
than the glumes, hyaline,
broadly truncate, 3 to 5
nerved; palea narrow,
nearly as long as the
lemma.
Annuals or perennials,
with erect culms, flat
blades, and dense, cylin-
dric panicles. About 10
species, in the temperate
regions of both hemi-
spheres.
Type species : Phleum pra-
tense L.
Phleum L., Sp. PI. 59, 1753 ;
Gen. PI., ed. 5, 29. 1754.
Four species are described,
P. pratense, P. alpinum, P.
arenarium, and P. schoe-
noides. The first species
is chosen as the type because
it is the only cultivated spe-
cies in the genus. The first
three species are still re-
tained in Phleum ; the fourth
is referred to Heleochloa.
Stelephuras Adans., Fam.
PI. 2: 31. 607. 1763. Based
on Phleum L.
Four species of Phleum
are found in the United
States. Our only native
species is P. alpinum L.,
mountain timothy, a per-
ennial with short spikes,
two or three times as
long as wide, found in
the northern regions of
Eurasia and America and
extending south in the
mountains of Xew Eng-
land, in the Rocky Moun-
tains to Mexico, and in
the Sierra Nevada and
Coast Ranges to the San
FIG. 77. Timothy, Phleum pratense. Plant, X i I T . ,.- .
spikelet and floret, X 5. JaCintO Mountains.
GENERA OF GRASSES OF THE UNITED STATES. 141
Mountain timothy produces a fair amount of nutritious forage,
which remains green till late in the season and is considered a valu-
able late sheep feed. It is an important constituent of mountain
meadows. This species is distinguished from common timothy by the
shorter, broader heads and by the absence of the swollen base of the
stem or so-called bulb. Two species, P. graecum Boiss. and Heldr.
and P. bellardi Willd., are annuals introduced from Europe and
found here only at a few coast points on dumping grounds for ballast.
The fourth species is timothy, PHlewn pratense L. (PL XIV; fig.
77), an erect, short-lived perennial, 2 to 4 feet tall, with elongate
cylindric inflorescences or " heads " several times longer than broad.
The stems are swollen at the base, and the glumes, like those of moun-
tain timothy, are ciliate on the keel. Timothy, a native of Europe
and northern Asia, is now commonly cultivated in this country and
in Europe as a meadow grass, and is found growing without culti-
vation in waste places, roadsides, and old fields throughout most of
the United States. It is the most important meadow grass grown in
America, and timothy hay is the standard for all grass hay sold on
the market. The region of the United States favorable for the grow-
ing of timothy is the crop area known as the cool humid region, which
includes the northeastern portion west to the Great Plains and south
to Virginia and Missouri, or farther in the mountains. Another
timothy area is found on the Pacific coast from northern California
to Puget Sound. Much timothy is grown in favorable localities in
the western mountains. In some localities timothy is known as herd's-
grass.
See Evans, U. S. Dept. Agr., Farmers' Bull. 502, 1912; McClure,
U. S. Dept. Agr., Farmers' Bull. 508, 1912; Williams, U. S. Dept.
Agr. Yearbook, 1896: 147, 1897; Scribner, U. S. Dept. Agr., Div.
Agrost. Bull. 20: fig. 47. 1900.
65. GASTRIDIUM Beauv.
Spikelets 1-flowered, the rachilla disarticulating above the glumes,
prolonged behind the palea as a minute bristle ; glumes unequal, some-
what enlarged or swollen at the base ; lemma much shorter than the
glumes, hyaline, broad, truncate, awned or awnless; palea about as
long as the lemma.
Annual grasses, with flat blades and pale, shining, spikelike pan-
icles. Species two, in the Mediterranean region ; one introduced into
the United States.
Type species : M ilium lendigerum L.
Gastridium Beauv., Ess. Agrost. 21, pi. 6, f. 6. 1812. Beauvois mentions
only one species, Milium lendigerum, but the description of the plate bears the
name Gastridium australe.
142 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Gastridium ventricosum (Gouan) Schinz and Thell. 1 (G. lendi-
gerum (L.) Gaud.) (fig. 78), with an awned lemma, a common weed
on the Pacific coast, appears
to have no economic value.
66. LAGUBUS L.
Spikelets 1-flowered, the
rachilla disarticulating above
the glumes, pilose under the
floret, produced beyond the
palea as a bristle; glumes
equal, thin, 1-nerved, villous,
gradually tapering into a
plumose aristiform point;
lemma shorter than the
glumes, thin, glabrous, bear-
ing on the back above the
middle a slender, exserted,
somewhat geniculate, dorsal
awn, the summit bifid, the
divisions delicately awn-
tipped; palea narrow, thin,
the two keels ending in
minute awns.
An annual grass, with pale,
dense, ovoid or oblong woolly
heads. Species one, in the
Mediterranean region and in-
troduced sparingly in Cali-
fornia.
Type species : Lagurus ovatus L.
Lagurus L., Sp. PL 81, 1753;
Gen. PI., ed. 5, 34. 1754. Only
one species described.
Lagurus ovatus (fig. 79) is
sometimes cultivated as an
ornamental, the woolly heads
being used for dry bouquets.
67. EPICAMPES Presl.
Spikelets 1-flowered, the
rachilla disarticulating above
1 This name is based on Agrostis
ventricosa Gouan, Hort. Monsp. 39, pi.
1, f. 2, 1762, which was published
earlier in the year than Milium lendi-
gcrum L., Sp. PI., ed. 2, 91, 1762, as
shown by Linnaeus's reference to
Gouan's work in the preface to the sec-
ond edition of his Species Plantarum.
FIG. 78. Gastridium vcntricosum. Plant, X
spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES.
143
the glumes; glumes about equal; lemma equaling or longer than the
glumes, 3-nerved, often bearing a slender awn just below the tip.
FIG. 79. Hare's-tail grass, Lagurus ovatus. Plant, X I ; spikelet and floret, X 5.
Tall cespitose perennials, with open, narrow, or spikelike panicles.
Species 15, northern South America to Mexico, 5 extending into the
southwestern United States.
144 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Type species : Epicampes strictus Presl.
Epicampes Presl, Rel. Haenk. 1: 235, pi. 39. 1830. Only one species de-
scribed.
Crypsinna Fourn., Mex. PI. 2: 90. 1SS6. Three species are mentioned,
C. stricta, C. macroura, and C. setifolia. In the generic description the panicle
is said to be densely
spiciform. This applies
best to the second spe-
cies, C. macroura, which
is chosen as the type.
One species, Epi-
campes rigens Benth.
(fig. 80), with long,
slender, cylindric,
pale, spikelike pan-
icles, the glumes
shorter than the
lemma, is found from
western Texas to
southern California.
This species, called
deer-grass, and the
four other species, E.
ligulata Scribn., E.
berlandieri Fourn., E.
subpatens Hitchc., 1
and E. emersleyi
1 Epicampes subpatens, n. sp.
Culms erect, glabrous, 50
to 100 cm. tall ; sheaths
glabrous, slightly scabrous,
compressed-keeled, especially
those of the innovations ;
ligule softly membranace-
ous, 1 to 2 cm. long ; blades
flat or folded, scabrous, 1
to 3 mm. wide, the lower
as much as 50 cm. long ;
panicles narrow but rather
loose, mostly 20 to 40 cm.
long, the branches ascend-
ing, more or less fascicled
or whorled, naked below ;
spikelets about 3 mm. long,
FIG. 80. Deer-grass, Epicampes ricfcns. Plant, X I ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 145
(Vasey) Hitchc. (Muhlenbergia emersleyi Yasey, M. vaseyana
Scribn.) , are forage grasses. A Mexican species, E. macrowa Benth.,
is of considerable economic importance, the roots being used in the
manufacture of scrubbing brushes.
68. MUHLENBEBGIA Schreb.
Spikelets 1-flowered, the rachilla disarticulating above the glumes;
glumes usually shorter than the lemma, obtuse to acuminate or
awned, the first sometimes small or rarely obsolete; lemma firm-
membranaceous, 3 to 5 nerved, with a very short, usually minutely
pilose callus, the apex acute, sometimes bidentate, extending into a
straight or flexuous awn, or sometimes only mucronate.
Perennial or rarely annual low or moderately tall grasses, tufted
or rhizomatous, the culms simple or much branched, the in-
florescence a narrow or open panicle. Species about 80, mostly in
Mexico and the southwestern United States, a few in the eastern part
of the Old World ; 40 species in the United States.
Type species: Muhlenbergia schreberi Gmel.
Muhlenbergia Gmel., Syst. Nat. 2 : 171. 1791. Only one species mentioned.
Dilepyrum Michx., Fl. Bar. Amer. 1 : 40. 1803. ' Two species are described,
D. urixtomun, which is Brachyelytrum erectum, and D. minutiflorum, which is
MuMenbergfa schreberi Gmel. They are equally eligible as the type. The
second is chosen, in order to conserve the generic name Brachyelytrum.
Podosemum Desv., Nouv. Bull. Soc. Philom. Paris 2 : 188. 1810. The type is
Stipa capillaris Lam. (P. capillaris Desv.), the only species mentioned.
Olomena Beauv., Ess. Agrost. 28, pi. 7, f. 10. 1812. The type is C. peruviana,
the only species mentioned. This is Muhlenbergia peruviana (Beauv.) Steud.
Trichochloa Beauv., Ess. Agrost. 29, pi. 8, f. 2. 1812. The type and only
species is T. purpurea. This has not been identified. Roemer and Schultes
say it is Trichochloa expansa DC. (Muhlenbergia expanse (DC.) Trin.).
Tosagris Beauv., Ess. Agrost. 29, pi. 8, f. 3. 1812. The type is T. agrostidea,
the only species mentioned. This has not been identified, but it appears to be
a species of Muhlenbergia.
Sericrostis Raf., Neogenyt. 4. 1825. "Type Stipa sericea MX. or diffusa
Walter." This is Muhlenbergia capillaris (Lam.) Trin.
Calycodon Nutt, Journ. Acad. Phila. II. 1: 186. 1848. The type is C. mon-
tanum (Muhlenbergia montana Hitchc.), the only species described.
Vaseya .Thurb., in Gray, Proc. Acad. Phila. 1863 : 79. 1863. The type is
V. comata Thurb., the only species described. This is Muhlenbergia andina
(Nutt.) Hitchc. (Calamag'rostis andina Nutt).
often tinged with purple ; glumes about as long as the lemma, papery, acutish,
scabrous ; lemma narrowed and scabrous abovo, villous below, awnless, or occasionally
those of a few of the spikelets with a flexuous awn about 1 cm. long.
Type, U. S. National Herbarium no. 905799, collected in a rocky ravine, Guadeloupe
Mountains, near Queen, N. Mex., altitude 7,000 feet, Sept. 5, 1915, by A. S. Hitchcock,
no. 13541.
This species is closely allied to Epicampes emersleyi, from which it differs in the awn-
less spikelets and larger, looser, and more spreading panicles. The writer examined the
two forms in the Guadeloupe Mountains, southern New Mexico, and concluded from these
field observations that the awned and awnless forms represented two distinct but closely
allied species. The delicate awns are not noticeable at a distance but the more open
panicle was always found to be associated with the awnless spikelets.
Other specimens in the U. S. National Herbarium. TEXAS : Limpia Canyon, Nealley
133. Chisas Mountains, Bailey 392. Guadeloupe Mountains, Bailey 739. Western Texas,
Wright 729. NEW MEXICO : Socorro, Plank 53. Silver City, Greene 439. ARIZONA :
Patagonia, Hitchcock 3719. Chiracahua Mountains, Tourney 15a. Santa Catalina Moun-
tains, Griffiths 7149.
1 Syst. Veg. 2 : 384. 1817.
97769 19 Bull. 772 10
146 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Chaboissnea Fourn., Mex. PI. 2: 112. 1886. A single species, C. ligulata, is
included. This is Muhlenbergia ligulata (Fourn.) Scribn. and Merr.
Muhlenbergia is a somewhat artificial genus, including species of
very diverse habit. It differs from Sporobolus in the 3-nerved awned
or mucronate lemma, and from Agrostis in the firmer lemma, usually
longer than the glumes. One group, including M. squarrosa (Trin.)
Rydb. (fig. 81), M. repens (Presl) Hitchc., and their allies, has been
usually referred to Sporobolus. The species of this group are in-
cluded in Muhlenbergia because of the 3-nerved mucronate or awned
lemmas, but they form a distinct section or possibly a distinct genus.
FIG. 81. Muhlenbergia, squarrosa. Plant, X \ ; spikelet and floret, X 5.
In M. repens the lateral nerves of the lemma are commonly obsolete,
and the apex is sometimes scarcely mucronate.
Of the species found in the United States two are annuals, M. de-
pauperata Scribn., with acuminate or awned glumes, and M. micro-
sperma (DC.) Kunth, with obtuse glumes, both growing in the ex-
treme Southwest. The latter species produces cleistogenes in the axils
of the lower sheaths. Muhleiibergia mexicana (L.) Trin. and its
allies have branching stems and numerous panicles. The glumes are
GENERA OF GRASSES OF THE UNITED STATES.
147
reduced in M. schreberi (fig. 82), the type species, the first being
obsolete and the second not over 0.5 mm. long. In M. montana
(Nutt.) Hitchc. (Calycodon montanum Nutt ; Muhleribergia trifida
Hack. ; M. gradlis
of authors, not
H. B.K.) the sec-
ond glume is 3-
toothed. Muhlen-
bergia capillaris
(Lam.) Trin. (fig.
83), of the South-
ern States, is a
handsome peren-
nial with diffuse
purple panicles.
There are nine
species in the
Eastern States;
the others are
western or mainly
southwestern.
Many of the west-
ern species are
important range
grasses and often
form a consider-
able proportion of
the grass flora of
the arid and semi-
arid regions. The
commonest of
these are M. mon-
tana and M.
wrightii V a s e y.
The second has a
spikelike leaden-
hued panicle.
FIG. 82. Nimble Will, Muhlenbergia schreberi. Plant, X I ; branchlet showing both first
ana second glumes of two spikelets, spikelet with obsolete first glume, and floret, all
X 5.
148 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 83. Muhlenbergia capillaris. Plant, X I ; spikelet, X 5.
GENERA OF GRASSES OF THE UNITED STATES.
149
69. SPOROBOLUS R. Br.
Spikelets 1-flowered, the rachilla disarticulating above the glumes;
glumes awnless, usually unequal, the second often as long as the spike-
let; lemma membranaceous, 1-nerved,
awnless; palea usually prominent and
as long as the lemma or longer; seed
free from the pericarp.
Annual or perennial grasses, with
small spikelets in open or contracted
PIG. 84. Smut-grass, Sporobolus berteroanus. Plant, X i ; spikelet and floret, X 5.
150 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
panicles. Species about 95, in the warm regions of both hemispheres,
most abundant in America ; 36 species in the United States.
Type species : Agrostis indica L.
Sporobolus R. Br., Proclr. Fl. Nov. Holl. 169. 1810. Three species are de-
scribed, & indicus, 8. elongatus, and 8. pulchellus. Brown states that Sporobo-
lus includes Agrostis species of Linnaeus. Of the three species described by
Brown only the first was known to Linnaeus and included by him under Agrostis.
Hence the first species is chosen as the type.
Agrosticula Raddi, Agrost. Bras. 33, pi. 1, f. 2. 1823. Type A. muralis, the
only species described.
Bennetia Raf., Bull. Bot. Seringe 1: 220. 1830. Afirostis jmicea Michx. is
the only species included. This is Sporobolus gracilis (Trin.) Merr.
Crystostachys Stend.. Syn. PI. Glum. 1: 181. 1854. The type is C. rapinata.
the only species described. From the description this appears to be Sporobolus
vaginaeflorus.
Bauchea Fourn.. Mex. PI. 2: 87. 1886. Type B. karwinskyi, the only species
described. This is Sporobolus u:rightii.
The fruit is free from the lemma and palea, and falls readily from
the spikelet at maturity. Because of this character the species have
been called drop-seed grasses. The genus differs from Muhlenbergia
in having 1 -nerved awnless lemmas and from Agrostis in having
lemmas as long as the glumes or longer and as firm.
Four species of the United States are annual. One of them,
Sporobolus vaginae-flams (Torr.) Wood, is called poverty grass,
because it grows in sterile soil. This has narrow panicles, partly or
wholl}' inclosed in the sheaths. Several of the perennial species have
creeping rhizomes. One of these, S. virginicus (L.) Kunth, is a
common seashore grass in the Southern States. It has erect stems
6 to 10 inches tall, with spikelike panicles of pale spikelets. The
other species of the genus are erect bunch-grasses. Sporobolus ~ber-
teroanus (Trin.) Hitchc. and Chase (fig. 84), with long, slender,
spikelike panicles, is common in the Southern States (S. indicus
of the manuals, not S. indicus (L.) R. Br.). This species is
called smut-grass, because the inflorescence is frequently affected
with a black fungus. The glumes are about equal and much
shorter than the lemma. Sporobolus wyptandrus (Torr.) Gray
(fig. 85) is common on sandy soil, especially in the interior of
the country. This has very small spikelets in panicles sometimes
partly inclosed in the upper sheath, only the upper portion
spreading, or even entirely inclosed in the swollen sheaths. There
is a conspicuous tuft of hairs at the summit of the sheaths. In
winter the leaves and stems become fibrous and much frayed out by
the wind.
Two species of the Southwest are important forage grasses in the
arid and semiarid regions. Sporobolus cdroides Torr. (fig. 86),
growing in dense, tough clumps, the stems 1 or 2 feet high, and with
large spreading panicles, is found on somewhat alkaline soil and is
called bunch-grass or alkali saccaton. It ranges from Nebraska to
GENERA OF GRASSES OF THE UNITED STATES.
151
Montana and Texas. Sporobolus wrigJitii Munro, saccaton , is much
taller, with a large but narrow panicle. This is found from Arizona
to western Texas.
Most of the per-
ennial species of
Sporobolus are pal-
atable forage,
grasses, but few 7 of
them are abundant
enough to be of im-
portance. On the
Arizona Plateau, S.
interruptus Vasey
is an important
range grass. It is
called black sporo-
bolus, because of
the dark, narrow,
loosely flowered
panicle.
70, BLEPHARONETJKON
Nash.
Spikelets 1 -flow-
ered, the rachilla
disarticu lating*
above the glumes;
glumes subequal,
rather broad;
lemma 3-nerved,
the nerves densely
pilose ; palea
densely pilose be-
tween the two
nerves.
A perennial grass
with an open, nar-
row panicle. Spe-
cies one ; southwest-
ern United States
and northern Mex-
ico.
Type species: Vilfa
tricholcpis Torr.
Blepharo neuron
Nash, Bull. Torrey
Club 25: 88. 1898.
Only one species men-
tioned, B tricholepiS FIG. 85. Saud dropseed, Nporo&oZus cryptandrus. Plant,
(Tor.) Nash. X i; spikelet and floret, the palea splitting, X 5.
152 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 86 Alkali saccaton, Sporobolus air&ides. Plant, X I ; spikelet and floret, X 5.
GENERA OP GRASSES OF THE UNITED STATES.
153
The single species (fig. 87) is a tufted grass about a foot high,
found on open or rocky soil at middle altitudes from Colorado to
central Mexico. It is a palatable grass, sufficiently abundant in places
to be of importance. Until recent
years the species was included in
Sporobolus.
71. CKYPSIS Ait.
Spikelets 1 -flowered, the rachilla
disarticulating below the glumes;
glumes about equal, narrow, acute;
lemma broad, thin, awnless; palea
similar to the lemma, about as long,
2-nerved, readily splitting between
the nerves; fruit a utricle, the seed
free from the thin pericarp.
A spreading annual, with capitate
inflorescences in the axils of broad
bracts, these being enlarged sheaths
with short rigid blades. Species
one, in the Mediterranean region;
sparingly introduced into the United
States.
Type species: Schoenus aculeatus L.
Crypsis Ait., Hort. Kew. 1: 48. 1789.
A single species is mentioned, with two
varieties or forms, a (the equivalent of
the species), based on Schoenus aculeatus
L., and j3, based on Phlewm schoenoides
L. The first is the type.
Bentham and Hooker 1 state
that the spikelet has four
glumes and no palea. Hackel 2
states that the palea is 1-nerved.
Our specimens show an evi-
dently 2-nerved palea.
FIG. 87. Blepharoneuron tricholepis. riant, X I ; spike-
let and floret, X 5.
'Gen. PI. 8: 1139. 1883.
2 Engl. and Prantl, Pflanzenfam. 2 2 : 48. 1887 J _
154 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Crypsie acufoafa. (L.) Ait. (fig. 88) has been introduced in a few
places in California.
72. HELEOCHLOA Host.
Spikelets 1 -flowered, the rachilla disarticulating above the glumes;
glumes about equal, narrow, acute; lemma broader, thin, a little
longer than the glumes ; palea nearly as long as the lemma, 2-nerved,
readily splitting between the nerves ; caryopsis free from the lemma
and palea.
Low perennial spreading grasses, with oblong, dense, spikelike
panicles, terminal and on short lateral branches, the subtending leaves
FIG. 88. Crypsis aculeata. Plant, X I ; spikelct and floret, the palea splitting, X 5.
with inflated sheaths and reduced blades. Species about seven, in
the Mediterranean region, one introduced into the United States.
Type species : Heleochloa alopecuroides Host.
Heleochloa Host, Gram. Austr. 1: 23. 1801. Two species are described,
H. alopecuroicles and H. schoenoidcx, both of which are figured. The first is
chosen as the type.
Heleochloa schoenoides (L.) Host (fig. 89) has been introduced
into the eastern United States at several points from Massachusetts
and Delaware to Illinois.
73. BBACHYEJLYTBUM Beauv.
Spikelets 1 -flowered, the rachilla disarticulating above the glumes,
prolonged behind the palea as a slender naked bristle; glumes very
short, unequal, the first sometimes obsolete, the second sometimes
awned ; lemma firm, narrow, 5-nerved, the base extending into a pro-
GENERA OF GRASSES OF THE UNITED STATES. 155
nounced oblique callus, the apex terminating in a long straight
scabrous awn.
Perennial erect, slender grasses, with short knotty rhizomes, flat
blades and narrow, rather few-flowered panicles. Species one, North
American.
\
FIG. 89. Heleochloa schoenoides. Plant, X I ', spikelet and floret, the palea splitting, X 5.
Type species: Muhlenbergia erecta Schreb.
I.nichyelytrum Beauv., Ess. Ajri-ost. .">!>. pi. 9, f. 2. 1812. The type is the
figured species, B. erectum, based 011 Huhlenberyia erecta.
156 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Brachyelytrum erectum (Schreb.) Beauv. (fig. 90), found in
rich rocky woods in the northeastern quarter of the United States, is
of no economic importance. It has been known also as B. aristatum
Beauv.
74. MILIUM L.
Spikelets 1-flowered, disarticulating above the glumes; glumes
equal, obtuse, membranaceous, rounded on the back; lemma a little
shorter than the glumes, obtuse, awnless, obscurely nerved, rounded
on the back, dorsally compressed, in fruit becoming indurate, smooth,
and shining, the margins inclosing the lemma, as in Panicum.
Moderately tall grasses with flat blades and open panicloe. Spe-
cies about six, in- the cooler parts of Eurasia, one of which is found
also in northeastern North America.
Type species: Milium effusum L.
Milium L., Sp. PI. 61, 1753; Gen. PI., ed. 5, 30. 1754. Two species are de-
scribed, M. effusum and M. confertum. The first species is chosen as the type
as it was the one best known to Linnaeus, being described in his flora of Sweden.
The second species is now reduced to a variety of M. effusum. Milium is an
ancient Latin name for the common millet of Europe (Panicum miliaceum L. ).
Linnaeus applied this name to the genus above described. 1
Milium effusum L. (fig. 91) , millet grass, the only representative of
the genus in America, is a slender erect perennial 3 to 4 feet tall,
found in cool woods from Nova Scotia to Illinois. It is of no
economic importance.
75. ORYZOPSIS Michx.
Spikelets 1-flowered, disarticulating above the glumes; glumes
about equal, obtuse or acuminate; lemma indurate, usually about as
long as the glumes, broad, oval or oblong, nearly terete, usually
pubescent, with a short, blunt, oblique callus, and a short, deciduous,
sometimes bent and twisted awn ; palea inclosed by the edges of the
lemma.
Perennial, mostly low grasses, with flat or often involute blades
and terminal narrow or open panicles. Species about 20, in the north
temperate regions of both hemispheres; 13 species in the United
States.
Type species: Oryzopsis asperifolia Michx. (fig. 92).
Oryzopsis Michx., Fl. Bor. Amer. 1 : 51. 1803. A single species described.
Dilepyrum Raf., Med. Repos. 5: 351. 1808. Rafinesque here announces a new
work and gives the names of several proposed new genera and species. One of
these is "Dilepyrum, the Orizopsis of do [Michaux]." The type, then, is Ory-
zopsis asperifolia Michx.
Piptatherum Beauv., Ess. Agrost. 17. pi. 5, f. 10. 1812. Beauvpis mentions
five species and figures two, P. coerulescens and P. punctatum. Milium coerules-
cens, the basis of the first species, is chosen as the type.
Eriocoma Nutt., Gen. PI. 1: 40. 1818. The type is E. cuspidata Nutt., the
only species described. This is the same as Oryzopsis liymenoides.
1 For a discussion of Milium and Panicum, see Hitchcock and Chase, Contr. U. S. Nat.
Herb. 15: 11. 1910.
GENERA OF GRASSES OF THE UNITED STATES. 157
FIG. 90. Brachyelytrum erectum. Plant, X 1 ; branchlet, with glumes of two spikelets,
and floret, X 5.
158 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Urachne Trin., Fund. Agrost. 109. 1820. Trinius cites Beauvois's two figures
mentioned above, which represent Piptatherum coerulescens and P. punctatum,
and at the end of his generic description lists three species, U. coerulescens
(M ilium coerulescens Desf.), U. rircscens
(Milium paradoxum Scop.), and U. parviflora
(Agrostis miliacca L.). The first of these is
chosen as the type.
Fendlera Steud., Syn. PI. Glum. 1 : 419. 1854.
Type, F. rhynclielytroides Steud., the only
species described. This is the same as Ory-
zopsis hymenoides.
The commonest species is Oryzopsis
hymenoides (Roem. and Schult.)
Kicker, found throughout the region
west of the Rocky Mountains on dry
soil. This has an open divaricate pani-
cle and densely long-silky lemmas.
The species of Oryzopsis are grazed by
stock, but usually are not in suffi-
cient abundance to be of impor-
tance, except Indian mountain
rice (O. hynwnoides) .
The allied Mexican and South
American genera, Nasella Desv.
and Piptochaetium Presl, differ in
having an obliquely obovate fer-
tile lemma, the apex gibbous, and
the awn eccentrically attached.
76. STIPA L., the spear-grasses.
Spikelets 1-flowered, disarticu-
lating above the glumes, the artic-
ulation oblique, leaving a .bearded,
sharp-pointed callus attached to
the base of the floret ; glumes mem-
branaceous, often papery, acute,
FIG. 91. Millet grass, Milium effusum. Plant, X \ ', spikelet and floret, X 5.
acuminate or even aristate, usually long and narrow ; lemma narrow,
terete, firm or indurate, strongly convolute, terminating in a usually
bent and twisted, prominent, persistent awn; palea inclosed in the
convolute lemma.
GENERA OF GRASSES OF THE UNITED STATES. 159
Perennial grasses, with usually convolute blades and narrow pan-
icles. Species about 100, in the temperate regions of the world,
especially on plains and steppes; 30 species in the United States,
mostly in the western part.
Type species : Stipa pennata L.
Stipa L., Sp. 1M. 78, 1753 ; Gen. PI., ed. 5, 34. 1754. Limireus describes three
species, . pennata, 8. juncea, and S. avenacca. The first two are from central
and southern Europe, the third from Virginia. The first species is selected as
the type.
160 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Podopogon Raf., Neogenyt. 4. 1825. Two names are given, " Stipa avenacea
L. and " barbatu " Michx., both belonging to the same species.
Fie. 93. Porcupine grass, Stipa spartea. Plant, X 1 ; glumes and floret, X 2.
GENERA OF GRASSES OF THE UNITED STATES. 161
Some of the western species have plumose or feathery awns, those
of Stipa neo-mexicana (Thurb.) Scribn. being 4 to 8 inches long,
plumose to the second bend, those of the handsome S. speciosa Trin.
and Kupr. plumose below the single bend. A striking species of the
upper Mississippi Valley is Stipa spartea Trin. (fig. 93), called
porcupine grass and devil's darning needles. The rigid indurate
fruiting lemma is about three-fourths of an inch long, tapering be-
low into a very sharp hairy point, which acts like a barb, and termi-
nating above in a stout awn as much as 6 inches long. At maturity
the awn bends twice near the middle and becomes tightly twisted be-
low the first bend. Variations in moisture cause the awn to twist
and untwist, by which movement and by the aid of the sharp callus
it can penetrate the soil. Several other species have elongate awns,
such as S. avenacea L. of the eastern half of the United States and S.
comata Trin. and Rupr. of the western half, the latter species being
called needle-and-thread grass, because of the long flexuous upper
portion of the awns. /Stipa viridula Trin. and its allies have a nar-
row compact panicle and comparatively inconspicuous awns 1 or 2
inches long. One of these species, S. vaseyi Scribn., is called sleepy
grass, because of the narcotic effects sometimes produced upon horses
when they have fed upon it. Sleepy grass, found in New Mexico
and Colorado, is a stout grass 3 to 5 feet high, with a narrow panicle
as much as a foot long, the sheaths hairy at the throat. In S. tenuis-
sima Trin. (fig. 94) of New Mexico the fruit is very small, less than
3 mm. long.
The species of Stipa are for the most part valuable forage plants.
The most important species on the ranges are S. viridula, S. minor
(Vasey) Scribn., and & lettermani Vasey. They are known as porcu-
pine grasses. All have narrow panicles. One of the Old World
species, S. tenacissima L., furnishes a part of the esparto or alfa
grass of Spain and Algeria that is used in the manufacture of paper
and cordage.
77. AEISTIDA L., the needle grasses.
Spikelets 1 -flowered, the rachilla disarticulating obliquely above
the glumes; glumes equal or unequal, narrow, acute, acuminate, or
awn-tipped ; lemma indurate, narrow, terete, convolute, with a hard,
sharp-pointed, usually minutely bearded callus at base, terminating
above in a usually trifid awn.
Annual or perennial, mostly low grasses, with narrow, frequently
convolute blades and narrow or sometimes open panicles. Species
about 150, in the warmer regions of the world; 36 species in the
United States ; especially abundant in the Southwestern States,
97769 19 Bull. 772 11
162 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 94. Stipa tenuissima. Plant, X I ; spikelet, X 2 ; glumes and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 163
Type species : Aristida adscensionis L.
Aristida L., Sp. PI. 82, 1753; Gen. PI., ed. 5, 35. 1754. A single species is
described.
Streptachne R. Br., Prodr. Fl. Nov. Holl. 174. 1810. A single species, 8.
stipoides, is included. In this the lateral awns are obsolete.
Chaetaria Beauv., Ess. Agrost. 30, pi. 8, f. 5, 6. 1812. Twenty-five species
are listed, two, C. stricta (based on Ari-stida stricta Michx.) and C. capillaris,
are illustrated. Aristida stricta (fig. 5) is taken as the type.
Curtopogon Beauv., Ess. Agrost. 32, 159, pi. 8, f. 7. 1812. The only species
included is based on Aristida dichotoma L.
Trixostis Rat, Bull. Bot. Seringe 1: 221. 1830. A single species, "Aristida,
gracilis" [Ell.], is included.
Moulinsia Raf., Bull. Bot. Seringe 1: 221. 1830. A single species, "Aristida
lanosa " Muhl., is included.
Ortachne Nees, in Seeman, Bot. Voy. Herald 225. 1857. A single species,
based on Streptachne pilosa H. B. K., is included.
In one group of the genus the lateral awns are reduced to mere
points or are entirely absent. Two species of this group (section
Streptachne) are found in Arizona, Aristida scabra (H. B. K.) Kunth,
with a curved but not twisted awn, and A. schiedeanaTr'm. andRupr.,
with a twisted awn. The former is found also in southern Florida.
In three species the awn is articulate at base, A. desmantha Trin.
and Rupr., with short neck, A. tuberculosa Nutt., an annual with a
slender, twisted neck, and A. calif omica Thurb., a perennial with a
slender, twisted neck. Aristida dichotoma Michx., a small annual
with a coiled central awn, is common in the Eastern States. Two
other annuals are common in the eastern part of our country, A. gra-
cilis Ell., with the central spreading or reflexed awn less than half
an inch long, and A. oligantha Michx. (fig. 95), with awns 2 or 3
inches long. The type species, A. adscensionis L. (A. bromoides
H. B. K.), has a wide distribution in warm countries and extends
into the southwestern United States. This is a low annual, usually
much branched at base, with contracted panicle, the first glume about
half as long as the second, and awns about one-third of an inch long.
A common perennial species in the semiarid regions of the West is
A. longiseta Steud., called dog-town grass, because it is especially
abundant on the new soil of prairie-dog communities. Aristida fend-
leriana Steud. is an allied species of the same region. The first has
a long second glume, about four-fifths of an inch long, and awns as
much as 3 or 4 inches long. The second has a shorter second glume,
about three-fifths of an inch long, and awns less than 2 inches long,
and grows in dense tufts with curly leaves crowded at the base of
the plant. Aristida purpurea Nutt. differs in having slender curved
pedicels. These species are troublesome when the fruit is ripe, be-
cause this with its spreading awns becomes detached at maturity and
is blown about by the wind. These fruits are sometimes scattered
in vast quantities, the wind hurling them across the plains with the
sharp-pointed callus in advance. They work their way into the
wool of sheep and into the nostrils and eyes of all classes of stock.
164 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 95. Needle grass, Aristida oligantha. Plant, X i ; glumes and floret, X 2.
GENERA OF GRASSES OF THE UNITED STATES. 165
The species of Aristida are of distinctly minor importance for for-
age except in the Southwest, where several species, such as A. longi-
seta, are eaten by stock before the flowers are produced. The annual
species of the Eastern States are often found on open sterile soil,
and hence are called poverty grass, a name applied also to annuals of
other genera.
6. NAZIEAE, THE CURLY-MESQUITE TRIBE.
78. NAZIA Adans.
(Tragus Hall.)
Spikelets 1 -flowered, in small spikes of 2 to 5, the spikes sub-
sessile, falling entire, the spikelets sessile on a very short zigzag rachis,
the first glumes small, thin, or wanting, appressed to the rachis, the
second glumes of the two lower spikelets strongly convex with 3
thick nerves bearing a row of squarrose, stout hooked prickles along
each side, the two second glumes forming the halves of a little bur,
the upper 1 to 3 spikelets reduced and sterile ; lemmas and palea thin,
the lemma flat, the palea strongly convex.
Low annual grasses, with flat blades and terminal inflorescence, the
burs or spikes rather closely arranged along an elongate, slender axis.
Species three, in the tropical regions of both hemispheres ; two species
being introduced in the southern United States.
Type species: Cenchrus racemosus L.
Nazia Adans., Fam. PI. 2: 581. 1763. The genus is based on Cenchrus
racemosus L.
Trains Hall., Stirp. Helv. 2: 203. 1768. Haller cites pre-Linnsean authors
who connect Tragus with Cenchrus racemosus L.
Lappago Schreb., Gen. PI. 55. 1789. A new name is proposed for Tragus
Hall.
Echisachys Neck., Elem. 3: 228. 1790. No species are given. The author
cites " Cenchrus Lin.," but his description shows that it is Linnseus's first species,
Cenchrus racemosus, that he is renaming.
Nazia racemosa (L.) Kuntze, with 3 to 5 spikelets in each cluster,
the lower about 4 mm. long, is found in open ground from Texas to
Arizona, and N. aliena (Spreng.) Scribn. (fig. 96), with two spike-
lets in each cluster, the lower 2 to 3 mm. long, here and there through
the Southern States to Arizona. They are somewhat weedy grasses
of no economic importance.
79. OSTEBDAMIA Neck.
(Zoysia Willd.)
Spikelets 1 -flowered, laterally compressed, appressed flatwise
against the slender rachis, glabrous, disarticulating below the glumes;
first glume wanting; second glume coriaceous, mucronate, or short-,
awned, completely infolding the thin lemma and palea, the palea
sometimes obsolete*
166 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Perennial low grasses with creeping rhizomes, short, pungently
pointed blades, and terminal spikelike racemes, the spikelets on short
appressed pedicels. Species about five, southeastern Asia to New
Zealand.
Type species: Agrostis matrella L.
Osterdamia Neck., Elem. Bot. 3: 218. 1790. In a note appended to the para-
graph on Agrostis, Necker states, "Agrostis matrella Lin. species distincta,
agrostidis proxima, quam osterdamiam appellamus, char-
actere sequenti." Although Osterdamia, Agrostis, Milium, and
many other groups are called by Necker species of his genus
Achyrophyton, these so-called species are the equivalent of
the genera of his contemporaries and are usually so recog-
nized by botanical writers.
Zoysia Willcl., Ges. Naturf. Freund. Berlin, Neue Schrift. 3:
440. 1801. Type and only species, Z. pun (/ens Willd.
Matrella Pers., Syn. PI. 1: 73. 1805. Type species. Affront!*
juncca Lam., the only species described.
Several years ago a species
of this genus was introduced
into the United States as a
lawn grass under the names
Korean lawn grass and Jap-
anese lawn grass. It AT as
recommended for the South-
ern States and was said to be
hardy as far north as Connecti-
cut. 1 The species then intro-
FIG. 96. Nazia aliena. Plant, X I ; group of spikelets (spike) and single spikelet, X 5.
duced appears to be Osterdamia japonica (Steud.) Hitchc. (Zoysia
japonica Steud.). Recently a fine-leaved species, Osterdamia tenui-
folia (Willd.) Kuntze, has been introduced into Florida and has
given favorable results. The original species, 0. matrella (L.)
Kuntze (fig. 97), manila grass, is common in the Philippine Islands.
1 Scribner, U. S. Dept. Agr., Div. Agrost. Bull. 3: 95. 1896.
GENERA OF GRASSES OF THE UNITED STATES. 167
80. HILAEIA H. B. K.
Spikelets sessile, in groups of 3, the groups falling from the
axis entire, the central spikelet (next the axis) fertile, 1-flowered, the
2 lateral spikelets staminate, 2-flowered ; glumes coriaceous, those of
the 3 spikelets forming a false involucre, in some species connate
at the base, more or less asymmetric, usually bearing an awn on
FIG. 97. Manila grass, Osterdamia matrella. Plant, X I ; spikelet, X 10 ; floret with
caryopsis, the palea obsolete, X 10.
one side from about the middle; lemma and palea hyaline, about
equal in length.
Perennial low grasses, the groups of spikelets appressed to the
axis, in terminal spikes. Species five, in arid regions, southwestern
United States to Central America, all but one found within the limits
of the United States.
Type species: Hilaria cenchroides H. B. K.
Hilaria H. B. K., Nov. Gen. and Sp. 1 : 116. 1816. Only one species described.
168 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Pleuraphis Torr., Ann. Lye. N. Y. 1: 148, pi. 10. 1824. Type species P.
jamesii Torr., the only one described.
Hexarrhena Presl, Rel. Haenk. 1: 326, pi. 45. 1830. Type species H. cen-
chroides Presl, the only one described. This is the same as Hilaria cen-
chroides.
FIG. 98. Curly mesquite, Hilaria belangeri. Plant, X 1 ; single spike, X 1 ; group of
spikelets seen from front or outside, showing staminate spikelets in front and top of
fertile spikelet behind, X 5 ; same group from behind or next the axis, showing the
fertile spikelet in front and the two staminate spikelets behind, X 5 ; fertile spikelet
as seen from the inside, X 5 ; fertile floret, X 5 ; staminate spikelet, X 5.
Schleropelta Buckl., Prel. Rep. Geol. and Agr. Surv. Tex. App. 1. 1866. A
single species is included, S. stolonifera Buckl., which is the same as Hilaria
lelangeri Steud.
Hilaria belangeri Steud. (fig. 98) is a common grass on the Great
Plains of Texas and northern Mexico. In Texas it is called curly
GENERA OF GRASSES OF THE UNITED STATES. 169
mesquite. It is a low grass, forming wiry stolons that in favorable
soil produce a close, firm sod. The flowering culms are a few inches
high and terminate in a short spike. Curly mesquite is an important
grazing grass of the uplands of Texas. Our species has commonly
been referred to the related, H. cenchroides^ of Mexico.
Hilaria jamesii (Torr.) Benth. (fig. 99), an erect grass about a
foot high, with glumes narrowed above, is found from Wyoming to
Texas and southern California. This is called galleta grass in New
Mexico. HUaria mutica (Buckl.) Benth., found from Texas to Ari-
zona, differs from the preceding in having some of the glumes broad-
ened above. This species is sometimes called tobosa grass. Hilaria
rigida (Thurb.) Benth., with felty pubescent branched culms, is
found from Utah to southern California. This also is called galleta
grass. All the species of Hilaria are important range grasses. The
last three species, with scaly rhizomes instead of stolons and with
glumes bearing an awn on one side, compose Pleuraphis, held by
some as a genus distinct from Hilaria.
81. AEGOPOGON Humb. and Bonpl.
Spikelets short-pedicellate, in groups of 3, the group short-
pedunculate, spreading, the peduncle disarticulating from the axis
and forming a pointed stipe below the group, this falling entire;
central spikelet shorter pedicellate, fertile, the 2 lateral ones longer
pedicellate and staminate or neuter; glumes membranaceous, notched
at the apex, the midnerve extending into a point or awn ; lemma and
palea thinner than the glumes, extending beyond them, the lemma
3-nerved, the central nerve and sometimes also the lateral ones extend-
ing into awns, the palea 2-awned.
Annual low, lax grasses, with short, narrow, flat blades and loose
racemes of delicate flower clusters. Species three, Arizona to Bolivia,
one within the United States.
Type species : Aegopogon cenchroides Humb. and Bonpl.
Aegopogon Humb. and Bonpl. ; Willd. Sp. PI. 4 : 899. 1806. Only one species
is described.
Hymenothecium Lag., Elench. PI. 7. 1816. In the Elenchus, a list of seeds,
occurs Hymenothecium tenellum Lag. based on Cynosurus tenellus Cav. The
genus was published as new by Lagasca in Genera et Species Plantarum, a
work appearing in the same year as the preceding but supposed to be some-
what later. In this work (p. 4) four species are given, H. unisetum, H.
tenellum, H. trisetum (Cynosurus gracilis Cav.), and H. quinquesetum. Cy-
nosurus tenellus Cav. is accepted as the type.
Schellingia Steud., Flora 33: 231, pi. 1. 1850. -Type, 8. tenera Steud., the
only species described. This is Aegopogon cenchroides.
The only species in the United States is Aegopogon tenellus (Cav.)
Trin. (fig. 100), a Mexican species extending into southern Arizona.
It is a pretty little grass, but is of no economic importance.
170 BULLETIN 7*72, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 99. Galleta grass, Jlilaria jamesii. Plant, X \ ; single spike, X 1 ; two views of
group of spikelets, the lower a dorsal view, the upper a ventral view, X 5 ; staminate
spikelet (below), X 5; fertile spikelet seen from the inside and fertile floret
(above), X 5.
GENERA OF GRASSES OF THE UNITED STATES.
7. CHLORIDEAE, THE GRAMA TRIBE.
82. LEPTOCHLOA Beauv.
171
Spikelets 2 to several flowered, sessile or short-pediceled, approxi-
mate or somewhat distant along one side of a slender rachis, the
rachilla disarticulating above the glumes and between the florets;
glumes unequal or nearly equal, awnless or mucronate, 1-nerved,
FIG. 100. Aegopogon tcnellus. Plant, X I ; group of spikelets, X 5 ; lateral spikelet,
X 10 ; central (long-awned) spikelet, X 10.
usually shorter than the first lemma ; lemmas obtuse or acute, some-
times 2-toothed and mucronate or short-awned from between the
teeth, 3-nerved, the nerves sometimes pubescent.
Annual or perennial grasses, with flat blades and numerous spikes
or racemes scattered along a common axis forming a long or some-
172 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
times short panicle. Species probably 20, in the warmer regions;
10 species in the United States, mostly in the Southern and South-
western States.
Type species: Cynosnrus virgatus L.
Leptochloa Beauv., Ess. Agrost. 71, 166, pi. 15, f. 1. 1812. Beauvois includes
three species, Cynosnrus capiltoceus, Eleusine flliformis, and E. virgata, all of
which appear in the index under Leptochloa. The third species is figured and
hence is selected as the type.
Diplachne Beauv., Ess. Agrost. 80, pi. 16, f. 9. 1812. The type is Festuca
fascicularis Lam., the only species mentioned. This is figured by Beauvois.
Rabdochloa Beauv., Ess. Agrost. 84, pi. 17, f. 3. 1812. Beauvois includes
Cynosurus monostachyos, C. I'irgatus, C. domingensis, C. cruciatus, and C.
mucronatus, the last two with question. The species figured, C. domingensis,
in the explanation to the plates called Rabdochloa domingensis, is selected as
the type.
Oxydenia Nutt., Gen, PI. 1: 76. 1818. Only one species included, O. at-
tenuata, which is Leptochloa filiformis.
Some authors * recognize Diplachne as a distinct genus, including Leptochloa
fascicularis, L. floribunda, and L. dubia. In this group the spikelets are some-
what pediceled and are less distinctly arranged in one-sided spikes. Those
who recognize the genus place it in the tribe Festuceae.
Leptochloa filiformis (Lam.) Beauv. (fig. 101) is an annual with
papillate-pilose sheaths, small spikelets, the awnless florets shorter
than the glumes, and numerous very slender spikes 3 to 6 inches long
arranged in a panicle as much as a foot long. This is a weed in
cultivated soil from Virginia to Florida and California; common
also in the Tropics; sometimes called red sprangle-top.
Leptochloa fascicularis (Lam.) Gray is a smooth, erect or pros-
trate annual with several-flowered spikelets, the awned florets longer
than the glumes; found in ditches and brackish meadows from
Massachusetts to Florida and New Mexico.
The other species are more local. Two perennials, L. domingensis
(Jacq.) Trin. and L. virgata (L.) Beauv., are tropical species which
reach the United States in southern Florida and southern Texas,
respectively. Leptochloa dubia (H. B. K.) Nees, a perennial with
comparatively few spikes and broad lemmas notched at the apex, the
nerves glabrous (the margin pubescent), is found in Florida and
from Texas to New Mexico. In the Southwest it is called sprangle
or sprangle-top and Texas crowfoot, and it is important as a forage
grass.
For a revision of the species of Leptochloa found in the United
States, see Hitchcock, U. S. Dept. Agr., Bur. PL Ind. Bull. 33. 1903.
S3. TRIPOGOX Roth.
Spikelets several-flowered, nearly sessile, and appressed in two rows
along one side of a slender rachis, the rachilla disarticulating above
the glumes and bet\veen the florets; glumes somewhat unequal,
acute or acuminate, narrow, 1 -nerved; lemmas narrow. 3-nerved,
1 Nash in Small, Fl. Southeast. U. S. 145, 1900 ; in Britt. and Brown, Illustr. FL, ed. 2,
1:236. 1913.
GENERA OF GRASSES OF THE UNITED STATES 173
FIG. 101. Red sprangle-top, Leptochloa filiformis. Plant, X i ; spikelet and floret, X 10.
174 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
bearing at the base a tuft of long hairs, bifid at the apex, the mid-
nerve extending as a short awn.
Our species is a low, tufted perennial, with capillary blades and
slender solitary spikes, the spikelets somewhat distant. Species about
nine, East Indian and African except one American.
Type species: Tripogon bromoifles Roth.
Tripogon Roth; Roem. and Schult, Syst. Veg. 2:
600. 1817. Only one species described.
The American species, Tripogon spica-
tus (Xees) Ekman (Leptochloa spicata
Scribn.) (fig. 102), is found on sterile hills
in Texas and northern Mexico, Cuba,
and South America. It is of no im-
portance agriculturally.
84. ELEUSINE Gaertn.
Spikelets few to several flowered,
compressed, sessile and closely im-
bricate, in two rows along one side
of a rather broad rachis, the latter
not prolonged beyond the spikelets;
rachilla disarticulating above the
FIG. 102. Tripogon spicatus. Plant, x i ; spikelet and floret, X 5.
glumes and between the florets, glumes unequal, rather broad, acute 3
1-nerved, shorter than the first lemma ; lemmas acute, with 3 strong
green nerves close together forming a keel, the uppermost somewhat
reduced ; seed dark brown, roughened by fine ridges, loosely inclosed
in the thin pericarp.
Annual grasses, with two to several rather stout spikes, digitate
at the summit of the culms, sometimes with one or two a short dis-
GENERA OF GRASSES OF THE UNITED STATES. 175
tance below, or rarely with a single terminal spike. Species about
six, in the warm regions of the Eastern Hemisphere, one a common
introduced weed in America.
Type species: EJeusine coracana Gnertn.
Eieusine Gaertn., Fruct. and Sem. 1 : 7, pi. 1, f. 11. 1788. Two species are
described, E. coracana and E. indica. The first, being figured, is selected as the
type.
Eleusine indica (L.) Gaertn. (fig. 103) is a common garden and
roadside weed throughout the warmer parts of America, extending
northward to Illinois and Massachusetts. It is usually spreading or
prostrate, with two to several spikes, or rarely one. This species is
sometimes called goose-grass and yard-grass.
The type species of the genus, Eieusine coracana Gaertn., is culti-
vated in the Tropics of the Old World for the seed, which is used for
human food by the poor or primitive people. It differs from
E. indica in its larger size, stouter, often incurved spikes, and globose
seed.
85. DACTYLOCTENITJM Willcl.
Spikelets 3 to 5 flowered, compressed, sessile and closely imbricate,
in two rows along one side of the rather narrow flat rachis, the end
projecting in a point beyond the spikelets; rachilla disarticulating
above the first glume and between the florets; glumes somewhat un-
equal, broad, 1-nerved, the first persistent upon the rachis, the second
mucronate or short-awned below the tip, deciduous; lemmas firm,
broad, keeled, acuminate or short-awned, 3-nerved, the lateral nerves
indistinct, the upper floret reduced; the palea about as long as the
lemma ; seed subglobose, ridged or wrinkled, inclosed in a thin, early-
disappearing pericarp.
Annual or perennial grasses, with flat blades and two to several
short thick spikes, digitate and widely spreading at the summit of
the culms. Species three, in the warmer parts of the Eastern Hemi-
sphere, one a common weed in tropical America.
Type species: Cynosurus aegyptius L.
Dactyloctenium Willd., Enum. PI. 1029. 1809. Willdenow describes but one
species, D. aegyptiacum, based on Cynosurm aegyptius L.
Our only species is Dactyloctenium aegyptium (L.) Richt.
(D. aegyptiacum Willd.) (fig. 104), a tropical weed which extends
northward to New York and Illinois. It is a prostrate annual with
2 to 5 spikes, often forming mats rooting at the nodes. Sometimes
called crowfoot grass.
86. CAPRIOLA Adans.
(Cynodon Rich.)
Spikelets 1 -flowered, awnless, sessile in two rows along one side of
a slender continuous rachis, the rachilla disarticulating above the
glumes and prolonged behind the palea as a slender naked bristle,
176 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE,
Tic. 103. Goose-grass, Eleusine indica. Plant, X i ; spikelet, floret, and seed (without
pericarp), X 5.
GENERA OF GRASSES OF THE UNITED STATES.
177
this sometimes bearing a rudimentary lemma ; glumes narrow, acumi-
nate, 1-nerved, about equal, shorter than the floret; lemma strongly
FIG. 104. Crowfoot grass, Dactyloctenium aegyptium. Plant, X i ; spikelet, floret,
and seed (without pericarp), X 5.
compressed, pubescent on the keel, firm in texture, 3-nerved, the
lateral nerves close to the margins.
97769 19 Bull. 772 12
178 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Perennial, usually low grasses, with creeping stolons or rhizomes,
short blades, and several slender spikes digitate at the summit of
the upright flowering stems. Species six, of which three are Aus-
tralian, one species widely dis-
tributed in the warmer regions
of the globe.
Type species: Panicum dacty-
lon L.
Capriola Adans., Fam. PI. 2: 31,
532. 1763. The genera are indi-
cated and distinguished by Aclanson
in a much abbreviated and often un-
satisfactory manner. The tabular
arrangement of the genera of Phal-
arides, his first section of the grass
family or Gramina, includes Cap-
FIG. 105. Bermuda grass, Capriola dactylon. Plant,
floret, X 5.
X 2 ; spikelet and two views of
riola, with the following diagnosis, interpreting the table : Summit of leaf sheath
hairy ; flowers in digitate spikes ; glumes laterally compressed ; lemma awn less.
In the index there is given as a synonym under Capriola, " Gramen dactylon
Offic." The last phrase appears in the first edition of the Species Plantarum 1
in the synonymy under Panicum dactylon as " Gramen dactylon, radice repente.
s. officinarum. Scheuch. gram. 104," thus connecting Capriola Adans. with
Panicum dactylon.
Cynodon Rich. ; Pers., Syn. PI. 1: 85. 1805. Only one species described, C. dac-
tylon, based on Panicum dactylon L.
The only species in Xofth America is Capriola dactylon (L.)
Kuntze (fig. 105), commonly known as Bermuda grass. This is a
., Sp. PL 58. 1753.
GENERA OF GRASSES OF THE UNITED STATES. 179
native of the Mediterranean region, but is common in the southern
United States, extending north to Maryland, southern Kansas, and
the interior valleys of California.
Bermuda grass is the most important pasture grass of the South-
ern States, and is also widely utilized there as a lawn grass. On
alluvial ground it may grow sufficiently rank to be cut for hay. It
propagates readily by its rhizomes and stolons and on this account
may become a pestiferous weed in cultivated fields. This grass is
known also as wire-grass (especially the weedy form in fields), Ba-
hama grass in the West Indies, and manienie in the Hawaiian
Islands.
A. larger form, Capriola dactylon maritima (H. B. K.) Hitchc.
(Cynodon maritimus H. B. K.), is found along the seacoast of
Florida.
87. WILI/KOMMIA Hack.
Spikelets 1-flowered, dorsally compressed, sessile in two rows on
one side of a slender rachis and appressed to it, the rachilla some-
what lengthened below and above the second glume, disarticulating
just above it, not prolonged above the floret; glumes thin, the first
narrow, about two-thirds as long as the second, nerveless, obtuse,
the second 1-nerved, subacute; lemma about as long as the second
glume, awnless, 3-nerved, the lateral nerves near the margin, the
back of the lemma sparingly pubescent between the nerves, the mar-
gins densely covered with silky hairs; palea 2-nerved, the nerves
densely silky hairy.
Annuals or perennials, with several short spikes scattered along a
main axis; our species, a low, tufted perennial. Species four; three
in South Africa, one in Texas.
Type species: Willkommia sarmcntosa Hack.
Willkommia Hack., Verh. Bot. Ver. Brandenburg 30: 145. 1888. Hackel de-
scribes two species, W. sarmentosa, a perennial, and W. annua, ,an annual, both
from German Southwest Africa. The first species is selected as the type.
Willkommia texana Hitchc. (fig. 106), confined to a few localities
in Texas, in alkali spots in prairies and openings in woods, has no
agricultural importance.
88. SCHEDONNARDUS StCUd.
Spikelets 1-flowered, sessile and somewhat distant in two rows on
one side of a slender, continuous 3-angled rachis, appressed to its
slightly concave sides, the rachilla disarticulating above the glumes,
not prolonged; glumes narrow, stiff, somewhat unequal, acuminate,
1-nerved ; lemmas narrow, acuminate, a little longer than the glumes,
3-nerved.
A low, tufted perennial, with stiff, slender, divergent spikes ar-
ranged rather remotely along a common axis. Species one, on the
Great Plains of the United States and in Argentina.
180 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Type species : Schedonnardus texanus Steud.
Schedonnardus Steud., Syn. PI. Glum. 1:146. 1854. A single species de-
scribed, S. texanus, based on Drumiuond's no. 360 from Texas. This is /S.
paniculatus (Nutt.) Trel. (Lcp-
turns paniculatus Nutt.).
Spirochloe Lunell, Amer.
Midi. Nat. 4: 220. 1915. Pro-
posed for " Schedonnardus
Steud ... not thought per-
missible, being built on
Nardus."
Schedonnardus panicu-
latus (fig. 10T), the only
species of the genus, is
found on prairies and
plains from Montana and
Illinois to Texas. The axis
of the inflorescence elon-
gates after flowering, be-
coming 1 to 2 feet long,
curved in a loose spiral.
The whole breaks away at
maturity and rolls before
the wind as a tumbleweed.
The species is a forage
grass, but the plants are
low and in the main form
only an inconsiderable pro-
portion of the total forage.
89. BECKMANNIA Host.
Spikelets 1-flowered,
rarely 2-flowered, laterally
compressed, subcircular,
nearly sessile and closely
imbricate, in two rows
along one side of a slender
continuous rachis, disartic-
ulating below the glumes,
FIG. 106. Willkommia texana.
Plant, X I ; two views of spikelet and two views of
floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 181
falling entire; glumes equal, inflated, obovate. 3-nerved, rounded
above but the apex apiculate; lemma narrow, 5-nerved, acuminate,
about as long as the
glumes; palea 2-
nerved, nearly as
long as the lemma.
Aa erect, rather
stout annual, with
flat blades and nu-
merous short ap-
pressed spikes in a
narrow more or less
interrupted panicle.
Species one, in the
cooler parts of
America and Eur-
asia.
Type species : PJialaris erucae-
fonnis L.
Beckmannia Host, Gram.
Austr. 3: 5, pi. 6. 1805. Only
one species described.
Beckmannia erueaeformis
(L.) Host (fig. 108) is a
marsh plant, found from
Iowa to California and
Alaska where it is often
called slough-grass. It is
FIG. 107. Schedonnardus t> aniculatus. palatable to Stock, is
Plant, X I ; spikelet and floret, X 5. r
182 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
times sufficiently abundant locally to be an important forage
grass, and is not infrequently used for hay. The European
form has 2-flowered
spikelets.
90. SPARTINA Schreb.
Spikelets 1-flow-
ered, much flattened
laterally, sessile and
usually closely im-
bricate, on one side
of a continuous ra-
chis, disarticulating
below the glumes,
the rachilla not pro-
duced beyond the
floret; glumes
keeled, l-nerved 5
FIG. 108. Slough-grass, Beckmannia erucaeformis.
X 5.
Plant, X
spikelet and floret,
GENERA OF GRASSES OF THE UNITED STATES. 183
acute or short-awned, the first shorter, the second often ex-
ceeding the lemma; lemma firm, keeled, the lateral nerves obscure,
narrowed to a rather obtuse point; palea 2-nerved, keeled and flat-
tened, the keel between or at one side of the nerves.
Stout, erect, often tall perennials, with usually extensively creep-
ing, firm, scaly rhizomes, long tough blades, and two to many ap-
pressed or sometimes spreading spikes racemose on the main axis.
Species about 14, all North American except two or three along the
coast of Europe, Africa, and South America.
Type species: Spartina schreberi Gmel,
Spartina Schreb. ; Ginel., S-yst. Nat. ed. 13. 2 : 123. 1791. The genus was first
described by Schreber in his Genera Plantarum, 1 but no species was mentioned.
Ginelin merely assigns a specific name to the description given by Schreber.
Spartina schreberi is not recognized by European botanists, but it doubt-
less is the common European species, S. maritima (Curt.) Fernald (S. stricta
Roth).
Trachynotia Michx., Fl. Bor. Amer. 1: 63. 1803. Type species T. cyno-
suroides. Michaux describes three species, T. cynosuroides, T. polystachya, and
T. juncea. The first species described is what is now called Spartina michauxi-
ana Hitchc., but the synonym, Dactylis cynosuroides L., from which the specific
name is taken, shows that Michaux had misapplied the name. The second spe-
cies, T. polystachya, is Dactylis cynosuroides L., now called Spartina cynosu-
roides (L.) Roth. Michaux remarks that this may be only a variety of the first
species. It appears then that to Michaux the first species typifies the genus,
and hence is selected here as the type species.
Limnetis Pers., Syn. PI. 1 : 72. 1805. Four species are described, L. pungens,
L. juncea, L. cynosuroides, and L. polystachya. The first species, which is the
same as Spartina maritima, is selected as the type, as that is a native of Europe
and is indigenous from the standpoint of the author. The other three species
are American.
There are eight species in the United States. All but two are found
on or near the coast. Spartina cynosuroides (L.) Roth, a stout grass
as much as 9 feet tall, is found along the Atlantic coast. The com-
monest coastal species is S. patens (Ait.) Muhl. (including S. juncea
Michx.) , which covers vast areas of salt marsh from Newfoundland to
Texas. This is a slender wiry species usually less than 3 feet tall, with
only a few somewhat spreading spikes. Spartina alterniftora Loisel.
and its two varieties, glabra (Muhl.) Fern, and pilosa (Merr.) Fern.,
also of the Atlantic coast, have stout stems and closely appressed
spikes, forming a cylindric inflorescence. A somewhat local species,
S. sp.irtinae (Trin.) Merr., is found on the Texas coast. Another
local species, S. foliosa Trin., is found on the coast of California. The
only species without well-marked rhizomes is S. ~ba~keri Merr., of the
f resh- water marshes and low savannas of Florida and coastal Georgia.
Two species are found in the interior of the United States. One, &.
michauxiana Hitchc. (fig. 109), is common in marshes and sloughs
from New England to the Great Plains. A second, S. gradlis Trin., is
found in alkaline grassland in the Western States. The first of these
is used for thatching sheds and covering hay stacks. The leaves of
1 Schreb. Gen. PI. 1: 43. 1789.
184 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE,
FIG. 109.- Marsh-grass, Spartina michauxiana. Plant, X \ ; spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 185
S. bakeri and S. patens jimcea (Michx.) Hitchc. are used for making
brooms. The marsh hay of the Atlantic coast, much used for bedding
and packing, often consists largely of JS. patens. The species of
Spartina are too coarse for forage.
For a revision of the species found in the United States, see Mer-
rill, U. S. Dept. Agr., Bur. PL Ind. Bull. 9. 1912.
91. CAMPULOSUS Desv.
(Ctenium Panzer.)
Spikelets several-flowered but with only one perfect floret, sessile
and closely imbricate, on one side of a continuous rachis, the rachilla
disarticulating above the glumes; glumes unequal, the first small,
hyaline, 1-nerved, the second as long as the lemmas, firm, 3 to 4
nerved, bearing on the back a strong divergent awn ; lemmas rather
papery, 3-nerved, villous on the lateral nerves and on the callus,
bearing a short straight awn on the back just below the apex, the first
and second lemmas empty, the third inclosing a perfect flower, the
upper 1 to 3 empty and successively smaller.
Erect, slender, rather tall perennials, with usually solitary, often
curved spikes. Species about 12, in the warm regions, three being
in the Eastern Hemisphere and the rest in America ; two species are
found in the southeastern United States.
Type species: Chloris monostachya Michx.
Campulosus Desv., Nouv. Bull. Soc. Philom. Paris 2 : 189. 1810. Two species
are mentioned, C. gracilior Desv. (based on Chloris monostachya Michx., which
is Campulosus aroma ticus ), and C. hirsulus Desv. (based on Chloris falcata
Swartz). The first is selected as the type. The second is now referred to
Harpechloa.
Ctenium Panzer, Denkschr. Baier. Akad. Wiss. Miinchen 4 : 288, pi. 13. 1813.
(Ideeli Gatt. Graser, 38.) Only one species is described, Chloris monostachya
Michx., to which Panzer gives the name Ctenium carolinianum.
Monocera Ell., Bot. S. C. and Ga. 1: 176. 1816. A single species, based on
Aeoilops aromaticum Walt., is included.
Monathera Raf., Amer. Month. Mag. 4: 190. 1819. "Monocera Elliott . . .
must be changed, because there is already a genus of shell of the same name."
Our two species are confined to the Southeastern States, one of
them, Campulosus floridanm Hitchc., to Florida, the other, C. aro-
maticus (Walt.) Trin. (fig. 110), called toothache grass, extending
from North Carolina along the Coastal Plain to Louisiana. Both
species are rather infrequent and neither is of importance agri-
culturally.
92. GYMNOPOGON Beauv.
Spikelets 1 or rarely 2 or 3 flowered, nearly sessile, appressed and
usually remote in two rows along one side of a slender continuous
rachis, the rachilla disarticulating above the glumes and prolonged
behind the one or more fertile florets as a slender stipe, bearing a
rudiment of a floret, this sometimes with one or two slender awns ;
186 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
glumes narrow, acuminate, 1 -nerved, usually longer than the floret;
lemmas narrow, 3-nerved, the lateral nerves near the margin, the
FIG. 110. Toothache grass, Campulosus aromaticus. Plant, X \ ', splkelet and fertile
floret (palea side up), X 5.
apex minutely bifid, bearing between the teeth a slender awn, or
rarely awnless.
GENERA OF GRASSES OF THE UNITED STATES. 187
Perennial or rarely annual grasses, with short, flat, stiff blades,
numerous stiff, slender, divergent spikes loosely scattered along the
upper part of the culm, or sometimes aggregate toward the summit,
the spikes often deflexed at maturity. Species 10, nearly all Amer-
ican ; 3 species in the southeastern United States.
Type species : Andropogon ambiguus Michx.
Gymnopogon Beauv., Ess. Agrost. 41, pi. 9, f. 3. 1812. Beauvois mentions one
species, Andropogon ambiguus Michx., which is figured. In the description of
the plate the name given is Gymnopogon, raceinosus.
Alloiatheros Ell., Bot. S. C. and Ga. 1: 146. 1816. This name is casually
mentioned by Elliott in the description of Andropogon ambiguus: "I once in-
tended to insert it as a distinct genus under the name of Alloiatheros, from the
dissimilarity of its awns, not only in position but in figure."
Anthopogon Nutt, Gen. PI. 1: 81. 1818. Based on Andropogon ambiguus
Michx., which name Nuttall changes to Anthopogon lepturoides.
The spikelets are usually 1-flowered and awned,but in G-ymnopogon
chapmanianus Hitchc., of Florida, they are 2 to 4 flowered and awn-
less. This species shows in its spikelet characters a transition to
Leptochloa, but in habit it closely resembles the other two species of
the United States. In G. foliosm (Willd.) Nees, of Porto Eico and
South America, the rudiment bears two long awns. Our species are
perennials, with an inflorescence of scattered spikes.
Our commonest species is Gymnopogon ambiguus (Michx.) B. S. P.
(fig. Ill) , found in sandy soil from New Jersey to Missouri and south
to Florida and Texas. Another species, G. l>revifolius Trin., grows
from New Jersey to Florida. This species differs from the preced-
ing in having the rachis spikelet bearing only along the upper half .
The species have no agricultural importance.
93. CHLOBIS Swartz.
Spikelets with 1 perfect floret, sessile, in two rows along one
side of a continuous rachis, the rachilla disarticulating above the
glumes, produced beyond the perfect floret and bearing 1 to several
reduced florets consisting of empty lemmas, these often truncate, and,
if more than one, the smaller ones inclosed in the lower, forming a
usually club-shaped rudiment; glumes somewhat unequal, the first
shorter, narrow, acute; lemma keeled, usually broad, 1 to 5 nerved,
often villous on the callus and villous or long-ciliate on the keel or
marginal nerves, awned from between the short teeth of a bifid apex,
the awn slender or sometimes reduced to a mucro, the sterile lemmas
awned or awnless.
Perennial or sometimes annual, tufted grasses, with flat blades and
two to several often showy and feathery spikes aggregate at the
summit of the culms. Species about 60, in the warmer regions ; 15 in
the southern United States.
Type species : Agrostis cruciata L.
Chloris Swartz, Prod. Veg. Ind. Occ. 25. 1788. Swartz describes five species,
C, cruciata, C. ciliata, C. petraea, C. polydactyla, and C. radiata, all from the
188 BULLETIN 772, U. S. DEPARTMENT OP AGRICULTURE.
FIG. 111.- Gymnopogon ambigitus. Plant, X \ ', spikelet and floret, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 189
West Indies. The second and third are described as new ; the others are based
on Linnsean species, the first on Agrostis cruciata, the fourth "on Andropogon
polydactylon, and the fifth on Agrostis radiata. The first species is selected as
the type.
Eustachys Desv., Nouv. Bull. Soc. Philom. Paris 2: 188. 1810. One species
is described, E. petraeus, based oil Chloris petraea Swartz. Eustachys, recog-
nized by some American botanists as distinct, forms a section of the genus
Chloris and includes four species, C. petraea, C. glauca (Chapm.) Vasey, C.
floridana (Chapm.) Vasey, and C. neglecta Nash. The group differs from
Euchloris in having the lemmas short-awned or mucronate, brown, and rather
firm in texture.
Chlorostis Raf., Princip. Fondament. Somiologie 26, 29. 1814. Proposed
change of name for Chloris Swartz, because of Chlora L. ( : an animal) .
Several species are found on the plains of Texas, where they form
an unimportant part of the forage for grazing animals. Chloris
verticittata Nutt. and its allies are known as windmill grasses. The
mature inflorescence, consisting of several slender, divergent spikes,
breaks away from the plant and rolls before the wind as a tumble-
weed. In the Southwestern States is found C. virgata Swartz (C.
elegans H. B. K.) (fig. 112), a tuftecl annual, 1 to 2 feet high, with
several pale or purplish, erect, feathery spikes 1 to 2 inches long. This
species invades cultivated fields and sometimes becomes a rather
common weed, especially in alfalfa fields.
One species, C. gayana Kunth, a native of South Africa, is culti-
vated to a limited extent as a forage grass. This species, called
Rhodes grass, has been shown to have value as a meadow grass in
the Southwestern States. In the Hawaiian Islands it is used on some
of the ranches in the drier regions. Rhodes grass is a perennial, 2
to 3 feet high, producing long, stout, creeping, propagating stems or
stolons and bearing at the summit of the flowering stems a close fan-
shaped cluster of numerous spikes 2 to 4 inches long.
For a revision of the species of Eustachys and Chloris found in the
United States, see Nash, Bull. Torrey Club 25 : 432-450. 1898.
94. TRICHLORIS Fourn.
Spikelets 1 to few flowered, nearly sessile, in two rows along one
side of a continuous slender rachis, the rachilla disarticulating above
the glumes and prolonged behind the uppermost perfect floret, bear-
ing a reduced, usually awned floret; glumes unequal, acuminate, or
short-awned, the body shorter than the lower lemma; lemmas nar-
row, 3-nerved, the marginal nerves sometimes pubescent, these and
the midnerve extending into awns, the central long and slender, the
lateral often much shorter.
Erect, slender, tufted perennials, with flat blades and numerous
erect or ascending spikes, aggregate but scarcely digitate at the
summit of the culms. Species two or three, in the dry regions of
Texas and Mexico and also in Argentina.
190
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Type species : Trichloris pluriflora Fourn.
Trichloris Fourn., Mex. PI. 2: 142. 1886. Fournier includes two specie:
T. fasciculata and T. pluriflora, both described as new. In the generic descrij
FIG. 112. Chloris viryata. Plant X \ ; glumes and floret with rudiment, X i
tion occurs the statement " flore summo tabescente mutico." Under the secon
species one finds " flore summo mutico." From this it would appear tha
T. pluriflora represented Fournier's idea of the genus; hence this species i
selected as the type.
GENERA OF GRASSES OF THE UNITED STATES. 191
Chloropsis Hack. ; Kuntze, Rev. Gen. PI. 2 : 771. 1891. The name was men-
tioned by Hackel 1 as a synonym under Trichloris. Hackel also mentions
Chloridopsis, both names having been used by gardeners for Trichloris blan-
chardiana Hack, of Argentina. Kuntze changes the name Trichloris to Chlor
opsis, because of the earlier Trichlora Baker. Both Trichlora and Trichloris
may be considered valid, since they have different derivations and slightly
different spellings. Since Kuntze adopts Hackel's name and since Hackel
mentions Chloropsis blanchardiana, this species is selected as the type of
Chloropsis.
The two species of the United States, Trichloris mendocina (Phil.)
Kurtz (T. fascieulata Fourn.) (fig. 113) and T. plwriflora Fourn.,
are found in the arid regions of northern Mexico and extend into
western Texas, southern New Mexico, and southern Arizona. The
first has spikelets with one perfect floret and a rudiment, each with
three long awns; the second has spikelets with 3 to 5 florets, the
upper one or two reduced, the lateral awns reduced or sometimes
wanting. Neither is of importance agriculturally.
95. BOTJTELOUA Lag., the grama grasses.
Spikelets 1 -flowered, with the rudiments of one or more florets
above, sessile, in two rows along one side of the rachis; glumes un-
equal, 1-nerved, acuminate or awn-tipped, the first shorter and nar-
rower; lemma as long as the second glume or a little longer, 3-nerved,
the nerves extending into short or often rather long awns, the in-
ternerves usually extending into teeth; palea 2-nerved, sometimes
2-awned; rudiment various, usually 3-awned, a second rudimentary
floret sometimes present.
Perennial or sometimes annual, low or rather tall grasses, with two
to several or many spikes racemose on a common axis, or sometimes
solitary, the spikelets few to many in each spike, rarely solitary,
pectinate or more loosely arranged and appressed, the rachis of the
spike usually produced beyond the insertion of the spikelets. Spe-
cies 38, all American and chiefly North American; 18 species found
in the United States, mostly in open grassland of the southwestern
States.
Type species : Bouteloita racemosa Lag.
liouteloua Lag., Varied. Cienc. Lit. and Art. 2 4 : 134. 1805. Lagasca gives
five species, B. racemosa, B. hirsuta, B. barbata, B. simplex, and B. prostrata.
All ;;re briefly described, except the last, which is mentioned by name only. The
first species (which is the same as B. curtipendula) is selected as the type. In
this work Lagasca spells the name of the genus " Botelua " and states that he
names the genus in honor of the two brothers Boutelou. In a later work 2
Lagasca describes the genus under the name Bouteloua, and includes 10 species,
the first of which is B. htysuta. The spelling Bouteloua is retained because it
was corrected to this form by the author to correspond to the spelling of the
personal name of the brothers Boutelou, and because this second spelling has
been universally accepted by botanists.
Atheropogon Muhl. ; Willd., Sp. PI. 4: 937. 1806. A single species is described,
A. apludioides Muhl., which is Bouteloua curtipendula.
Triathera Desv., Nouv. Bull. Soc. Philom. Paris 2: 188. 1810. Based on
Aristida amtrwana L., which is Bouteloua americana (L.) Scribn., a West
Indian species.
*In Engl. and Prantl, Pflanzeafam. 2 2 : 59. 1887. 2 Gen. and Sp. Nov. 5. 1816.
192 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 113. Trichloris inendoctna. Plant, X J ; glumes and floret with rudiment, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 193
Heterosteca Desv., Nouv. Bull. Soc. Philom. Paris 2: 188. 1810. Based on
//. juncifolia, which is Bouteloua heterostega (Trin.) Griffiths, of the West
Indies.
Chondrosium Desv., Nouv. Bull. Soc. Philom. Paris 2 : 188. 1810. Based on
Chloris procumbens Durand (Bouteloua procumbens).
Polyodon H. B. K., Nov. Gen. and Sp. 1 : 174, pi. 55. 1816. Based on a single
species, P. distichum H. B. K.
Triaena H. B. K., Nov. Gen. and Sp. 1 : 178. 1816. A single species described,
T. racem<osa, which is Bouteloua triaena (Trin.) Scribn.
Eutriana Trin., Fund. Agrost. 161. 1820. Trinius includes two species, E.
curtipendula and E. bromoides. The first is selected as the type.
The species fall into two rather well marked divisions, those in
which the spikelets are crowded and pectinate and the spikes persist-
ent on the main axis, the florets falling, and those in which the
spikelets are less crowded, ascending rather than pectinate on the
rachis, and the spikes falling entire. Bouteloua gracilis and its
allies are examples of the first group and B. filiformis (Fourn.)
Griffiths and its allies, B. curtipendula and B. aristidoides of the sec-
ond. The genus is important, since many of the species are the
chief ingredient of the grazing lands of the Southwestern States.
Bouteloua gracilis Lag. (B. oligostachya Torr.) (fig. 114) is
found on the Great Plains from Manitoba to Mexico and even south-
ward to South America. It is the blue grama of the ranchmen and,
along with buffalo grass (Bulbilis dactyloides} and curly mesquite
(Hilaria belangeri) , constitutes most of what is known in the Middle
West as "short-grass." Blue grama is a tufted perennial, with
numerous short leaves and a flower stalk about a foot high with 2
or 3 spikes about an inch long. These spikes, one at the end of the
stem and the other one or two a short distance below, turn with the
wind like weather vanes. An allied species, B. Mrsuta Lag.,
called black grama, is found over about the same region, but is con-
fined chiefly to rocky hills. This species differs in having shorter,
niore fuzzy spikes and in the prolonged end of the rachis, which
forms a distinct point beyond the spikelets.
Another widely distributed species is Bouteloua curtipendula
(Michx.) Torr. (B. racemosa Lag.) (fig. 115), called side-oats
grama. It extends farther east than the other species, being found
even as far as Connecticut. Side-oats grama is the tallest of the
species, sometimes as much as 3 feet, and is further distinguished
by the numerous (35 to 50) short, reflexed spikes.
In Arizona and New Mexico other species become prominent.
Bouteloua eriopoda Torr., called here black grama and woolly-foot,
is a low creeping species with woolly stem. Bouteloua rothrockii
Vasey is the most important range grass in many parts of Arizona.
It grows about a foot high and has five or six spikes to each culm.
In B. texana S. Wats., of the Texas plains, the short triangular
spikes fall from the axis entire.
97769 19 Bull. 772 13
194 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Three species are annuals, B. aristidoides Thurb., B. procumbens
(Durand) Griffiths (B. prostrata Lag.), and B. barbvta Lag. (B.
polystachya Torr.). These are found from Texas to Arizona, where
they are called six-weeks grama. They furnish forage when young,
but are of secondary importance.
For a revision of the spe-
cies of Bouteloua and its
allies, see Griffiths, Contr.
U. S. Nat. Herb. 14:343-
424. 1912. Economic notes
and synonymy are included.
96. CATHESTECUM Presl.
Spikes consisting of 3
spikelets, the upper or cen-
tral perfect, the 2 lateral
stammate or rudimentary,
the spike falling entire;
central spikelet with one
perfect floret below and one
or more reduced florets
above; glumes unequal, the
first a short, thin, nerveless
scale in the central spikelet,
narrow and acuminate in
the lateral spikelets, the
second about as long as the
lemma, acuminate, all usu-"
FIG. 114. Blue grama, Bouteloua gracilis. Plant, X 2
glumes, floret with rudiment, and floret alone, X 5.
ally villous; lemma 3-nerved, or rarely 5 to 7 nerved, the nerves
extending into awns, and the internerves into teeth ; palea 2-nerved,
the nerves extending into short awns; second and third floret with
GENERA OF GRASSES OF THE UNITED STATES.
195
a fairly well developed lemma and palea, the fourth floret, if
present, usually reduced.
Low cespitose or stoloniferous
annuals or perennials, with short
blades, and several or many short
deciduous spikes scattered along
the main axis. Species four, on the
Mexican Plateau, one extending
into western Texas.
FIG. 115. Side-oats grama, Bouteloua curtipendula. Plant, X \ ; spikelet and floret
with rudiment, X 5.
Type species: Cathestccum prostratum Presl.
Cathestecum Presl, Rel. Haenk, 1; 294, pi. 42. 1830. Only one species de-
scribed.
196 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
The only species found in the United States is Cathestecwn erec-
tum Vasey and Hack. (fig. 116), a stoloniferous perennial with the
aspect of Bouteloua texcma but more delicate. This species is known
in western Texas from a very few collections, but is more common
FIG. HG.Cathestecum erectum. Plant, X I ; group of spikelets (reduced spike), central
spikelet, and fertile floret, X 5.
in northern Mexico. Cathestecum is placed by Bentham 1 doubt-
fully in the tribe Zoysieae, and by Hackel 2 in the tribe Festuceae.
Griffiths 3 shows its affinity to Bouteloua and places it in the tribe
Chlorideae.
1 Benti-. and Hook. Gen. PI. 3: 1122. 1883.
2 Engl. and Prantl, Pflanzenfam. 2 2 : 65. 1887.
3 Contr. U. S. Nat, Herb. 14: 358. 1912,
GENERA OF GRASSES OF THE UNITED STATES. 197
97. MUNROA Torr.
Spikelets in pairs or threes on a short rachis, the lower one or two
larger, 3 or 4 flowered, the upper 2 or 3 flowered, the group (reduced
spikes) inclosed in the broad sheaths of short leaves, usually about
3 in a fascicle, forming a cluster or head at the ends of the
branches; rachilla disarticulating above the glumes and between the
florets ; glumes of the lower 1 or 2 spikelets equal, 1-nerved, narrow,
acute, a little shorter than the lemmas, those of the upper spikelet
unequal, the first much shorter or obsolete; lemmas 3-lierved, those
of the lower spikelet coriaceous, acuminate, the points spreading, the
midnerve extended into a mucro, those of the upper spikelet mem-
branaceous ; palea narrow, 2-nerved, inclosing the oval, dorsally com-
pressed caryopsis.
Low spreading, much-branched annuals, the short, flat, pungent
leaves in fascicles. Species three, plains of America ; two in Argen-
tina, one in the western United States.
Type species : Crypsis squarrosa Nutt.
Munroa Torr., U. S. Rep. Expl. Miss. Pac. 4: 158. 1856. One species de-
scribed, M. squarrosa (Nutt.) Torr. Torrey spells the genus Monroa, naming it
in honor of Munro, whom he refers to erroneously as Major " Monro."
The prophylla are prominent in the fascicles of leaves, the two
nerves extending into long, green tips. The lower spikelet is bulged
out on the lower side, throwing the glumes forward; thus they
appear somewhat asymmetric. This genus has hitherto been placed
in Festuceae, but the structure of the spikelet and spike show closer
affinity to genera of Chlorideae.
Munroa squarrosa (fig. 117) is common on the Great Plains from
Montana to northern Mexico, usually in new soil and open ground.
It has little or no importance as a forage grass. It is sometimes
abundant on recently broken sod. Munroa mendocina Phil., of
Argentina, has been referred to M. squarrosa, but it is a distinct
species.
98. BULBILIS Eaf.
(BucMoe Engelm.)
Plants unisexual. Staminate spikelets 2-flowered, sessile and
closely imbricate, in two rows on one side of a slender rachis forming
a short spike; glumes somewhat unequal, rather broad, 1-nerved,
acutish; lemmas longer than the glumes, 3-nerved, rather obtuse,
whitish; palea as long as its lemma, 2-nerved. Pistillate spikelets
mostly 3 to 5 in a short spike or head, this falling entire, usually
2 heads to the inflorescence, the common peduncle short and
included in the somewhat inflated sheaths of the upper leaves, the
thickened somewhat woody rachis and the 2 or 3 outer (second)
glumes appearing like an involucre; glumes very unequal, the first
inside relative to the cluster, thin, 1-nerved, keeled, the nerve extend-
198 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
ing into a point or awn, as long as the lemma or reduced in some of
the spikelets or wanting, the second glume firm, thick and woody,
almost surrounding the remainder of the spikelet, rounded on the
back, white or yellowish, obscurely nerved, the margins inflexed, thin,
ciliate, the upper part greenish, acuminate, spreading, with one or
two teeth at the sides; lemma firm-membranaceous, 3-nerved, dor-
sally compressed, broad below, narrowed into a 3-lobed green summit,
the middle lobe much the larger ; palea 2-nerved, broad, obtuse, about
as long as the body of the lemma, enveloping the caryopsis.
Fio. 117. Munroa sguarrosa.
Plant, X \\ group of spikelets (reduced spike),
and floret, X 5.
spikelet,
A low stoloniferous perennial, with short curly blades, the
staminate flowers in two or three short spikes on slender, erect culms,
the pistillate in sessile clusters partly hidden among the leaves.
Species one, on the Great Plains from Montana to Mexico.
Type species : Seslqria dactyloides Nutt.
Bulbilis Raf., Amer. Month. Mag. 4: 190. 1819. Rafinesque gives a review
of Nuttall's Genera of North American Plants. The part relating to Bulbilis is,
" Sesleria dactyloides must form a peculiar genus by Mr. N's own account, it
may be called Bulbilis."
Calanthera Kunth, in Hook. Kew Journ. 8: 18. 1856. A single species in-
cluded, " G. dactyloides Kth. Nutt. Sesleria . . . Buffalo grass."
GENERA OF GRASSES OF THE UNITED STATES. 199
Buchloe Engelm., Trans. Acad. St. Louis 1: 432. 1859. Based on Sesleria
dactyloides. Engelmann gave the first description of the genus. Nuttall's de-
scription of Seslcria dactyloides was based on the staminate plant.
The species is usually described as dioecious * because the staminate and pis-
tillate flowers are found on different individuals. Experiments in growing the
plants from seed show that they are monoecious, the two kinds of flowers aris-
ing from distinct branches which propagate vegetatively, each branch produc-
ing its own kind. 2 Plank 3 observed that seedlings were monoecious.
Bulbilis dactyloides (Nutt.) Raf. (Buchloe dactyloides Engelm.)
(fig. 118), commonly known as buffalo grass, is one of the chief
constituents of the sod on the Great Plains. It forms, when unmixed
with other grasses, a close, soft, grayish green turf. Buffalo grass
is dominant over large areas on the uplands, colloquially known as
the " short-grass country," and is one of the most important grazing
grasses of this region. The- sod houses of the early settlers were
made mostly from the sod of this grass.
8. PHALARIDEAE, THE CANARY-GRASS TRIBE.
99. TORKESIA Ruiz and Pav.
(Hierochloe R. Br., Savastana Schrank.)
Spikelets with one terminal perfect floret and two staminate flo-
rets, disarticulating above the glumes, the staminate florets falling
attached to the fertile one; glumes equal, broad, thin and papery,
smooth, acute; sterile lemmas about as long as the glumes, mostly
somewhat appressed-hispid, sometimes awned from between two
lobes ; fertile lemma somewhat indurate, about as long as the others,
smooth or nearly so, awnless; palea 3-nerved, rounded on the back-.
Perennial, low, erect, sweet-smelling grasses, with small panicles of
bronze-colored spikelets. Species about 17, confined to cool and,
alpine regions ; 3 species in the United States.
Type species : Torresia utriculata Ruiz and Pav.
Savastana Schrank, Baier. Fl. 1: 100, 337, 1789, not Savastania Scop., 1777.
Type, 8. hirta Schrank, the only species described.
Torresia Ruiz and Pav., Syst. Veg. Peruv. Chil. 251. 1798. A single species
described.
Hierochloe R. Br., Prodr. Fl. Nov. Holl. 208. 1810. Type, Disarrenum
antarcticum Labill. upon which is based the only species described (H. antarc-
tica). Later authors have often spelled this Hierochloa.
Dimesia Raf., Amor. Month. Mag. 2 : 175. 1818. Based on " Holcus fra grans
of Pursh's Flora." This is the same as Torresia odorata.
The common species, Torresia odorata (L.) Hitchc. (Hierochloe
odorata Wahl., II. borealis Koem. and Schult.) (fig. 119), called holy
grass, vanilla grass, or Seneca grass, grows in Canada and the north-
ern part of the United States. Like all the species of the genus and
the allied genus Anthoxanthum, it is sweet scented, owing to the
1 Pilger discusses this and other species in a paper on monoecious and dioecious grass
genera. Bot. Jahrb. Engler 84 : 377. 1904.
2 Hitchcock, Bot. Gaz. 20: 464. 1895.- 3 Bull. Torrey Club 19: 303. 1892.
200 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 118. Buffalo grass, Bulbilis dactyloides. Pistillate plant (above), X J; group of
pistillate spikelets (reduced spike), and floret, X 5; staminate plant (below), X J;
staminate spikelet, X 5.
GENERA OF GRASSES OF THE UNITED STATES.
201
presence of coumarin. The Indians use the grass to make fragrant
baskets.
Torresfa alpina (Swartz) Hitchc., with small, condensed panicles
and awned staminate florets, is arctic and extends to the alpine peaks
of New York and New England; T.
macrophylla (Thurb.) Hitchc., with
broad blades, is Californian.
100. ANTHOXANTHUM L,
Spik'elets with 1 terminal perfect
floret and 2 sterile lemmas, the rachilla
disarticulating above the glumes, the
sterile lemmas falling attached to the
fertile floret; glumes unequal, acute
or mucronate; sterile lemmas shorter
than the glumes, empty, awned from
the back; fertile lemma shorter than
the sterile ones, awnless; palea 1-
nerved, rounded on the back, inclosed
in the lemma.
Sweet-smelling annual or perennial
grasses, with flat blades and spikelike
panicles. Species about four,
Europe and Asia; two intro-
duced into the United States.
Type species : Anthoxanthwtn
odoratum L.
Anthoxanthum L., Sp. PI. 28,
1753; Gen. PI., ed. 5, 17. 1754.
Linnaeus describes three species,
A. odoratum, A. indicum, and A.
paniculatum. The first is chosen
as the type. The second species is
now referred to Perotis and the
third to Festuca.
FIG. 119. Vanilla grass, Torresia odorata. Plant, X \ ; spikelet, florets with the glumes
'removed, and fertile floret, X 5.
Anthoxanthum odoratum, sweet vernal grass (PI. XV; fig. 120), is
sometimes included in meadow mixtures to give fragrance to the hay.
202 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
The grass has no forage value. It is now common along roadsides
and in grassland throughout the Eastern States. Like the species of
Torresia it has an aromatic odor due to the
presence of coumarin. Sweet vernal grass
is an erect perennial, about a foot high. An-
other species, A. aristatum Boiss. (.4. puelln
Lee. and Lam.), a low annual, is introduced
at a few localities.
101. PHALAKIS L.
Spikelets laterally compressed, with 1
terminal perfect floret and 2 sterile lemmas
below, disarticulating above the glumes, ar-
. ranged in usually dense spikelike panicles ;
glumes equal, boat shaped, often winged on
the keel; sterile lemmas reduced to 2 small
scales (rarely only 1) ; fertile lemma coriace-
ous, shorter than the glumes,
inclosing the faintly 2-nerved
palea.
Annual or perennial erect
grasses, with flat blades.
Species about 20, in temper-
ate regions of Europe and
America. Nine species are
found in the United States,
four being introduced from
Europe.
Type species : Plialaris canari-
ensis L.
Phalaris L., Sp. PI. 54, 1753;
Gen. PI., ed. 5, 29. 1754. Five
species are described, P. canari-
FIG. 120. Sweet vernal grass, Anthoxantlium odoratum. Plant, X
sterile lemmas, and fertile floret, X 5.
spikelet, two
Bui. 772, U. S. Dept. of Agriculture.
PLATE XV.
SWEET VERNAL GRASS (A NTH ox A NTH DM ODORATUM).
Bui. 772, U. S. Dept. of Agriculture.
PLATE XVI.
GENERA OF GRASSES OF THE UNITED STATES.
203
ensis, P. phleoidcs, P. arundinacea, P. erucaeformis, and P. oryzoides. The
second species is now referred to Phleum, the fourth to Beckmannia, and
the fifth to Homalocenchrus. The first species is chosen as the type, be-
cause this is the one that best corresponds to the description of the genus
in the Genera Plantarum
(e. g., gluma obtusa) and
is moreover the only one
of the five species men-
tioned above that was
known by the name of
Phalaris to the older au-
thors, such as Bauhin.
Typhoides Moench,
Meth. 201. 1794. A single
species, T. arundinacea,
based on Phalaris arundi-
nacea L., is included.
Digraphis Trin., Fund.
Agrost. 127. 1820. A
single species, D. arundi-
nacea, based on Phalaris
arundinacea L., is in-
cluded.
Endallax Rat, Bull. Bot. Seringe
1: 220. 1830. Phalaris arundinacea
is the only species given.
The most important species of
the genus in the United States is
Phalaris arundinacea L., reed
canary grass, a native perennial
found in wet ground in the
cooler parts of the Northern
Hemisphere. The inflorescence
is a rather loose spikelike panicle
2 to 6 inches long. It is an im-
portant constituent of lowland
hay in the region from Mon-
tana to Wisconsin. A vari-
ety (picta L.) with blades
striped with white is grown for
ornament in gardens under the name of ribbon grass or gardener's
garters.
FIG. 121. Canary grass,
canariensis. Plant, X \
and fertile floret with
sterile lemmas, X 5.
Phalaris
; spikelet
tbe two
204 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Phalaris canariensis L. (fig. 121), canary grass, is an annual with
ovoid heads, the large spikelets white with green nerves. This species
is introduced from Europe, where it is grown for seed, which fur-
nishes the canary seed of commerce. 1 Phalaris caroliniana Walt., a
perennial of the southern United States, with oblong compact heads,
is sometimes cultivated for winter forage.
9. ORYZEAE, THE RICE TRIBE.
102. ORYZA L.
Spikelets 1-flowered, laterally compressed, disarticulating be-
low the glumes; glumes 2, much shorter than the lemma, narrow;
lemma rigid, keeled, 3-nerved, sometimes awned ; palea similar to the
lemma, narrower, keeled, but with no midnerve on the back, 2-nerved
close to the margins.
Annual or sometimes perennial swamp grasses, often tall, with flat
blades and spikelets in open panicles. Species about seven, one in
tropical America, the others in tropical Africa and Asia.
Type species : Oryza sativa L.
Oryza L., Sp. PI. 333, 1753; Gen. PL, ed. 5, 155. 1754. A single species, 0.
sativa, is described.
The only important species is Oryza sativa L. (fig. 122), or rice.
This is cultivated in all tropical and warm countries and is one of the
important food plants of the world. There are a large number of
varieties, some with awned, some with awnless spikelets. In the
United States rice is grown under irrigation on the lowland along
the Atlantic -coast of the Southern States, especially in South Caro-
lina and Georgia, and more extensively along the Mississippi River
in Louisiana and on the prairies of southwestern Louisiana and
southeastern Texas.
103. HOMALOCENCHKUS Mieg.
(Leersia Swartz.)
Spikelets 1-flowered, strongly compressed laterally, disarticulating
from the pedicel; glumes wanting; lemma chartaceous, broad, ob-
long, boat shaped, usually 5-nerved, the lateral pair of nerves close
to the margins, these and the keel often hispid-ciliate, the interme-
diate nerves sometimes faint ; palea as long as the lemma, much nar-
rower, usually 3-nerved, the keel usually hispid-ciliate, the lateral
nerves close to the margins, the margins firmly held by the margins
of the lemma ; stamens six or fewer.
Perennial grasses, usually with creeping rhizomes, with flat, sca-
brous blades and open panicles, the spikelets nearly sessile along one
lr The commercial seed may also contain seed of Panicum miliaceum. The seed of
Phalaris canariensis is pale yellow, equally convex on both sides, compressed, and some-
what pubescent. The seed of Panicum miUaceum is brownish or reddish, much more
plump, dorsally flattened on one side, smooth, and faintly nerved.
GENERA OF GRASSES OF THE UNITED STATES.
205
side of the branchlets. Species ten, tropical and temperate regions;
five species in the United States, mostly^ swamp grasses.
Type species: Phalaris oryzoides L.
Homalocenchrus Mieg, Act. Helv.
Phys. Math. 4: 307. 1760. One spe-
cies is referred to the genus with cer-
tainty, another being doubtfully re-
ferred to it. No specific names are
used, but under the first there are two
citations which appear in the Species
Plantarum under Phalaris oryzoides.
Leersia Swartz, Prod. Veg. Ind. Occ.
21. 1788. Three species are de-
scribed, L. monandra, L. hexandra,
and L. oryzoides. Phalaris oryzoides
FIG. 122. Rice, Oryza saliva. Plant, X I ; spikelet, X 5.
L., the basis of the third species, is selected as the type, as this is the oldest
historically.
206 BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE.
Endodia Raf., Neogenyt. 4. 1825. Based on Leersia lenticiilaris, the only
species mentioned.
Aplexla Raf., Bull. Bot. Seringe 1: 220. 1830. A single species, Leersia
virgata (probably a misprint for L. virginica) is included.
All the species of the United States except H omalocenchrus monan-
drus (Swartz) Kuntze, a plant of rich woods in southern Florida and
southern Texas, have creeping rhizomes. Most of them are marsh
grasses. H omalocenchrus monandrus differs from the other species
also in having small glabrous spikelets in which the palea is rounded
on the back and lacks the midnerve, as in rice. In the other species
the palea is strongly compressed-keeled and appears to represent a
bract rather than a prophyllum.
H omalocenchrus virginicus (Willd.) Britton and H. oryzoides
(L.) Poll. (fig. 123) are common throughout the eastern United
States in moist soil, the latter often forming distinct zones of vege-
tation in marshes. The first has spikelets about 3 mm. long and the
main panicle branches solitary ; the second has spikelets about 5 mm.
long and the lower main panicle branches more than one at the node.
These species, because of the very scabrous, adhesive blades, are
called rice cut-grass. The species have no economic importance.
10. ZIZANIEAE, THE INDIAN-RICE TRIBE.
104. ZIZANIOPSIS Doell and Aschers.
Spikelets unisexual, 1-flowered, disarticulating from the pedicel,
mixed on the same branches of the panicle, the staminate below;
first glume wanting;, second glume 7-nerved, short-awned in the
pistillate spikelets; lemma 3-nerved; palea wanting; stamens six;
styles rather long, united; caryopsis obovate, free, coriaceous,
smooth and shining, beaked with the persistent style.
Robust perennial marsh grasses, with stout creeping rhizomes,
broad flat blades, and large open panicles. Species three; two in
South America, one in the United States.
Type species: Zizania microstacJiya Nees.
Zizaniopsis Doell and Aschers.; Doell in Mart. Fl. Bras. 2 2 : 12, pi. 3. 1871.
A single species described.
The only species in the United States is Zizaniopsis miliacea
(Michx.) Doell and Aschers. (fig. 124), growing in swamps from Vir-
ginia to Florida and Texas. Like Zizania palustris, which it some-
what resembles, this species may be gregarious over wide areas. It
has no economic importance except as it may furnish shelter and food
to water birds.
105. ZIZANIA L.
Spikelets unisexual, 1-flowered, disarticulating from the pedicel;
staminate spikelet soft, the first glume wanting, the second 5-nerved,
membranaceous, linear, acuminate or awn-pointed; lemma about as
long as the glume, 3-nerved; palea wanting; stamens 6; pistillate
GENERA OF GRASSES OF THE UNITED STATES. 207
FIG. 123, Rice cut-grass, Homaloccnchrus oryzoides. Plant, X ; spikelet, X 5.
208 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 124. Zizaniopsis miliacea. Plant, X I ; staminate spikelet, pistillate spikelet, and
ripe caryopsis, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 209
spikelet terete, angled at maturity: glumes wanting; lemma charta-
ceous, 3-nerved, tapering into a long slender awn; palea 2-nerved,
closely clasped by the lemma; grain cylindric, as much as 2 cm. long..
Tall annual or perennial aquatic grasses, with flat blades and large
terminal panicles, the lower branches spreading, bearing the pendu-
lous staminate spikelets, the upper branches ascending, at maturity
erect, bearing appressed pistillate spikelets, the staminate spikelets
early deciduous, the pistillate spikelets tardily deciduous. Species
three, one in eastern Asia, two in North America.
Type species: Zissania aquatica L.
Zizania L., Sp. PI. 991, 1753 ; Gen. PI., ed. 5 r 427. 1754. Linnaeus describes
two species, Z. aquatica and Z. terrcstris. The citation in the Genera Plantarum
is to Gronovius. " Zizania Gron. virg. 189 " is given as a synonym by Linnaeus
under Z. aquatica; hence the latter is the type species. The second species, from
Malabar, does not belong to Zizania. The director of the Kew Royal Botanic
(jraraens states that the plate upon which it is based (Rheede, Hort. Malab. 12:
pi. 60) represents Scleria elata Thwaltes.
Fartis Adans., Fam. PI. 2: 37, 557. 1763. Based on Zizania L., which was
not Zizania of the ancients.
Hydropyrum Link, Hort. Berol. 1: 252. 1827. A single species, H. esculen-
tum, based on Zizania palustris L., is included.
Melinum Link, Handbuch Erkenn. Gewachse 1 : 96. 1829. A single species,
M. palustre, based on Zizania palustris L., is included.
Ceratochaete Lunell, Amer. Midi. Nat. 4: 214. 1915. A new name proposed
for Zizania L., "not Zizanion of the New Testament," which is the tares of
Scripture.
Zizania palustris L. (PI. XVI; fig. 125), Indian or wild rice, is an
annual marsh grass growing in the Eastern and Northern States,
often over extensive areas. The seeds were used by the aborigines for
food and are still used to some extent by some of the northern
tribes of Indians. Wild rice is important as a food and shelter for
water birds. It is sometimes planted for this purpose in marshes on
game preserves. Zizania aquatica L. differs in having narrower
blades, shorter culms, and less spreading panicles. This form, found
from Maine to Minnesota, may be a variety rather than a distinct
species. 1 At first Linnaeus did not distinguish between the narrow-
leaved and broad-leaved forms, but based the name aquatica on a
specimen 2 of the narrow-leaved form. Later (1771) he described the
broad-leaved form as Zizania palustris. The Asiatic Z. latifolia
Turcz. is a perennial with rhizomes and stolons.
106. LUZIOLA Juss.
Spikelets unisexual, 1-flowered, disarticulating from the pedicel,
the staminate and pistillate flowers in separate panicles on the same
plant ; first glume and palea wanting ; second glume and lemma about
equal, thin, several to many nerved, lanceolate or oblong; stamens
several ( " 6 to 18 " ) ; stigmas long, plumose ; grain free, globose,
smooth.
l See Smiths. Misc. Coll. 68 12 : 35. 1918.
2 See Hitchcock, Contr. U. S. Nat. Herb. 12: 124. 1908,
97769 19 Bull. 772 14
210 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIQ. 125. Wild rice, Zizania palustris. Plant, X I ; pistillate spikelet, X 2 ; a second
view, X 5 ; staminate spikelet, X 5,
GENERA OF GRASSES OF THE UNITED STATES. 211
Perennial, creeping, low or delicate grasses, with narrow, flat blades
and terminal and axillary panicles. Species about six, in tropical
America ; two species in the southern United States.
Type species: Luziola peruriann Gmel.
Luzioln Juss. ; Gmel. Syst. Nat. 2: 637. 1791. The genus is first described
by Jussieu in his Genera Plantarum (1789), but no specific name *s mentioned.
Ginelin assigns a specific name to the species described by Jussieu.
There are two species in the United States, Luziola peruviana
(fig. 126), with fruit 2 mm. long, and L. cdabamemis Chapm., with
fruit 4 mm. long, the former from Florida to Louisiana and the latter
from Alabama. They have no economic importance.
107. HYDBOCHLOA Beauv.
Spikelets unisexual, 1-flowered, awnless, disarticulating from the
pedicel, the plants monoecious; staminate spikelets with a thin
7-nerved lemma, a 2-nerved palea, and 6 stamens, the glumes want-
ing; pistillate spikelets with a thin 3-nerved second glume and 5-
nerved lemma, the first glume and the palea wanting, the stigmas
long and slender.
A slender, branching, aquatic grass, probably perennial, the leaves
floating; staminate flowers in a small few-flowered terminal spike;
pistillate flowers in few-flowered spikes in the axils of the leaves.
Species one, in the southeastern United States.
Type species : Hydrocliloa carolincnsis Beauv.
Hydrocliloa Beauv., Ess. Agrost. 135, pi. 24, f. 4. 1812. Beauvois figures one
species, which he names H. carolinensis. The species was first described as
Zizania flnitans Michx., but this name can not be transferred to Hydrochloa
because of H. fluitans Host.
The spikelets of each sex possess but two bracts. From the ap-
pearance and nervation it is assumed that the palea is present in the
staminate spikelets and wanting in the pistillate.
Ilydrochloa ccvrolinensis Beauv. (fig. 127) is found in streams and
ponds from South Carolina to Florida and Louisiana, sometimes in
sufficient abundance to become troublesome. It has no economic im-
portance.
Pharus L., Syst. Nat., ed. 10, 2: 1269. 1759. A tropical American
genus, one species of which, P. latifolius L., was included by Chap-
man in his Flora of the Southern States. The locality given is
"Orange Lake, Florida (Herb. Thurber)." This West Indian spe-
cies has not been observed by others in Florida and it should be
credited to the United States with doubt.
Rather tall monoecious perennials, with broad elliptic or oblanceo-
late, petiolate blades and terminal panicles, the large terete pistillate
spikelets appressed along the rather few stiffly spreading branches,
212 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
these disarticulating at the base and easily detached, the imcinate
fruits acting like burs.
FIG. 126. Luziola, peruviana. Plant, X i ; pistillate and staminate spikelets, X 5.
11. MELINIDEAE, THE MOLASSES-GRASS TRIBE.
Melinis Beauv., Ess. Agrost. 54, pi. 11, f. 4. 1812. A Brazilian
genus. Melinis minutiflora Beauv. (molasses grass) is cultivated in
GENERA OF GRASSES OF THE UNITED STATES.
213
the Tropics for forage. It has been tried in the warmer parts of the
South. Molasses grass is a rather stout perennial, with viscid-pubes-
cent foliage, and narrow many-flowered panicles of very small
awned spikelets.
FIG. 127. Hydrochloa carolinensis. Plant, X \ ; two views of pistillate spikelet, X 5 ;
stamina te spikelet, X 5.
12. PANICEAE, THE MILLET TRIBE.
108. ANTHAENANTIA Beauv. 1
Spikelets obovoid; first glume wanting; second glume and sterile
lemma about equal in length, broad, 5 -nerved, villous, the sterile
lemma with a small palea and sometimes with a staminate flower;
fertile lemma cartilaginous, boat shaped, 3-nerved, subacute, chest-
1 For a discussion of this and the following genera of this tribe, see Chase, Proc. Bioi.
Soc. Washington, 19:183-192, 1906; 21:1-10, 1908; 21:175-188, 1908; 24:103-160,
1911.
214 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
nut brown, as long as the glume, the pale margins very narrow, in-
folding the palea its entire length.
Perennial erect grasses with short
creeping rhizomes, narrow, firm, flat
blades, the uppermost much reduced, and
narrow panicles, the slender branches
ascending or appressed. Species two, on
the Coastal Plain of the southeastern
United States.
Type species: Phalaris rillosa Michx.
Anthaenaiitia Beauv., Ess. Agrost. 48, pi. 10,
f. 7. 1812. Phalaris villosa is the only species
mentioned.
Aulaxanthus Ell., Bot. S. C. and Ga. 1: 102.
1816. Two species are described, A. ciliatus and
A. rufus. The first, which
is the same as Anthaenantia
villosa, is accepted as the
type.
Aulaxia Nutt, Gen. PI. 1:
47. 1818. Nuttall changes
Elliott's name Aulaxanthus
to Aulaxia.
Anthaenantia villosa
(Michx.) Beauv. (fig.
128), with comparatively
short, spreading blades
and usually pale panicle,
and A. rufa (Ell.)
Schult., with long erect
blades and usually pur-
ple panicle, are of no
economic importance.
FIG. 128. Anthaenantia villosa. Plant, X I ; spikelet and fertile floret, X 10.
109. VALOTA Adans.
Spikelets lanceolate, in pairs, short-pediceled, in two rows along
one side of a narrow rachis; first glume minute, glabrous;
GENERA OF GRASSES OF THE UNITED STATES. 215
second glume and sterile lemma about as long as the fruit, 3 to
5 nerved, copiously silky; fertile lemma cartilaginous, lanceolate,
acuminate, usually brown, the flat white hyaline margins broad.
Perennial grasses, the slender racemes erect or nearly so, aggregate
along the upper part of the main, axis, forming a white or brownish
woolly panicle. Species about 12, in the warmer parts of America
and in Australia ; 3 species in the southern United States.
Type species: Andropogon insularia L.
Valota Adans., Fam. PI. 2 : 495. 1763. The citation given by Adanson is to
" Sloan, t. 14. f. 2." which is also given by Linnaeus under his Andropogon in-
sularis, 1 which fixes this species as the type.
Trichachne Nees, Agrost. Bras. 85. 1829. Nees describes five species, the first
of which, T. insularis, based on Andropogon insularis, is taken as the type.
Valota is closely allied to Syntherisma, differing chiefly in the
acuminate fruit and the silky spikelets.
Valota insuldrls (L.) Chase (Panicum lanatwm Rottb., P. leuco-
pJiaeum H. B. K.) (fig. 129), common in the American Tropics, with
brown or tawny inflorescence, is found in southern Florida. Valota
hitchcockii Chase, with short blades and short-pubescent spikelets is
a rare species from Texas and Mexico. Valota saccharata (Buckl.)
Chase (Panicum lachnanthum Torr.), with copiously long, silky
white spikelets, is common in the Southwestern States on rocky soil.
The first-mentioned species is not relished by cattle and in the West
Indies is called sour-grass. 'The third species is a constituent of the
ranges of the Southwest, but furnishes only fair forage.
110. SYNTHEKISMA Walt., the crab-grasses.
(Digitaria Hall., not Heist.)
Spikelets solitary or in twos or threes, subsessile or short-pedi-
celed, alternate in two rows on one side of a three-angled winged or
wingless rachis; spikelets lanceolate or elliptic, plano-convex; first
glume minute or wanting; second glume equaling the sterile lemma
or shorter ; fertile lemma cartilaginous, the hyaline margins pale.
Annual or sometimes perennial, erect or prostrate grasses, the slen-
der racemes digitate or somewhat scattered, but aggregate along the
upper part of the culms. Species about 60, in the warmer parts of the
world; 12 species in the United States, mostly in the southeastern
part.
Type species : Syntherisma praecox Walt.
Digitaria Hall., Stirp. Helv. 2: 244, 1768, not Adans., 1763, nor Heist., 1759.
Haller describes two species. No specific names are used, but the first species is
associable by citation with . Panicum sanguinale L. (Syntherisma sanguinalis)
Mid the second with Panicum dactylon L. (Capriola dactylon}. The first is
chosen as the type.
Syntherisma Walt., Fl. Carol. 76. 1788. Walter describes three species, 8.
praecox, S. serotina, and 8. villosa. The first of these is selected as the typo.
This is the same as 8, sanguinalis.
1 Syst. Nat., ed. 10, 2: 1304. 1759.
216 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTUREo
FIG. 129. Sour-grass, Valota insularis. Plant, X i ; spikelet and fertile floret, X 10.
GENERA OF GRASSES OF THE UNITED STATES.
217
Syntherisma is included in Panicum by some botanists and in Pas-
palum by others. It differs from both in the cartilaginous rather
than indurate fruit and in
the flat, white, hyaline
margins of the lemma.
Our commonest species
is Syntherisma, sanguincdis
(L.) Dulac (Dig it aria
sanguinalis Scop.) ( fig.
130), usually called crab-
grass. This is a decumbent
or prostrate annual, usually
more or less purple, with
hispid sheaths, flat blades,
few to several slender digi-
tate or subdigitate spikes
or racemes, and a narrowly
winged rachis, the first
glume minute. Crab-grass
is a native of the Old
World, but is now widely
distributed in tropical
America, and is common in
cultivated soil throughout
the eastern and southern
part of the United States.
It is often a bad weed in
lawns. In the Southern
States, where crab-grass
produces an abundant
growth in the late summer
on the fields from which
crops have been gathered,
FIG. 130. Crab-grass, Syntherisma sangwnaUs. ft is utilized for forage and
"Plant- V 1 -ftirrt Trfck-wrc? f\f arvllr^lo-f n-n/1 -P^-n-f -il^ ^
Plant, X \ ; two views of spikelet and fertile
floret, X 10.
is sometimes cut for hay.
218 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Syntherisma ischaemum (Schrad.) Nash (Digitaria humifusa
Pers., Panicum glabrum Gaud.), also introduced, is darker green and
glabrous, and has dark pubescent spikelets, the first glume wanting.
This is a common weed in lawns. Syrtfherisma fiUfo?*mis (L.) Nash
is an erect native annual with erect racemes, the rachis not winged.
Several other species are found in Florida. Nearly all the species of
Syntherisma are weedy grasses or tend to become weeds.
For a revision of the species of Syntherisma found in the United
States, see Nash, Bull. Torrey Club 25: 289-303. 1898.
111. LEPTOLOMA Chase.
Spikelets on slender pedicels; first glume minute or obsolete; sec-
ond glume 3-nerved, nearly as long as the 5 to 7 nerved sterile lemma,
a more or less prominent stripe of appressed silky hairs down the
internerves and margins of each, the sterile lemma empty or inclos-
ing a minute nerveless rudimentary palea; fertile lemma cartilagi-
nous, elliptic, acute, brown, the delicate hyaline margins inclosing
the palea.
Perennial branching grasses, with brittle culms, felty pubescent
at base, flat blades, and open or diffuse panicles, these breaking away
at maturity, becoming tumbleweeds. Species four; one in the United
States, the others in Australia.
Type species : Panteum cognatum Schult.
Leptoloma Chase, Proc. Biol. Soc. Washington 19: 191. 1906. The type is
designated.
The only species found in our country is Leptoloma cognatum
(Schult.) Chase (Panicum autumnale Bosc, P. divergens Muhl.)
(fig. 131) growing in sandy soil from New England to Florida ^and
from Minnesota to Texas. This genus differs from Syntherisma
chiefly in the form of the inflorescence, being an open panicle rather
than an aggregation of slender spikes. It is of no economic impor-
tance.
112. STENOTAPHRUM Trin.
Spikelets embedded in one side of an enlarged and flattened corky
rachis disarticulating at maturity, the spikelets remaining attached ;
first glume small ; second glume and sterile lemma about equal, the
latter with a palea or staminate flower ; fertile lemma chartaceous.
Creeping stoloniferous perennials, with short flowering stems,
rather broad and short obtuse blades, and terminal and axillary
spikes. Species about five ; islands of the Pacific ; one in the southern
TJnited States.
Type species : Panicum dimidiatum L.
Stenotaphrum Trin., Fund. Agrost. 175. 1820. A single species is mentioned,
8. glabrum, Trin., based on Rottboellia dimidiata L., which in turn is based on
Panicum dimidiatum L.
GENERA OF GRASSES OF THE UNITED STATES.
219
Our species is Stenotaphrum secimdatum (Walt.) Kuntze (S.
americanum Schrank) (fig. 132), found near the coast from North
Carolina to Florida and Texas, and southward, growing especially
FIG. 131. Leptoloma cognatum.
Plant, X s ; two views of spike-
let and fertile floret, X 10.
in alluvial or mucky soil. It is culti-
vated as a lawn grass in the coastal
cities under the name of St. Augus-
tine grass. The lawns of this grass
have a coarse texture but are other-
wise satisfactory. The grass is prop-
agated by setting out cuttings or
pieces of the stolons bearing shoots.
113. ERIOCHLOA H. B. K.
Spikelets dorsally compressed,
more or less pubescent, solitary or
sometimes in pairs, short-pediceled
or subsessile, in two rows on one side
of a narrow, usually hairy rachis,
the pedicels often clothed with long,
stiff hairs, the back of the fertile
lemma turned from the rachis; lower
rachilla joint thickened, forming a
more or less ringlike, usually dark-
colored callus below the second
glume, the first glume reduced to a
minute sheath about this and adnate
to it ; second glume and sterile lemma
about equal, acute or acuminate,
the lemma usually inclosing a hya-
line palea or sometimes a stami-
220 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
nate flower; fertile lemma indurate, minutely papillose-rugose,
mucronate or awned, the awn often readily deciduous, the mar-
gins slightly inrolled.
Annual or perennial, often
branching grasses, with termi-
nal panicles consisting of sev-
eral or many spreading or
appressed racemes, usually
rather closely arranged along
the main axis. Species about
15, in the warmer parts of the
world, mostly in America; 6
species in the United States, in
the Southern and Southwest-
ern States.
Type species: EriocMoa distachya
H. B. K.
Eriochloa H. B. K., Nov. Gen. and
Sp. 1 : 94, pis. 30 and 31. 1816. Two
species are described, E. distachya
and E. polystachya, and both are
figured. The first is chosen as the
type.
Helopus Trin., Fund. Agrost. 103,
pi. 4. 1820. The only species men-
tioned is H. pilosus, which is the
FIG. 132. St. Augustine grass, Stenotaphrum secundatum. Plant, X \ ; two views of
spikelet and fertile floret, X 10.
same as Eriochloa punctata. Trinius incorrectly cites Milium ramosum Retz.
as a synonym of Helopus pilosus.
Oedipachne Link, Hort. Berol. 1: 51. 1827. The only species mentioned is
Milium punctatum L. (Eriochloa punctata (L.) Hamilt), upon which Oedi-
pachne punctata is based.
GENERA OF GRASSES OF THE UNITED STATES. 221
Our commonest species is Eriochloa acuminata (Presl) Kunth, an
annual, 1 to 2 feet tall, with spikelets about 5 mm. long, the fertile
lemma apiculate. This is found from Kansas to Texas and Arizona,
in open ground, often a weed in cultivated soil. In some books this
is called E. polystachya H. B. K., a species described from Ecuador.
A West Indian species, E. punctata (L.) Hamilt. (fig. 133), extends
into Louisiana and Texas.
Our species appear to be of no agricultural importance. One
species of the West Indies (E. subglabra), called in Porto Rico
malojilla, is used for forage. This has been tried along the Gulf
coast from Florida to southern Texas, and has given excellent results
in southern Florida and at Biloxi, Miss. Carib grass, as it is pro-
posed to call this species, is similar in habit to Para grass, producing
runners, but less extensively, and is suited to grazing and will
furnish a good quality of hay. It will not withstand either cold or
drought.
114. BEACHIABIA (Trin.) Griseb.
Spikelets dorsally compressed, solitary, rarely in pairs, subsessile,
in two rows on one side of a 3-angled, sometimes narrowly winged
rachis, the first glume turned toward the axis; first glume short or
nearly as long as the spikelet ; second glume and sterile lemma about
equal, 5 to 7 nerved, the lemma inclosing a hyaline palea and some-
times a staminate flower; fertile lemma indurate, usually papillose-
rugose, the margins inrolled, the apex rarely mucronate or bearing a
short awn.
Annual or perennial,, branching and spreading grasses, with linear-
blades and terminal inflorescence consisting of several spreading or
appressed racemes along a common axis. Species about 15, in the
warmer regions of both hemispheres; 3 species in the United
States, 2 native along our southern border, 1 introduced.
Type species : Panicum erucaeforme J. E. Smith.
Brachiaria Griseb., in Ledeb. Fl. Ross. 4: 469. 1853. Only one species is
mentioned, B. crucaeformis.
From those species of Panicum with spikelets in one-sided spike-
like racemes, this genus differs in having the spikelets in the reverse
position relative to the rachis, that is, with the first glume toward the
rachis.
The three species, none of which has economic importance, are
Brachiaria erucaeformis (J. E. Smith) Griseb., an annual, with
pubescent spikelets, occasionally introduced from Europe, B. platy-
phylla (Griseb.) Nash (fig. 134), an annual, with glabrous spikelets,
growing in Louisiana and Texas, and B. ciliatissima (Buckl.) Chase
(Panicum ciliatissimwm Buckl.), a perennial, with silky spikelets,
growing in Arkansas and Texas,
222 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 133. Eriochloa punctata. Plant, X h ', two views of spikelet and fertile floret, X 10.
GENERA OF GRASSES OF THE UNITED STATES.
223
115. AXONOPUS Beauv.
(Anastrophus Schlecht.)
Spikelets depressed biconvex, not turgid, oblong, usually obtuse,
solitary, sessile, and alternate, in two rows on one side of a 3-angled
rachis, the back of the fertile lemma turned
from the axis ; first glume wanting ; second
glume and sterile lemma equal, the lemma
without a palea; fertile lemma and palea
indurate, the lemma oblong-elliptic, usually
obtuse, the margins slightly inrolled.
Stoloniferous or tufted perennials, rarely
annuals, with usually flat or folded, ab-
ruptly rounded or.somewhat pointed blades,
and few or numerous, slender, spikelike
racemes, digitate or racemose along the
main axis. Species about 30, tropical
America, 1 or 2 introduced into the
Tropics of the Old World; 2 species in
the United States, in moist
soil in the Southeastern
States.
Type species: Milium compres-
sitm Swartz.
Axonopus Beauv., Ess. Agrost.
12, 154. 1812. Beauvois mentions
several diverse species that be-
long to his new genus, the first
being Milium compressum, which
FIG. 134. Brachiaria platyphulla. Plant, X \ ; two views of spikelet and fertile floret,
X 10.
224 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
is chosen as the type, since it is the only species that agrees with his de-
scription of the genus in having solitary spikelets. The other species
that he mentions are now referred to other genera,
Milium digitatum to Syntherisma, M. cimicinum to
Coridochloa, M. paniceum to Syntherisma. In a
subsequent paragraph the author briefly describes
a new species, A. aureus, which he thinks ought
to belong to this genus. Nash 1 selects A. aureus
as the type of Axonopus.
Cabrera Lag., Gen. and Sp. Nov. 5. 1816. The
type is C. chrysoblepharis Lag., the only species
mentioned. To this group belongs Axonopus aureus
mentioned above.
Anastrophus Schlecht., Bot. Zeit. 8: 681. 1850.
The type is Paspalum platyculmum Du Petit-Thou.,
the first of several species referred to the genus.
This is probably the same as Axonopus compressus,
or at least closely allied to that species.
Lappagopsis Steud., Syn. PI. Glum. 1 : 112. 1854.
The type is L. bijuga Steud., the only species de-
scribed.
The most important species of the genus
in the United States is Axonopus compres-
sus (Swartz) Beauv. (fig. 135),
usually called carpet grass in the
South. This is a stolonif erous per-
ennial, with compressed stems,
comparatively short, flat, broadly
linear, abruptly pointed blades,
and slender spikes somewhat digi-
tate at the summit of the culms.
Carpet grass is common in the
Tropics and extends in the United
States from Virginia to Florida
and Texas in the lowland along
the coast. It thrives particularly
in alluvial or mucky open ground,
where it becomes the dominant
FIG. 135. Carpet grass, Axonopus compressus. Plant, X \ ; two views of spikelet and
fertile floret, X 10.
grass. Carpet grass is the predominant pasture grass in the region
mentioned, but is of little importance on sandy soil and does not thrive
on the uplands. In the region where it thrives as a pasture grass
Amer. Fl. 17: 165. 1912.
GENERA OF GRASSES OF THE UNITED STATES. 225
it may be utilized as a lawn grass. For this purpose it is propa-
gated by setting out pieces of the stolons. It soon spreads and
occupies the space between.
A second species of the genus, A. fwrcatus (Fliigge) Hitchc., is
found over about the same range as the preceding, but confined to
the United States. This is infrequent and is usually of no economic
importance, but is a valuable pasture grass in the Kissimmee region,
Fla. It is distinguished by its larger spikelets, 4 to 6 mm. long.
116. REIMAROCHLOA Hitchc.
(Reimaria of authors.)
Spikelets strongly dorsally compressed, lanceolate, acuminate,
rather distant, subsessile, and alternate in two rows along one side
of a narrow, flattened rachis, the back of the fertile lemma turned
toward it; both glumes wanting, or the second sometimes present in
the terminal spikelet; sterile lemma about equaling the fruit, the
sterile palea obsolete ; fertile lemma scarcely indurate, faintly nerved,
acuminate, the margins inrolled at the base only, the palea free nearly
half its length.
Spreading or stoloniferous perennials, with flat blades and slender
spikes, these subdigitate or racemose along the upper part of the culm,
stiffly spreading or reflexed at maturity. Species about four; in the
American Tropics, one extending into Florida.
Type species : Reimaria acuta Fliigge.
Reimarochloa Hitchc., Contr. U. S. Nat. Herb. 12: 198. 1909. The type is
designated. The genus includes most of the species that have been assigned to
Reimaria Fliigge, the type of which is R. Candida, a species of Paspalum.
Only one species is found in the United States, Reimarochloa
oligostacJiya (Munro) Hitchc. (fig. 136), confined to Florida and
Cuba. It has no economic importance.
117. PASPALUM L.
Spikelets plano-convex, usually obtuse, subsessile, solitary or in
pairs, in two rows on one side of a narrow or dilated rachis, the back
of the fertile lemma toward it; first glume usually wanting; second
glume and sterile lemma commonly about equal, the former rarely
wanting; fertile lemma usually obtuse, chartaceous-indurate, the
margins inrolled.
Mostly perennials, with one to many spikelike racemes, these single
or paired at the summit of the culms or racemosely arranged along
the main axis. Species numerous, probably as many as 200, widely
distributed in the warmer parts of both hemispheres; about 50 spe-
cies in the United States, mostly in the Southeastern States.
Type species: Paspalum dimidiatum L.
Paspalum L., Syst. Nat. ed. 10, 2: 855, 1759. Four species are described, P. di-
midiatum (of which " Panicum dissectum sp. pi. 57 n, (? " is cited as, a syno-
97769 19 Bull. 772 15
226 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
nym), P. virgatum, P. paniculatum, and P. distichum. The first is selected as
the type. All are still retained in the genus.
FIG. 136. Reimarochloa oligostachya. Plant X I ; two views of spikelet and fertile
floret, X 10.
Ceresia Pers., Syn. PI. 1 : 85. 1805. A single species, C. elegans Pers., is
included. This is one of the species having a broad-winged rachis.
Reimaria Fliigge, Gram. Monogr. 213. 1810. Three species are included,
R. Candida Humh. and Bonpl., .R. elepans, and R. acuta* The first two are
GENEKA OF GRASSES OF THE UNITED STATES. 227
species of Paspalum in which both glumes are wanting, the third, to which the
generic description less aptly applies, is a species of Reimarochloa. Reimaria
Candida is taken as the type.
Cymatochloa Schlecht, Bot. Zeit. 12 : 817, 821. 1854. Two names, " C. fluir
tans (Ceresia fluitaus Ell.)" and " C. repens (Paspalum repens Berg.)" are
given. Both names apply to the same species, Paspalum repens Berg.
Dimorphostachys Fourn., Compt Rend. Acad. Sci. (Paris) 80: 441. 1875.
The type is Panicum monostachyum H. B. K., the first of four species men-
tioned.
Paspalum is closely allied to Panicum, differing chiefly in the
strictly racemose inflorescence and the plano-convex spikelets in
which the first glume is wanting. In a few species (section Dimor-
phostachys, in Paspalum distichum and in P. bifidum (Bertol.)
Nash) the first glume is present on at least a part of the spikelets.
In P. pulchellum Kunth of tropical America and a few other species
both glumes are wanting.
In spite of the large number of species in this genus, very few
are of economic importance. Most of the species make a sparse
growth in moist pine barrens and old fields and are not grazed to
any extent. A few species inhabiting meadows and savannas fur-
nish a limited amount of forage. Among these may be mentioned
P. laeve Michx. (fig. 137) and P. ciliatifolium Michx., and the allies
of these species. Paspalum laeve, with 2 or 3 racemes and spikelets
2.5 mm. long, is common from Maryland to Florida and Texas.
Paspalum ciliatifolium and its allies, besides the one to few slender
racemes on the main culm, have several naked branches from the
upper sheaths, each branch usually bearing a single raceme.
Paspalum distichum L., with creeping stolons and racemes in
pairs at the summit of the culms, is widely distributed along muddy
coasts and ditch banks from Virginia to Florida and thence across
the continent to California and Washington. Where abundant it
furnishes some forage.
Paspalum dilatatum Poir. has been tried as a forage grass in the
Southern States, where it has been cultivated under the name of
water grass. It has little to recommend it here, but in the Hawaiian
Islands it gives much promise as a pasture grass. In tropical Amer-
ica species of Paspalum form an important element in the grazing
land of the savannas, P. notatum Fliigge being one of the most
abundant.
118. PANICUM L.
Spikelets more or less compressed dorsiventrally, arranged in open
or compact panicles, rarely racemes; glumes 2, herbaceous, nerved,
usually very unequal, the first often minute, the second typically
equaling the sterile lemma, the latter of the same texture and simu-
lating a third glume, bearing in its axil a membranaceous or hyaline
palea and sometimes a staminate flower, the palea rarely wanting;
228 BULLETIN" 772, TJ. S. DEPARTMENT OF AGRICULTURE.
fertile lemma chartaceous- indurate, typically obtuse, the nerves
obsolete, the margins inrolled over an inclosed palea of the same tex-
FIG. 137. Paspalum laeve. Plant, X \ ; two views of spikelet and fertile floret, X 10.
ture, a lunate line of thinner texture at the back just above the base,
the rootlet protruding through this at germination.
GENERA OF GRASSES OF THE UNITED STATES. 229
Annual or perennial grasses, of various habit. Species probably
about 500, mostly confined to the warmer regions of both hemi-
spheres, about 150 species being found in the United States.
Type species : Panicum miliaceum L.
Panicum L., Sp. PI. 55, 1753 ; Gen. PI., ed. 5, 29. 1754. Twenty species are
described. The first ten and the fifteenth are now referred to other genera. Of
the species considered typical by Linnaeus, as indicated by the description in
his Genera Plantarum, Panicum miliaceum is the only one cultivated and is
therefore chosen as the type. 1
Eatonia Raf., Journ. de Phys. 89: 104. 1819. A single species, E. purpura-
scens, which is the same as Panicum virgatum, is included.
Steinchisma Hal, Bull. Bot. Seringe 1 : 220. 1830. " Panicum divaricatum, P.
hians " are cited, both names applying to the same species, P. Mans Ell.
Phanopyrum (Raf.) Nash, in Small, Fl. Southeast. U. S. 104. 1903. Based
on " Panicum, subgenus Phanopyrum Raf.," with a single species, P. gymnocar-
pon (Ell.) Nash.
Chasea Nleuwl., Amer. Midi. Nat. 2: 64. 1911. A new name proposed for
" Panicum of the authors not of Linnaeus or only in part," the name Panicum
being applied to Chaetochloa.
Among the species of the United States two subgenera are recog-
nized, besides Panicum proper.
Subgenus Paurochaetium Hitchc. and Chase. Perennials with
tufted culms, erect narrow blades, narrow, more or less spikelike
inflorescence, the ultimate branchlets produced beyond the uppermost
spikelets as a bristle 1 to 6 mm. long, the apiculate fruits transversely
rugose. There are four species within our limits, one from Florida,
three from Texas. This subgenus shows a transition to Chaetochloa.
Subgenus Dichanthelium Hitchc. and Chase. Perennials forming
a usually well-marked rosette of winter leaves, having a vernal phase
of simple culms and terminal panicles of small, perfect, but usually
sterile spikelets, and an autumnal phase produced by the branching
of the culms after the maturity of the primary panicles, the sec-
ondary leaves and panicles usually much reduced, the spikelets cleis-
togamous and fruitful, sometimes hidden in the sheaths. There are
105 species within our limits, the species being especially abundant
on the Atlantic Coastal Plain. A representative of this subgenus is
Panicum dichotomum L. (fig. 138). A common species in the East-
ern States is P. clandestinum L. (PI. XVII), one of the most robust
representatives of the group. This has bristly sheaths and cordate
clasping blades as much as an inch wide. It grows in moist soil and
furnishes a moderate amount of forage.
The remaining species belong for the most part to true Pani-
cum, called by some the subgenus Eupanicum. The more important
of these are the following: Panicum barbinode Trin., Para grass, a
perennial with stout stolons as much as 15 feet long, culms 3 to 6 feet
tall from a creeping base, bearded nodes, and panicles 4 to 6 inches
long, consisting of several spikelike racemes of glabrous spikelets
1 For a full discussion of the type species of Panicum, see Hitchcock and Chase, Contr.
U. S. Nat. Herb. 15: 13. 1910.
230
BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
3 mm. long. It is com-
monly cultivated in tropi-
cal America for forage
and has been introduced
for this purpose in Flor-
ida and southern Texas
and also into the Tropics
of the Old World. In
Porto Rico it is called
malojilla. This species
has been incorrectly re-
ferred to P. molle Swartz.
A field of Para grass
soon becomes a tangle of
stolons and the decumbent
bases of the stems, and for best results it
must be renewed by plowing or disking.
Panicum maximum Jacq., guinea grass,
is a perennial erect bunch-grass, 4 to 6
feet tall, with open spreading panicles
of elliptic spikelets about 3 mm. long,
the fruit rugose. This is a native of
Africa, introduced into tropical America,
where it is cultivated for forage, fur-
nishing pasture and green feed. It is
said to have been introduced into Ja-
maica from west tropical Africa in 1774.
These two species, Para grass and guinea
grass are the only grasses that are ex-
FIG. 138. Panicum dicJwto- tensively cultivated for forage in tropi-
mum. Plant, x i ; two cal America. Panicum miliaceum L.,
views of spikelet and fertile -11 j. i -n ^ i
floret, x 10. proso millet, broom-corn millet, hog
millet, an erect annual 2 to 3 feet tall,
with a drooping panicle, is cultivated in Europe for the seed, which
is used for food. It is sparingly cultivated in this country for forage.
Bui. 772, U. S. Dept. of Agriculture.
PLATE XVII,
PANICUM CLANDESTINUM.
Common in moist woods. Useful for forage and for ornament.
Bui. 772, U. S. Dept. of Agriculture
PLATE XVIII,
EULALIA (MlSCANTHUS SINENSIS). GROWN FOR ORNAMENT
GENERA OF GRASSES OF THE UNITED STATES.
231
Panicum virgatum L. (fig. 139) switch-grass, an erect perennial 3 to
5 feet tall, with open spreading panicle, is common in the eastern half
Fio. 139. Switch-grass, Panicum virgaiwm. Plant, X I ; two views of spikelet and
fertile floret, X 10.
of the United States. It is a constituent of prairie hay. Panicum
bulbosum H. B. K., of the Southwest develops well-marked corms
232 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
at the base of the culms. Panicum texanum Buckl., Texas millet,
Colorado grass, is an annual rather weedy grass of Texas that has
been utilized for hay. It has been called Colorado grass because it
grows in the valley of the Colorado River. Panicwn dichotomi-
florum Michx. is a smooth, annual, much-branched, rather succulent
weed, common in the eastern United States in the autumn. The
first glume is very short and truncate. Panicum capillare L. (fig.
140), old- witch grass, is an annual weed, with hirsute sheaths and a
relatively large open capillary panicle with small spikelets. At
maturity the panicle breaks away and is blown about by the wind
as a tumble grass. Panicum geminatum Forsk. (fig. 141), a common
tropical species, extends into Florida and Texas.
Besides the two subgenera there are a few species that can not be
included in true Panicum. Two of these within our range are of
some importance. Panicum obtuswn H. B. K. (fig. 142), a forage
grass of the Southwest, producing long wiry stolons with bearded,
swollen nodes, and short, erect, fertile culms with narrow panicles of
obtuse spikelets, is called grapevine mesquite, because of the long,
tough stolons, and adobe grass, because it is found on slightly alka-
line soil. This species differs from Eupanicum in the long first
glume and the racemose branches of the inflorescence. Panicum
kemitomon Schult., maiden cane, is found in moist soil, often in
the water, from Texas to Florida and Delaware near the coast. It
produces extensively creeping rhizomes and numerous sterile shoots.
The panicle is narrow, with short appressed branches. On account
of the rhizomes it becomes a troublesome weed in cultivated soil,
especially in Florida. This species differs from Eupanicum in the
less chartaceous fruit with the palea free at the tip. The seeds of
Panicum sonorum Beal are used for food by the Cocopa Indians.
See Williams, U. S. Dept. Agr., Farmers' Bull. 101, 1899; Scrib-
ner, U. S. Dept. Agr., Div. Agrost. Bull. 20, fig. 23, 1900; Hitch-
cock and Chase, Contr. U. S. Nat. Herb. 15, 1910. The last work
is a revision of the genus Panicum in North America and gives full
descriptions and synonymy of all the species.
119. LASIACIS (Griseb.) Hitchc.
Spikelets subglobose, placed obliquely on their pedicels ; first glume
broad, somewhat inflated-ventricose, usually not over one-third the
length of the spikelet, several-nerved; second glume and sterile
lemma about equal, broad, abruptly apiculate, papery-chartaceous,
shining, many-nerved, glabrous, or lanose at the apex only, the lemma
inclosing a membranaceous palea and sometimes a staminate flower ;
fertile lemma white, bony-indurate, obovoid, obtuse, this and the
palea of the same texture, bearing at the apex in a slight crateriform
GENERA OF GRASSES OF THE UNITED STATES. 233
FIG. 140. Old-witch grass, Panicum capillcwe. Plant, X I ; two views of spikelet and
fertile floret, X 10.
234 BULLETIN 7*72, U. S. DEPARTMENT OF AGRICULTURE.
depression a tuft of woolly hairs, the palea concave below, gibbous
above, the apex often free at maturity.
FIG. 141. Panicum geminatum. Plant, X i ; two views of spikelet and fertile floret
X 10.
Large branching perennials, with woody culms often clambering
several feet high into shrubs or trees, the blades firm, flat, usually
GENERA OF GRASSES OF THE UNITED STATES. 235
lanceolate and narrowed into a petiole, the spikelets in an open
panicle. Species about 20; in the American Tropics, one extending
into southern Florida.
FIG. 142. Grapevine mesquite, Panicum obtusum. Plant, X I \ spikelet and fertile
floret, X 10.
236 BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE.
Type species: Panicum divaricatum L.
Panicum, section Lasiacis Griseb, Fl. Brit. W. Ind. 551.
included, the first of which is P. divaricalum.
Lasiacis Hitchc., Contr. U. S. Nat. Herb. 15 : 16.
1864. Five species
1910. The type is desig-
nated. This genus was previously
included as a section in Panicum,
from which it differs in habit, the
woody culms resembling those of
bamboos, and in the oblique spike-
lets with the woolly apex of the
fruit and the gibbous fertile palea.
The only species in the
United States is Lasiacis dr-
varicata (L.) Hitchc. (fig.
143) of southern Florida. It
has no economic value.
120. SACCIOLEPIS Nash.
Spikelets oblong-conic ;
first glume small, much
shorter than the spikelet ; sec-
ond glume broad, inflated-
FIG. 143. Lasiaois divaricata. Fascicle of branches,
X 1; spikelet and -fertile floret, X 10.
saccate, strongly many-nerved; sterile lemma narrower, flat, fewer
nerved, its palea nearly as long, often subtending a staminate flower ;
fertile lemma stipitate, elliptic, chartaceous-indurate, the margins in-
rolled, the palea not inclosed at the summit.
GENERA OF GRASSES OF THE UNITED STATES.
237
Annuals or perennials, of wet soil, usually branching, the inflores-
cence a dense, usually elongate, spikelike panicle. Species about
12; in the Tropics of both hemi-
spheres, 1 extending into the south-
eastern United States.
Type species: Panicum gibbum Ell.
Sacciolepis Nash, in Britton, Man. 80.
1901. Only one species is described.
Sacciolepis striata (L.) Nash
(Holcus striatm L., Panicum. gib-
bum Ell.) (fig. 144) is a stolonifer-
ous marsh grass found from Vir-
ginia to Oklahoma and southward.
It has no economic value.
121. OPLISMENUS Beauv.
Spikelets terete or somewhat lat-
erally compressed, subsessile, soli-
tary or in pairs, in two rows
crowded or approximate on
one side of a narrow scabrous
or hairy rachis; glumes
about equal, emarginate or
2-lobed, awned from between
the lobes; sterile lemma ex-
ceeding the glumes and fruit,
notched or entire, mucronate
FIG. 144. Sacciolepis striata. Plant, X J ; two views of spikelet and fertile floret,
X 10.
or short-awned, inclosing a hyaline palea ; fertile lemma elliptic, acute,
convex or boat shaped, the firm margins clasping the palea, not inrolled.
238 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Freely branching, creeping, shade-loving annuals or perennials,
with erect flowering shoots, flat, thin lanceolate or ovate blades, and
several one-sided, thickish, short spikes rather distant on a main axis.
Species about 10, in the Tropics of both hemispheres, 1 extending
into the Southern States.
Type species: Oplismenus africanus Beauv.
Oplismenus Beauv., Fl. Owar. 2: 14, pi. 58, f. 1. 1809. A single species is
described.
Orthopogon R. Br., Prodr. Nov. Holl. 194. 1810. Four species are described,
O. compositus, O. aemulus, O. flaccidus, and O. imbecillis. Panicum compositum
L. is chosen as the type, this being the basis of the first species of Orthopogon.
The only species in the United States is Oplismenus setarius
(Lam.) Roem. and Schult. (fig. 145), found in shady places from
Florida to Texas. This is grazed by stock, but is not sufficiently
abundant to be of importance.
122. ECHINOCHLOA Beauv.
Spikelets plano-convex, often stiffly hispid, subsessile, solitary or
in irregular clusters on one side of the panicle branches; first glume
about half the length of the spikelet, pointed ; second glume and sterile
lemma equal, pointed, mucronate, or the glume short-awned and the
lemma long-awned, sometimes conspicuously so, inclosing a mem-
branaceous palea and sometimes a staminate flower; fertile lemma
plano-convex, smooth and shining, acuminate-pointed, the margins
inrolled below, flat above, the apex of the palea not inclosed.
Coarse, often succulent, annual, or sometimes perennial, grasses,
with compressed sheaths, linear flat blades, and rather compact pani-
cles composed of short, densely flowered racemes along a main axis.
Species about 10, in the warm and temperate regions of both hemi-
spheres ; 4 species in the United States.
Type species : Panicum crusgalli L.
Echinochloa Beauv., Ess. Agrost. 53, pi. 11, f. 2. 1812. The species figured is
selected as the type.
With the exception of E chmochloa colonum (L.) Link, the species
of Echinochloa have distinctly awned or awn-pointed spikelets. In
that cosmopolitan species the spikelets are merely apiculate or mucro-
nate, and the racemes are simple and rather remote.
Echinochloa CTUsgdlli (L.) Beauv. (fig. 146), barnyard grass, is
a common weedy annual found throughout the country except at
higher altitudes. The panicles vary much in the size and length of
the awns, and in color vary from green to dark purple. In fields and
waste places the plants are usually spreading, but in water or wet
places may be stout and erect. An erect short-awned form, with
short, ascending racemes, found in the Southwestern States, is the
Mexican E. crusgalli zelayensis (H. B. K.) Hitchc. (Oplismenus
zelayensis H. B. K.). E. crusgalli edulis (Panicum frumentaceum
Koxb., 1820, not Salisb., 1796) is a form that has been cultivated in
GENERA OF GRASSES OF THE UNITED STATES. 'Jo 9
tropical Asia for the seeds, which are used for food. It differs in
having short, compact, appressed, somewhat incurved racemes and
nearly awnless spikelets. This form has been advertised by seeds-
FIG. 145. Oplismenus setarius. Plant, X J ; two views of spikelet and fertile floret,
X 10.
men in this country as billion-dollar grass and recommended for
forage. It has some forage value, but requires considerable moisture
to produce abundantly, and is rather too succulent to make good hay.
240 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
In these forms the sheaths are smooth. Echinochloa walteri (Pursh)
Heller is a closely allied native species with hirsute sheaths and long-
awned spikelets.
All the species of Echinochloa are
grazed by horses and cattle, but
usually grow in situations where they
can not well be utilized.
FIG. 146. Barnyard grass, Echinochloa crusgalll. Plant,
and fertile floret, X 10.
two views of spikelet
GENERA OF GRASSES OF THE UNITED STATES. 241
123. TRICHOLAENA Schrad.
Spikelets on short capillary pedicels; first glume small, much
shorter than the spikelet, villous; second glume and sterile lemma
equal, raised on a stipe above the first glume, emarginate or slightly
lobed, short-awned, covered, except toward the apex, with long silky
hairs, the palea of the sterile lemma well developed ; fertile lemma
shorter than the spikelet, cartilaginous, smooth, boat shaped, obtuse,
the margins thin, not inrolled, inclosing the margins of the palea.
Perennial or annual grasses, with rather open panicles of silky
spikelets. Species about 15, in the Eastern Hemisphere, mostly in
Africa, one cultivated in the United States.
Type species: Tricholaena micrantha Schrad.
Tricholaena Schrad.; Schult, Mant. 2: 163. 1824. Three species are de-
scribed, but the second and third are included in the genus with a question.
The first species is taken as the type.
Tricholaena rosea Nees (fig. 147), Natal grass, is becoming an
important forage grass in the sandy lands of Florida, where it has
been recently introduced. It is an upright, rather slender perennial,
2 to 4 feet tall, with beautiful purple panicles, 4 to 10 inches long.
The color varies from. light purple or pink to wine color. Although
a perennial, it is usually cultivated as an annual, as it will not survive
temperatures below freezing.
124. CHAETOCHLOA Scribn.
(Setaria Beauv.)
Spikelets subtended by one to several bristles (sterile branchlets),
falling free from the bristles, awnless; first glume broad, usually
less than half the length of the spikelet, 3 to 5 nerved ; second glume
and sterile lemma equal, or the former shorter, several-nerved; fer-
tile lemma coriaceous indurate, smooth or rugose.
Annual or perennial grasses, with narrow terminal panicles, these
dense and spikelike or somewhat loose and open. Species about 65,
in the tropical and warm temperate regions of both hemispheres; 18
species in the United States.
Type species: Panicum viridc L.
Setaria Beauv., Ess. Agrost. 51, pi. 13, f. 3, 1812, not Acharius, 1789, nor
Michaux, 1803. Fourteen species are listed, 8. viridis being illustrated. Pani-
cum viride L., on which this species is based, is taken as the type.
Chaetochloa Scribn., U. S. Dept. Agr., Div. Agrost. Bull. 4 : 38. 1897. Scribner
proposes the name Chaetochloa for Setaria Beauv., stating that the name Setaria
was first used by Beauvois (Fl. Owar. 1809) 1 for a species of Pennisetum.
Scribner himself applies the name Chaetochloa to the species allied to Panicum
viride. Hence it seems that he wished to substitute Chaetochloa for Setaria
as used by Beauvois in his Essai (Ess. Agrost. 51, pi. 13, f. 3, 1812). The figured
species, Setaria viridis (L.) Beauv., becomes the type.
The name Ixophorus Schlecht. was applied to this genus by Nash, 2 but that
is based on a Mexican species not congeneric with ours.
1 According to Dr. J. H. Barnhart the part containing Setaria (PI. Owar. 2: 80) was
not published until 1818.
2 Britton and Brown, Illustr. Fl. 1 : 125. 1896.
97769 19 Bull. 772 16
242 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 147. Natal grass, TricJiolaena rosea. Plant, X i ; spikelet and fertile floret, X iO.
GENERA OF GRASSES OF THE UNITED STATES. 243
lU'al 1 applied the name Chamaeraphis It. Br. to American species of Chae-
tochloa, but that is 5111 Auslnilian gomis in which the articulation is below the
spikelet-bearing branches, as in Peimisetum.
One group of this genus, section Ptychophyllum, has broad, often
plaited, blades and loose or open panicles, the bristles solitary and
at the base of only the uppermost spikelets on the short branchlets.
This section has usually been referred to Panicum, but shows a closer
relationship to Chaetochloa. Two species of this group, both per-
ennials, are cultivated in greenhouses or in the open in the Tropics
for ornament, chiefly on account of the broad plaited blades that
resemble those of young palms. C Jiaetochloa sulcata (Aubl.) Hitchc.
(Panic win sulcatuui Aubl.) has narrow, rather dense panicles, 1 to 2
feet long, and blades about 2 inches wide. Chaetochloa palmifolium
(Willd.) Hitchc. and Chase has large open panicles and broader
blades. This has been known in cultivation as Panicwm plicatum^
but is not P. plicatwm, Lam. It is sometimes called palm-grass.
Of the species of Chaetochloa proper 2 (Setaria Beauv.) several
are weeds in cultivated soil. Two annual species are common in the
eastern United States, where they are known as foxtail or pigeon
grass. Chaetochloa mridis (L.) Scribn., green foxtail, has a green,
somewhat pointed head, with untwisted blades. Chaetochloa lutes-
cens (Weigel) Stuntz (Setaria glauca of most authors, not Panicum
glaucuni L.) (fig. 148), yellow foxtail, has cylindric yellow obtuse
heads and blades twisted in a half spiral so that toward the end the
upper surface is beneath.
Another annual species common in waste ^places is Chaetochloa
verticillata (L.) Scribn., in which the bristles are backwardly rough-
ened, the heads thus sticking readily to clothing. Chaetochloa geni-
culata (Lam.) Millsp. and Chase is a perennial species resembling
yellow foxtail. This is common in the Southern States and through-
out the Tropics. Chaetochloa magna (Griseb.) Scribn., a robust
annual as much as 9 feet high, with a dense panicle or head as much
as a foot long and 2 inches in diameter, is found in marshes from
Maryland to the West Indies.
Chaetochloa macrostachya (H. B. K.) Scribn. and Merr. (here-
tofore commonly confused with the South American C. composita
(H. B. K.) Scribn.), is of some importance as a range grass from
Texas to Arizona. It is a pale perennial, with somewhat pointed
spikelike panicles. The two annuals, C. viridis and C. lutescens, are
often sufficiently abundant to furnish considerable forage.
The most important species of the genus is Chaetochloa italica (L.)
Scribn. (Setaria italica Beauv.). This is called millet, or, to dis-
tinguish it from other kinds of millet, foxtail millet. Millet is an
1 Grasses N. Amer. 2: 150. 1896.
2 The genus was revised by Scribner and Merrill, U. S. Dept. Agr., Div. Agrost. Bull.
21. 1900.
244 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
erect annual, 2 to 4 feet tall, with a dense, bristly, yel-
low or purple head. There are many varieties in culti-
vation, differing in the size and lobing of the head, the
length and color of the bristles, and the color of the
seed. Small forms resemble C. viridis, but may be dis-
tinguished by the articulation of the seed. In C. viridis
the seed (fruit, that is, the fertile floret) falls from the
pedicel inclosed within the glumes. In C. italica the
seed readily separates from the
glumes b} T an articulation above
the sterile lemma. A ripe head
of C. italica rubbed between the
palms yields free seed. A head
of C. viridis will yield entire
spikelets.
FIG. 148. Yellow foxtail, Chaetochloa lutesccns. Plant, X I; two views of spikelet
and fertile floret, X 10.
The varieties of Chaetochloa italica cultivated in the United States
have been classified as follows 1 (under Setaria italica) :
Fruit dark colored (reddish or orange to blackish or brownish black).
Fruit reddish or orange rubrofructa.
Fruit blackish, brownish black, or purplish black with pale yellowish
straw lines intermingled, these sometimes predomina.ting_?u'firro/Twcto.
1 See Hubbard, Amer. Journ. Bot 2 : 187. 1915.
GENERA OF GRASSES OF THE UNITED STATES. 245
Fruit pale (yellowish to straw or light brown).
Bristles green.
Panicle more or less open-lobulate stramineofructa.
Panicle dense or slightly lobulate at base germanica.
Bristles brown or purple.
Bristles brown brunneoseta.
Bristles purple.
Panicle more or less lobulate hostii.
Panicle dense or slightly lobulate at base metzgeri.
Subsp. ntbrnfructa Hubb. : The only forms cultivated in the United States
are var. pitrpiircoscta Ilubb., Turkish millet, with purple bristles and a large
lobulate head; and subvar. violacea (Alef.) Hubb., Kursk millet or Siberian
millet, with purple bristles and a smaller dense head.
Subsp. niyrofructa Hubb. : The common form cultivated in the United States
is var. atra, or Hungarian grass. This has small dense heads 1 to 3 inches long
with purple bristles.
Subsp. stramineofructa Hubb., German millet: Plants robust with heads 4
to 12 inches long and as much as 2 inches wide, the bristles noticeably longer
than tbo spikolots. Forma breviseta (Doell) Hubb., Golden Wonder millet,
differs in having bristles shorter than the spikelets or barely exceeding them.
Subsp. germanica (Mill.) Hubb., common millet: Heads mostly 2 to 3 inches
long, one-fourth to one-half an inch thick, the bristles noticeably longer than
the spikelets; forma mitis (Alef.) Hubb. with bristles shorter than the spike-
lets or barely exceeding them. There has been an unfortunate misapplication
of the name German millet. The forms cultivated under this name are not
the subspecies germanica as one would suppose (see the preceding subspecies).
Var. bfunneoseta Hubb., Aino millet : Head large, lobulate, brown. Subvar.
densior Hubb. has a compact scarcely lobulate head.
Var. hostii Hubb., German millet : Head large, lobulate, purple ; differs from
the other form of German millet (subsp. stramineofructa) in having purple
bristles.
Var. metzgeri (Kornicke) Hubb., common millet: Bristles noticeably longer
than the spikelets; differs from the other form of common millet (subsp. ger-
manica'] in having purple bristles; sometimes called Hungarian grass, a name
which should be applied to subsp. nigrofructa.
125. PENNISETUM Rich.
Spikelets solitary or in groups of two or three, surrounded by an
involucre of bristles, these not united except at the very base, often
plumose, falling attached to the spikelets; first glume shorter than
the spikelet, sometimes minute or wanting; second glume shorter
than or equaling the sterile lemma; fertile lemma chartaceous,
smooth, the margin thin, inclosing the palea.
Annual or perennial, often branched grasses, with usually flat
blades and dense spikelike panicles. Species about 50, in the tropical
regions of both hemispheres ; 1 species in southern Florida.
Type species: Pennisetnm typhoideum Rich.
Penniseturn Rich., in Pers. Syn. PI. 1 : 72. 1805. Five species are described,
1\ typhoideum, P. setosum, P. cenehroides, P. orientale, and P. molaceum.
Pennisetum typhoideum, being a well-known economic species, is chosen as the
type.
246 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Penicillaria Willd., Enum. PL 2: 1036. 1809. A single species, p. spicatus,
based on Holcus sjncatus L., is described.
Gymnothrix Beauv., Ess. Agrost. 59, pi. 13. f. 6. 1812. The type species is
G. thourii, the one figured. Beauvois distinguished Gymnothrix from Pen-
niseturn by the glabrous (not plumose) bristles.
The most important species of the genus is Pennisetum
glaucum (L.) R. Br. (P. typkoideumRich., P. ameri-
canum (L.) Schum., Penicillaria spicata (L.) Willd.),
called in this country pearl millet (fig. 149). This is a
robust annual, 4 to 8 feet tall, with broad blades like
those of corn or sorghum, and a dense, erect, cylindric
spikelike panicle as much as a foot long, the stem woolly
below the spike, the involucre containing usually two
spikelets about as long as the bristles. Pearl millet dif-
fers from the other Paniceae in having an enlarged cary-
opsis bursting through its lemma and palea. The cary-
opsis, or "seed," is deciduous by an articulation above
the fertile lemma, the bristles and the floral bracts re-
maining on the spike. Pearl millet is widely cultivated
in tropical Africa and Asia, the seed being used for hu-
man food. The species has been cultivated since pre-
FIG. 149. Pearl millet, Pennisetum glaucum. Inflorescence, X \ ', two views of spikelet
and caryopsis, X 10.
historic times, its wild prototype being unknown. In the United
States pearl millet is used to a limited extent in the Southern States
for forage, especially for soiling.
GENERA OF GRASSES OF THE UNITED STATES. 247
Panicum glaucum L. (Sp. PI. 56. 1753), on which was based Pen-
nisetum glaucum, was itself based on a citation from the Flora Zey-
lanica (Panicum spica te^eti, involucris bifloris fasciculato-pilosis L.
Fl. Zeyl. 18. 1747), which refers to the species afterwards described
as Pennisetum typhoideum. Linnaeus described two varieties of
Panicum glauwm, these being now called Chaetochloa viridis and C.
lutescens. Through an error the name Panicum glaucum has been
applied by nearly all botanists to the latter species. When the
species was transferred to Setaria and to Chaetochloa the error was
perpetuated. Robert Brown transferred Panicum glaucum to Pen-
nisetum but used the name in the erroneous sense, as is shown by his
description. Nevertheless, Robert Brown must be credited with the
name Pennisetum glaucum even though he described the wrong
species. The only species of Pennisetum found native in the United
States is P. setosum (Swartz) Rich. (fig. 150), of tropical America,
which extends into southern Florida. Two species are cultivated
for ornament. * Pennisetum villosum R. Br. (P. longistylum of flor-
ists, not Hochst.) is a slender perennial 1 or 2 feet tall with a pale
feathery head 2 to 4 inches long, the bristles 1 to 2 inches long.
Pennisetum ruppelii Steud., fountain grass, with beautiful pink or
purple nodding spikes, longer and more graceful than those of the
preceding, is used for borders. An African species, Napier grass
(P. purpureum Schum.), has been tested recently in the Southern
States as a forage plant. It is a coarse perennial 8 to 12 feet tall.
126. CENCHETJS L.
Spikelets solitary or few together, surrounded and inclosed by a
spiny bur composed of numerous coalescing bristles (sterile branch-
lets), the bur globular, the peduncle short and thick, articulate at
base, falling with the spikelets and permanently inclosing them, the
seed germinating within the old involucre, the spines usually
retrorsely barbed.
Annual or sometimes perennial, commonly low branching grasses,
with flat blades and racemes of burs, the burs readily deciduous.
Species about 25, in the warmer parts of both hemispheres, but chiefly
in America; 7 species in the United States, chiefly in the south-
ern portion.
Type species: Cenchrus echinatus L.
Cenchrus L., Sp. PI. 1049, 1753 ; Gen. PI., ed. 5, 471. 1754. Linnaeus describes
five species, C. racemosus, C. capitatus, C. echinatus, C. tribuloides, and C. fru-
tescens. The reference in the Genera Plantarum is to Panicastrella Mich. 31, that
is, to plate 31 of Micheli's Nova Plantarum Genera, published in 1729. The ac-
count of the genus Panicastrella is on page 36. The two species here described
are cited as synonyms by Linnaeus, under Cenchrus echinatus and C. tribuloides,
both being based on descriptions in Sloane's History of Jamaica. The first
species, C. echinatus, is chosen as the type. Cenchrus racemosus is now referred
to Nazia ; C. capitatus to Echinaria. Cenchrus frutescens, of which there is no
specimen in the Linnaean Herbarium, is uncertain. It is stated to come from
America, but this is a misprint for Armenia, as is shown by the second edition of
the Species Plantarum,
248 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 150. Pennisetum setosum. Plant, X 1 ; two views of spikelet and fertile floret,
X 10.
GENERA OF GRASSES OF THE UNITED STATES. 249
Rarum Adans., Fain. PI. 2: 35, 597. 1763. Of the four pre-Linnsean citations
two are given by Linntmis under Ccnclirux echinatus, which is taken as the type.
Cenchropsis Nash, in Small, Fl. Southeast. U. S. 109. 1903. Cenchrus myosu-
roides H. B. K. is designated as the type.
Nastus Lunell, Amer. Midi. Nat. 4: 214. 1915. The name is ascribed to
Dioscorides and " Cenchrus frutescens Linn." given as the type. Lunell intends
in apply the name to Cenchrus, but the designated type is unidentifiable and
certainly is not a grass.
Most of the species of the United States are annual. Cenchrus
myosuroides H. B. K. differs from our other species in the involucre,
or bur, with bristles united only at the base. Were it not for certain
species of Australasia which are intermediate, this species might be
segregated under a distinct genus, as was done by Nash. 1 The original
C. tribuloides L. (fig. 151) is a dune grass of the Atlantic coast, with
large villous burs. The common sand bur of the interior found in
sandy fields across the continent is C. pauciflorus Benth. This was
formerly confused with C. tribuloides and more recently has been
called C. carolinianus Walt., which proves to be a different species.
Cenchrus echinatus, a common tropical species extending into the
Southern States, has a less prickly bur, with a ring of slender bristles
at the base of the stout prickles. The species of Cenchrus, especially
the last two, are excellent forage grasses before the burs are formed.
The genus has been revised by Nash. 2
127. AMPHICARPON Raf.
Spikelets of two kinds on the same plant, one in a terminal panicle,
perfect but not fruitful, the other cleistogamous on slender leafless
subterranean branches from the base of the culm or sometimes also
from the lower nodes; first glume of the aerial spikelets variable
in size, sometimes obsolete; second glume and sterile lemma about
equal; lemma and palea indurate, the margins of the lemma thin
and flat; fruiting spikelets much larger, the first glume wanting;
second glume and sterile lemma strongly nerved, subrigid, exceeded
at maturity by the turgid, elliptic, acuminate fruit with strongly
indurate lemma and palea, the margins of the lemma thin and flat;
stamens with small anthers on short filaments.
Annual or perennial erect grasses, with flat blades and narrow
terminal panicles. Species two, in the Atlantic Coastal Plain region
of the United States.
Type species: Milium ampMcarpum Pursh.
Amphicarpon Raf., Amer. Month. Mag. 2 : 175. 1818. In a review of Pursh's-
Flora of North America, Rafmesque indicates that Milium amphicarpon should
be a new genus, Amphicarpon Raf. Kunth 8 published the genus Amphicarpum,
based on the same type, apparently ignorant of Rafinesque's proposed name.
1 Censhropsis myosuroldcs (H. B. K.) Nash, in Small, Fl. Southeast, U. S. 109. 1903.
2 Bull. Torrey Club 22: 298-301. 1895.
3 Rev. Gram. 1: 28. 1829.
250 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
The two species are AmpMcarpon purshii Kunth (A. amphicarpon
(Pursh) Nash), an annual (fig. 152), with hirsute blades, found
FIG. 151. Cenchrus tribuloides. Plant, X \ ; two views of spikelet and fertile floret,
X 10.
from New Jersey to Florida, and A. florid anum Chapm., a stolonif-
erous perennial, with glabrous blades, confined to Florida. The
latter often provides abundant pasture.
GENERA OF GRASSES OF THE UNITED STATES.
251
FIG. 152. Amphicarpon purshu. Plant, X I ; two views of aerial spikelet and floret
and the subterranean spikelet and fertile floret, X 10.
252 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Olyra L., Syst. Nat., ed. 10, 2: 1261. 1T59. A tropical American
genus, one species of which, 0. latifolia- L. (fig. 153) is credited
to Florida by Small in his Flora of the Southeastern United States.
The record is doubtful.
A glabrous perennial, bamboolike in aspect, as much as 15 feet
tall, the branches straggling over shrubs; blades petiolate, asym-
metrically lanceolate-oblong, as much as 8 inches long and 2 inches
wide; panicles 4 to 6 inches long, the branches stiffly ascending or
spreading, each bearing a single, large, long-acuminate, pistillate
spikelet at the thickened summit and several small slender-pediceled
staminate spikelets along the branch.
13. ANDROPOGONEAE, THE SORGHUM TRIBE.
128. IMPERATA Cyrillo.
Spikelets all alike, awnless, in pairs, unequally pedicellate on a
slender continuous rachis, surrounded by long silky hairs; glumes
about equal, membranaceous ; sterile lemma, fertile lemma, and palea
thin and hyaline.
Perennial, slender, erect grasses, with terminal narrow woolly pani-
cles. Species seven, in the tropical regions of both hemispheres ; two
species in the United States, three others in tropical America.
Type species : Lagnrus cyUndrieus L.
Imperata Cyrillo, PI. Rar. Neap. 2: 26. 1792. A single species is described,
/. arundinacea Cyrillo, but the genus is based upon Lagurus cylindricus L. 1
Our species are Imperata l>rasUiensis Trin., in southern Florida,
and /. hookcri Rupr. (fig. 154), from western Texas to southern
California. They are not found in sufficient abundance to be of
agricultural value.
129. MISCANTHTJS Anderss.
Spikelets all alike, in pairs unequally pedicellate along a slender
continuous rachis ; glumes equal, membranaceous or somewhat coria-
ceous; sterile lemma a little shorter than the glumes, hyaline; fertile
lemma hyaline, smaller than the sterile lemma, extending into a deli-
cate bent and flexuous awn ; palea small and hyaline.
Robust perennials, with, long flat blades and terminal panicles of
aggregate spreading slender racemes, our species with a tuft of
silky hairs at the base of the spikelet, surrounding it and of about
the same length as the glumes, the palea of the short-pedicellate spike-
let about one-fourth as long as the lemma, the palea of the long-
pedicellate spikelet obsolete. Species about eight, in southeastern
Asia and South Africa ; one cultivated in the United States.
1 Cyrillo gives the generic heading thus : " Imperata. Lagurus cylindricus Linn., Sp.
PI. 120, n. 2."
GENEEA OF GRASSES OF THE UNITED STATES. 253
FIG. 153. Olyra latifolia. Plant, X I ; pistillate spikelet, fertile floret, and staminate
spikelet, X 5,
254 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Type species: Mixcantlinx jnpoiiirn* Anderss.
Miscanthus Anderss., Ofv. Svensk. Vet. Akad. Forh. 1855: 165. 1856. Anders-
son describes five species, M. capenms, M.-japoni-cus, J/. luzonensis, M. sinensis,
and M. purpurascens. Andersson states that M. capensis is a transition from
n
FIG. 154. Imperata hookeri. Plant, X 1 ; spikelet, X 5.
this group to the other genera of the tribe ; hence this species may be excluded
from consideration in selecting the type of the genus. The second species, M.
japonicus, is therefore selected as the type.
GENERA OF GRASSES OF THE UNITED STATES. 255
Xiphagrostis Coville, Contr. U. S. Nat. Herb. 9: 399, pi. 69. 1905. Two
spec'ies are included, X. floridula (Labill.) Coville and X. japonica (Thunb.)
Coville. Saccharum floridulum Labill., on which the first species is based, is
designated as the type. Coville assumed M. capensis to be the type of Miscan-
thus, as it was the first species described (see Miscanthus, p. 254), and referred
Mi Acanthus sinensis and its allies, which were not congeneric with M. capensis,
to Xiphagrostis.
Miscanthus sinensis Anderss. (PI. XVIII; fig. 155) is cultivated in
the United States as an ornamental. Commercially it is known as
Eulalia japonica or merely eulalia. This is a reedy grass 4 to 8 feet
high, growing in large bunches, with flat mostly basal blades, 2 to 3
feet long and about half an inch wide, gradually narrowed to a
slender point, the panicle somewhat fan shaped, consisting of nu-
merous silky racemes 4 to 8 inches long, aggregate at the summit of
the culm. Eulalia has escaped from cultivation and is found grow-
ing wild in some localities. There are two varieties of Miscanthus
sinensis with variegated leaves, var. variegatus Beal, with striped
blades, and var. zebrinus Beal, with banded blades. Miscanthus
sinensis gracillimus is a variety with very narrow blades. Another
species, M. nepalensis (Trin.) Hack., is occasionally cultivated under
the name of Himalaya fairy grass. This has spikelets about one-
fourth as long as the hairs at their base.
130. SACCHARTJM L.
Spikelets in pairs, one sessile, the other pedicellate, both perfect,
awnless, arranged in panicled racemes, the axis disarticulating below
the spikelets; glumes somewhat indurate, sterile lemma similar but
hyaline ; fertile lemma hyaline, sometimes wanting.
Perennial grasses of tropical regions, including about 10 species.
Type species : Saccharum offldnarum L.
Saccharum L., Sp. PI. 54, 1753 ; Gen. PL, ed. 5, 28. 1754. Two species are de-
scribed. The first is chosen as the type, because it is a well-known economic
species. The second species, S. spicatum, is now referred to the genus Imperata.
Saccharum officmarwn (fig. 156), the sugar cane, is cultivated in
Louisiana and to a limited degree in some of the other Gulf States.
It is a tall stout grass, 8 to 15 feet tall or even taller, with solid juicy
stems, broad flat blades, and large plumelike panicles 1 to 2 feet
long, with numerous small spikelets about 3 mm. long, each sur-
rounded at the base by a tuft of silky hairs two or three times as
long as the spikelet. The glumes and the delicate sterile lemma are
about the same length, the fertile lemma and palea being absent.
Sugar cane is cultivated chiefly for the production of sugar and
molasses; but, especially in the Gulf States outside of Louisiana, it is
also used for forage.
131. ERIANTHUS Michx.
Spikelets all alike, in pairs along a slender axis, one sessile, the other
pedicellate, the rachis disarticulating below the spikelets, the rachis
256 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 155. Eulalia, MiscantHus sinensis. Sketch of several stems, much reduced ; branch
of panicle, X | ; spikelet, X 5,
GENERA OF GRASSES OF THE UNITED STATES.
257
FIG. 156. Sugar cane, Saccharum offlcinarum. Sketch of three stems, much reduced;
a few branches of panicle, X \ ', spikelet with pedicel of second spikelet (the shorter)
. and joint of rachis, X 5.
97769 19 Bull. 772 17
258 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
joint and pedicel falling attached to the sessile spikelet; glumes
coriaceous, equal, usually -copiously clothed, at least at the base, with
long silky spreading hairs; sterile lemma thin and hyaline; fertile
lemma hyaline, the midnerve extending into a slender awn; palea
small and hyaline.
Perennial reedlike grasses, with flat blades and terminal oblong,
usually dense silky panicles. Species about 20, in the warmer regions
of both hemispheres ; five in the United States, mostly in the Atlantic
Coastal Plain.
Type species : Erianthus saccJiaroides Michx.
Erianthus Michx., Fl. Bor. Amer. 1 : 54. 1803. Michaux describes two species,
E. saccJiaroides and E. brevibarbis. He derives the name of the genus from
two Greek words which mean hairy flower, because of the very densely villous
involucre below the spikelets, and he remarks that the genus is closely allied
to Saccharum. The first species, with long involucral hairs, he names
sacchar aides, and the second, with short hairs, brevibarbis. The first species,
better representing Michaux's idea of the genus, is chosen as the type.
The commonest native species is Erianthus saccJiaroides (fig. 157) ,
with straight awns and woolly panicles. Erianthus divaricatus (L.)
Hitchc., with pale panicles, and E. contortus Baldw., with dark
panicles, have flat, .twisted awns. Erianthm strictus Baldw. has
naked spikelets, and E. 'brevibarbis Michx. has short hairs at the base
of the spikelets. The plants are too coarse to be of value for grazing,
but some of our native species might well be cultivated for ornament.
One species, E. ravennae (L.) Beauv., a native of the Mediterranean
region, is occasionally cultivated for ornament because of the silky
plumes. It is called Ravenna grass and also by the less distinctive
names, plume-grass and hardy pampas grass. The culms are several
feet high, growing in large clumps, with blades about half an inch
wide, tapering into a long slender point, the plume being as much as
2 feet long.
132. ANDROPOGON L.
Spikelets in pairs at each node of an articulate rachis, one sessile
and perfect, the other pedicellate and either staminate, neuter, or re-
duced to the pedicel, the rachis and the pedicels of the sterile spikelets
often villous, sometimes conspicuously so ; glumes of the fertile spike-
let coriaceous, narrow, awnless, the first rounded, flat, or concave on
the back, several-nerved, the median nerve weak or wanting; sterile
lemma shorter than the glumes, empty, hyaline; fertile lemma
hyaline, narrow, entire or bifid, usually bearing a bent and twisted
awn from the apex or from between the lobes; palea hyaline, small
or wanting; pedicellate spikelet awnless, sometimes staminate and
about as large as the sessile spikelet, sometimes consisting of one or
more reduced glumes, sometimes wanting, only the pedicel present.
Rather coarse perennials (in the United States), with solid culms,
the spikelets arranged in racemes, these numerous, aggregate on an
GENERA OF GRASSES OF THE UNITED STATES. 259
FIG. 157. Plume-grass, Erianthus saccharoides. Plant, X \. ; spikelet with pedicel (at
right) and joint of rachis, X 5.
260 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
exserted peduncle, or single, in pairs, or sometimes in threes or fours,
the common peduncle usually inclosed by a spathelike sheath, these
sheaths often numerous, forming a compound inflorescence, usually
narrow, but sometimes in dense subcorymbose masses. Species about
150, in all warmer parts of the world ; about 30 species in the United
States, mostly in the South.
Type species Andropogon -rirginicus L.
Andropogon L., Sp. PI 1045, 1753 ; Gen. P1 M ed. 5, 468. 1754. Linnreus de-
scribes 12 species. The reference in the Genera Plantarum is to " Roy. Ingdb.
52." In this work, Flora Leydensis, published in 1740, Royen describes two
species, the first of these is later (Species Plantarum) named Andropogon lilrtum
by Linnaeus, and the second A. virgin icu in. The type should be chosen from these
two. The two species appear to be equally familiar to Royen and to Linnaeus,
though A. rirginicus is more fully described and has priority of position in
the Species Plantarum. Andropogon rir<iinicns is chosen as the type, as this
choice retains the generic name for its usual signification. Of the 12 species
originally described, 4 are retained in Andropogon, A. d-istaclu/os, A. vir-
ginicus, A. bicornis, and A. ischaemum. Andropogon contortus is now referred to
Heteropogon, A. divaricatus to Erianthus, A. nutans to Sorghastrum, A. alope-
curoides to Erianthus, A. scfioenantlms, A. liirtus, and A. nardus to Cymbopo-
gon. Andropogon fasciculatus, the last species, is unidentifiable.
Schizachyrium Nees, Agrost. Bras. 331. 1829. The type species is Andro-
pogon condensatus H. B. K., upon which is based 8. condensatnm, first of the six
species described. Nees states, in a paragraph at the end of the generic descrip-
tion, that besides the species he enumerates Andropogon brevifolms belongs to
Schizachyrium. Because of this statement Nash 1 chooses the latter species
as the type. This group includes the species of Andropogon with racemes
single at the ends of the branches.
Dimeiostemon Raf., Bull. Bot. Seringe 1 : 221. 1830. "Andropogon vaginatus
Ell., A. sessiliflorus [nomen nudurn], A. macrurus, A. vaginatus [repeated], A.
tetrastachys" are listed. Andropogon vaginatus Ell., which is the same as
A. virginicus L., is taken as the type.
Amphilophis Nash, in Britton, Man. 71. 1901. Only one species described, An-
dropogon torreyanus Steud. This group includes the species of Andropogon
with numerous racemes in a naked panicle. Amphilophis was first used by
Trinius 2 as a section of Andropogon.
Our species are divided into three groups: One (constituting the
genus Schizachyrium of some authors) Avith the racemes single on
each peduncle ; two, with the racemes in pairs, or sometimes in threes
or fours, on each peduncle ; three, with the racemes aggregate toward
the naked summit of the culms and branches. The commonest repre-
sentative in the United States of the first group is Andropogon scopa-
rius Michx. (fig. 158). This is an erect bunch-grass 2 to 4 feet high,
the racemes scattered along the upper part of the stem. It is common
throughout the eastern half of the United States. It is a fairly good
forage grass and forms a part of the wild prairie hay in the eastern
portion of the Great Plains, where it is called little bluestem. The sec-
ond group is represented by numerous species in the Southern States.
One of these, A. virginicus L. (fig. 159) is found in old fields, open
woods, and sterile ground from Massachusetts to Texas and Florida.
This is called broom sedge, though the name is also applied to some
of the other species of Andropogon. Andropogon virginicus is a
iN. Amer. Fl. 17: 100. 1912.
2 M5m. Acad. St. Petersb. VI. 2: 285. 1832.
GENERA OF GRASSES OF THE "UNITED STATES.
261
bunch-grass with tall slender culms, the feathery racemes- in pairs,
the rachis flexuous, the short common* peduncle and usually the lower
part of the racemes inclosed in the inflated sheathing bract,
FIG. 158. Little biucstem, Andropogon scopa-
rius. riant, X I ; pair of spikelets with
joint of rachis (at left), X 5.
these bracts scattered
along the culm on short
branches. An allied spe-
cies, A. elliottii Chapm.,
found in the Southeast-
ern States, is distin-
guished by the conspicu-
ously inflated upper
foliage sheaths, the blade
being often reduced to an
appendage. Another im-
portant species, belong-
ing to this group but dif-
fering in aspect from the
262 BULLETIN 772, U. S; DEPARTMENT OF AGRICULTURE.
FIG. 159. Broom sedge, Andropogon virgin icits. Plant X I ; pair of spikelets with
joint of rachis (at left), the second spikelet obsolete, the hairy pedicel only present,
X 5.
GENERA OF GRASSES OF THE UNITED STATES. 263
last, is A. fut-catus Muhl. (PL XIX; fig. 1GO). This grows through-
out the eastern half of the United States and is an important forage
grass in the western portion of its range. Here it is the chief con-
stituent of prairie hay and is known as big bluestem. It is a
tall, usually purplish bunch-grass, the racemes only slightly hairy,
borne in twos to fours at the ends of the culms and the short
branches, the rachis strict. In the Great Plains, grasses are popu-
larly divided into tall grasses and short grasses. The former, of
which A. furcatus is the most important, are found chiefly in the
valleys and draws; the latter, including buffalo grass and grama
grass, are found on the uplands. The third group of Andropogon
is represented in this country by only three species, all extending
northward from Mexico into the Southwestern States. The very
hairy or feathery racemes are crowded in an oblong or somewhat
flabellate white panicle terminating the main culm and its branches.
One of these, J.. saccharoides Swartz (fig. 161) (A. argenteus DC.,
-L-1. "barblnodis Lag.), is distinguished by the bearded nodes. Andro-
pogon saccharoides laguroides (DC.) Hack. (A. torreyanus Steud.),
with more slender culms and smooth nodes, is found as far north as
Kansas. Another species of the group, A. perforatus Trin., of
Moxioo, rare in this country, differs in having a little pinhole or. pit
in the first glume.
An allied group of grasses is of importance in tropical parts of
the Old World because of the essential oils obtained from them.
They are included in Andropogon by some authors, but are referred
by others to Cymbopogon. A full account of these grasses is given
by Stapf. 1 The most important are citronella grass (Andropogon
nardus L. ; Cymbopogon nardus Rendle) and lemon grass (Andro-
pogon citratus DC., Cymbopogon citratus Stapf). These are robust
grasses with large compound inflorescences, the small racemes in
pairs, each pair partly included in a sheathing spathe.
An allied genus, Anatherum Beauv., is represented by a single
species, A. zizanioides (L.) Hitchc. and Chase (Andropogon muri-
catus Eetz. ; Vetiveria zizanioides Nash). This Old World grass is
frequently cultivated in tropical America for hedges and for the
aromatic roots, which are used for making screens and mats to per-
fume the air of houses. These roots readily impart perfume when
wet. The grass is called vetiver, khus-khus, and khas-khas. It has
escaped from cultivation in Louisiana. Vetiver is a robust grass
with a large erect panicle, the slender whorled branches ascending,
naked at the base, the awnless spikelets muricate.
1 Bull. Misc. Inf. Kew 1906: 297. 1906.
264 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 160. Big bluestem, Andropogon furcatus. Plant, X \ ', pair of spikelets with
joint of rachis, X 5.
Bui. 772, U. S. Dept. of Agriculture.
PLATE XIX.
BLUESTEM (ANDROPOGON FURCATUS).
Jlocky fcanks of the Pot cmac. A valuable forage grass on the prairies of the Mississippi Valley.
Bui. 772, U. S. Dept. of Agriculture.
PLATE XX.
GAMA GRASS (TRIPSACUM DACTYLOIDES). NEAR WASHINGTON, D. C.
GENERA OF GRASSES OF THE UNITED STATES. 265
FIG. 161. Andropogon saccharoides. riant, X J ; pair of spikelets with joint of rachis
(at left), the pedicellate spikelet showing a little at right, X 5.
266 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Arthraxon Beauv., Ess. Agrost. 111. 1812. Type species, A.
ciliaris Beauv. This Old World genus is represented in North
America by A. qiwrtwiwms (A. Eich.) Nash, introduced into Ja-
maica and Guadaloupe, and by A. ciliaris cryptatherus Hack., estab-
lished in the vicinity of Washington, D. C. The latter is a creeping
slender grass with thin cordate-lanceolate blades, the inflorescence
of several slender racemes in a cluster.
133. HOLCUS L.
(SorgJmm Pers.)
Spikelets in pairs, one sessile and fertile, the other pedicellate,
sterile but well developed, usually staminate, the terminal sessile
spikelet with two pedicellate spikelets.
Annual or perennial, tall or moderately tall grasses, with flat
blades and terminal panicles of 1 to 5 jointed tardily disarticulating
racemes. Species about six, one Mexican, the others in the Old
World ; two cultivated or introduced into America.
Type species: Holcus sorghum L.
Holcus L., Sp. PI. 1047, 1753; Gen. PL, ed. 5, 469. 1754. Linnreus describes
seven species, H. sorghum, H. saccharatus, H. halepensis, H. lanatus, H. odo-
ratus, H. laxus, and H. striatus. The selection of the type species is of
particular importance in this genus, because it affects the generic name of
the group containing the cultivated sorghums. The first three of the original
seven species were segregated from the others in 1763 by Adanson, who applied
to them the old name sorghum, used by Bauhin and other pre-Linnsean authors
for the cultivated sorghums. This name was accepted by most of those subse-
quent authors who recognized the group as a genus distinct from Andropogon,
and as a subgeneric name by those who held it to be a subgenus of Andropogon.
Of the remaining four of the original seven species of Holcus all but H. lana-
tus were early assigned to other genera, leaving H. lanatus in possession of the
generic name and in effect making this residual species the type of the genus.
Linnaeus, however, in all the editions of the Genera Plantarum and in the
Hortus Cliffortianus and the Hortus Upsaliensis used the name Holcus for
sorghum only. The description and the synonymy in all cases apply only to the
first three of the seven species included in the Species Plantarum. Moreover, in
all the editions of the Genera Plantarum Linnaeus cites " Sorgum Mich." While
Micheli 1 gives no description or figure of the genus, we know from Bauhin
and others that Sorgum or Sorghum was in common use for the group in
question. Linna?us uses the old name Sorghum for the trivial or specific name
of the first species, and cites Sorghum of Bauhin as a synonym. It is clear
that the Holcus of Linna?us is the old Sorghum, the other four diverse species
(which do not agree with the generic descriptions in any of the works cited),
evidently being appended for want of a place to put them. According to the
American Code the genera of Lirmseus's Species Plantarum are to be typified
through citations given in his Genera Plantarum of 1754. The reference to
Micheli, the use of sorghum as a specific name, and the descriptions all point
to H. sorghum as the type of the genus Holcus. Holcus lanatus is now referred
to Notholcus, H. odoratus to Torresia (Hierochloe, Savastana), H. laxus to
Uniola, and H. striatus to Sacciolepis. By many authors the genus Holcus as
here understood is included under Andropogon.
Blumenbachia Koel., Descr. Gram. 28. 1802. A single species, " B. halep-
pensis." based on " Holcus Haleppensis Linn." is included.
Sorghum Pers., Syn. PI. 1 : 101. 1805. Four species are included. Holcus
sorghum L., upon which . vulgare Pers. is based, is taken as the type.
. Plant. Gen. 35. 1729.
GENERA OF GRASSES OF TIIK TXITFJ) STATES. 267
Holcus sorghum L. (Andropogon sorghum Brot. ; Sorghum vul-
gare Pers.) has been cultivated from prehistoric times 1 for the seed,
which has been used for food, for the sweet juice, and for forage. In
the United States it is cultivated under the general name of sorghum
or sorgo. There are many races and varieties, the chief of which are
sorgo, kafir, milo, broom corn, shallu, kaoliang, and durra. Sorgo
includes the varieties with sAveet juice, these varieties often being
known collectively as saccharine sorghums.
In this country sorgo is cultivated, chiefly in the region from Kan-
sas to North Carolina, for the juice which is made into sirup and
for foliage which is used for fodder in the Southern States, especially
in the region from Kansas to Texas, where it is often called "cane."
The other races of sorghum are often classed together as non-
saccharine sorghums. The large panicles of one race, broom corn,
grown especially in Illinois, furnish the material for brooms. The
other races are used for forage or for the seed, which is used for
feed. Kafir, milo, and a recently introduced variety, feterita, are
of especial value in the southern part of the Great Plains and other
semiarid regions where dry-land farming is practiced. Kafir, or
Kafir corn, is a rather low form with compact cylindric heads and
awnless spikelets. Milo, or milo maize, is a usually taller form, with
ovate heads, a straight or recurved peduncle, awned spikelets, and
larger seeds. Durra differs from milo in having densely pubescent
grayish or greenish glumes (instead of brown or black and slightly
pubescent), and strongly flattened seeds. Some of these forms are
called Egyptian corn, chicken corn, and Jerusalem corn. The name
chicken corn should be restricted to a variety spontaneous in Louisi-
ana and Mississippi (Holcus sorghum drummondii (Nees) Hitchc.,
Andropogon drumm-ondii Nees, A. sorghum drummondii Hack.).
A recently introduced variety, IIolcus sorghum sudanensis (Piper)
Hitchc. (Andropogon sorghum sudanensis Piper), is now extensively
cultivated for hay in the semiarid regions under the name of Sudan
grass. This is a rather slender annual, 6 to 9 feet tall, the panicle
open and spreading. The absence of rhizomes shows its affinity to
sorgo. Tunis grass is an allied variety (IIolcus sorghum exiguus
(Forsk.) Hitchc., IIolcus exiguus Forsk., Andropogon sorghum ex-
iguus Piper) that has been tried in our Southern States.
The second species of Holcus found in the United States is H.
halepensis L. (fig. 162), known as Johnson grass. This is a perennial
with stout creeping rhizomes. The panicle is open and spreading,
the spikelets awned or awnless. Johnson grass is not so tall as the
open-panicled forms of sorghum, being usually 3 to 5 feet tall, and
1 For a history and classification of sorghum, see Ball, IT. S. I'epl. Aj;r. f Bur. Tl. Ind.
Bull. 175. 1910.
268 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 102. Johnson grass, Holcus halcpcnuis. Plant, X B ; two views of terminal raceme,
one of the pedicellate spikelets fallen, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 269
has narrower blades than plants of sorghum of the same height.
The characteristic difference is the presence of the creeping rhizomes
in the former. Johnson grass is a native of the Mediterranean
region, but is now widely distributed in the warmer parts of
America. In the United States it is common throughout the
South, where it is often a troublesome weed. It is an ex-
cellent and much-used forage grass, but the difficulty of eradicating
it from ground that it has once occupied offsets its forage value.
Johnson grass has become an especially pernicious weed on the
Black Lands of Alabama and Texas. 1
The sorghums and Johnson grass sometimes produce hydrocyanic
acid in sufficient abundance, especially in second growth, to poison
grazing animals.
134. SORGHASTETJM Nash.
Spikelets in pairs, one nearly terete, sessile, and fertile, the other
wanting, only the hairy pedicel being present; glumes coriaceous,
brown or yellowish, the first hirsute, the edges inflexed over the
second; sterile and fertile lemmas thin and hyaline, the latter ex-
tending into a usually well-developed bent and twisted awn.
Perennial, erect, rather tall grasses, with narrow flat blades and
narrow terminal panicles of one to few jointed racemes. Species
about 10 in the warmer parts of the Western Hemisphere, and a
few in Africa; 3 species in the United States east of the Rocky
Mountains.
Type species : Andropogon avenaceus Michx.
Poranthera Raf., Bull. Bot. Seringe 1: 221, 1830, not Rudge, 1811. "Andro-
pogon nutans -[L.] et ciliatus [Ell.])" are cited. These names apply to the
same species, Sorghastrum nutans (L.) Nash.
Sorghastrum Nash, in Britton, Man. 71. 1901. Only one species described.
S. avenaceum (Michx.) Nash.
Chalcoelytrum Lunell, Amer. Midi. Nat. 4 : 212. 1915. The name proposed to
replace Sorghastrum Nash, which, being built on Sorghum, is considered unde-
sirable.
The units of the inflorescence are racemes reduced to one or two
joints, or in Sorghastrum nutans sometimes four or five. The slen-
der, villous rachis disarticulates at the top of each joint, the spikelets
falling with two villous stalks attached, one the rachis joint, the
other the pedicel of the obsolete sterile spikelet. The articulation is
more or less oblique, leaving a bearded blunt callus or, in some South
American species, a long, sharp callus. In S. nutans the racemes not
infrequently occur in pairs with a sessile spikelet in the fork, that
is, the pedicel of the sterile spikelet of the lowest joint has been re-
placed by a short raceme of one or two joints.
1 For methods of eradication, see Cates and Spillman, U. S. Dept. Agr., Farmers' Bull.
279. 1907.
270 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
The commonest species of the genus in the United States is Sor-
ghastrum nutans (L.) Nash (fig. 163), sometimes called Indian reed
or Indian grass. This is a tall, erect grass with handsome bronze-
colored panicles as much as a foot long, the awns about half an inch
long, the anthers brilliant yellow. The species is found in prairies
and open woods throughout the eastern United States and south-
westward to Arizona and Mexico. It is a common constituent of
prairie hay in the eastern part of the Great Plains region.
Two other species are found in the Southern States, both with
awns about an inch long, Sorghaetrum elliottii (C. Mohr) Nash, with
pedicels villous only at the very tip, and S. secundum (Chapm.) Nash,
with a one-sided panicle and pedicels villous along the upper portion.
135. RHAPHIS Lour.
Spikelets in threes, one sessile and perfect, the other two pedicellate
and sterile, or sometimes a pair below, one fertile and one sterile;
fertile spikelet terete, the glumes coriaceous; sterile and fertile
lemmas thin and hyaline, the latter long-awned.
Perennial grasses, or our species annual, with open panicles, the
three spikelets (reduced racemes) borne at the ends of long, slender,
naked branches. Species about 20, all in the tropical regions of the
Eastern Hemisphere except the 1 found in the southern United States.
Type species: Rhaphis trivialis Lour.
Rhaphis Lour., Fl. Cochinch. 553. 1790. Only one species described, which
is the same as Andropojion- (idculatus Retz. Some authors have thought the
name Rhaphis was invalidated by the earlier Rhapis L. f. (1789), a genus of
palms. The names have a different derivation and a different pronunciation,
and the one does not invalidate the other.
Pollinia Spreng., Pugill. 2: 10, 1815, not Pollinia Trin., 1832. Type species,
P. gryllus Spreng. (Andropogon gryllus L. ). Several species are described,
but the generic characters are given under the first species.
Centrophorum Trin., Fund. Agrost. 106, pi. 5. 1820; Type species, C. chincnse
Trin. (Andropoyon (iciculfttu* Retz.), the only one described.
Chrysopogon Trin., Fund. Agrost. 187. 1820. Type species, Andropogon
gryllus L. Two species are mentioned, C. gryllus and C t aciculatus, but an
illustration of the first is cited.
The only species occurring in the United States is Rhaphis pauci-
flora (Chapm.) Nash (fig. 164), an annual found in Florida and
Cuba. This has the aspect of a species of Stipa, the spikelets with
their long awns and barbed callus resembling the fruit of Stipa
spartea. The long slender branches of the few-flowered panicle bear
a terete, brown, sessile fertile spikelet and two slender sterile pedicels,
each with a slender glume. The peduncle disarticulates by a long
oblique line through the thickened villous end, the portion separating
with the spikelet being densely brown-villous, this forming a long
sharp callus. The glumes are coriaceous and at maturity separate
somewhat, the spikelet gaping at the apex. The palea is present, but
GENERA OF GRASSES OF THE UNITED STATES. 271
FIG. 163. Indian grass, * Sorghastrum nutans. Plant, X i; spikelet with pedicel at
left and rachis joint at right, X 5.
272 BULLETIN 772, U. S. DKI'AIITM KNT OF AGRICULTURE.
Fio. 164. Rhavhis jHiucijIora. Plant with <>M splkHK still jiUiirln'd to roots, X
fruiting fertile spikelet, X 5.
GENERA OF GRASSES OF THE UNITED STATK-. 273
much shorter than the very thin sterile and fertile lemmas. The
awn is about 6 inches long, twisted and bent. The species before
maturity furnishes forage on the grassy pinelands of southern
Florida.
136. HETEBOPOGON Pers.
Spikelets in pairs, one sessile, the other pedicellate, both of the
lower few to several pairs staminate or neuter, the remainder of the
sessile spikelets perfect, terete, long-awned, the pedicellate spikelots,
like the lower, staminate, flat, conspicuous, awnless; glumes of the
fertile spikelet equal, coriaceous, the first brown-hirsute, infolding
the second ; lemmas thin and hyaline, the fertile one narrow, extend-
ing into a strong bent and twisted brown awn ; palea wanting; glumes
of the staminate spikelet membranaceous, the first green, faintly many
nerved, asymmetric, one subrnarginal keel rather broadly winged,
the other wingless, the margins inflexed, the second glume narrower,
symmetric ; lemmas hyaline ; palea wanting.
Annual or perennial, often robust grasses, with flat blades and soli-
tary racemes terminal on the culms and branches ; rachis slender, the
lower part, bearing the pairs of staminate spikelets, continuous, the
remainder disarticulating obliquely at the base of each joint, the joint
forming a sharp barbed callus below the fertile spikelet, the pedicel-
late spikelet readily falling, its pedicel remaining, obscured in the
hairs of the callus. Species about seven, in the warmer regions of
both hemispheres; two in the United States, from Florida to Arizona.
Typo spocios : Ifftnrop'jf/rm yJnl<"r Pers.
Heteropogon Pers., Syn. PI. 2 : 533. 1807. Persoon describes two species, H.
ylaber, of which he gives as synonyms Andropoyon allioni DC. and A. cf/n-
tortus All., and H. hirtun, of which ho gives as a synonym Andropoyon con-
tortiiH L. The first ;li<- type.
Spirotheros Raf., Bull. Hot. Serins 1 : 221. 1830. A single species, " Stipa
melanocarpa, Muhl., Andropoyon nwianwaritus Ell.," is given.
The two species in the United States are Heteropogon contortus
(L.) Beauv. (fig. 105), a perennial, 1 to 3 feet tall, the first glume
of the staminate spikelets papillose-pilose, sometimes sparsely so,
anrl 77. melo/nacoppus (Ell.) Benth., an annual, 4 to 7 feet tall and
often much branched, the first glume of the staminate spikelets bear-
ing a row of glands along the back. The first species is found in
rocky places from Texas to Arizona. The second is found in Florida,
Georgia, and Alabama; also in Arizona. The oil glands on the in-
florescence of the latter give the plant an odor like that of citronella
oil.
Heteropogon contortus is an important forage grass but does not
extend far into the United States. In the Hawaiian Islands, where
it is called pili, it is an important range grass on the drier areas. It
was used by the natives to thatch their grass huts. The mature fruits
are injurious to sheep.
97769 19 Bull. 772 - 18
274 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 165. Heteropogon contortus. Plant, X J ; fruiting fertile spikelet, X 5.
GENERA OF GRASSES OF THE UNITED STATES. 275
137. TRACHYPOGON Nees.
Spikelets in pairs, along a slender continuous rachis, one nearly
sessile, staminate, awnless, the other pedicellate, perfect, long-awned ;
the pedicel of the perfect spikelet obliquely disarticulating near the
base, forming a sharp barbed callus below the spikelet; first glume
firm-membranaceous, rounded on the back, several-nerved, obtuse;
second glume firm, obscurely nerved ; fertile lemma narrow, extend-
ing into a stout twisted and bent or flexuous awn; palea obsolete;
sessile spikelet persistent, as large as the fertile spikelet and similar
but awnless.
Perennial, moderately tall grasses, with terminal spikelike racemes,
these single or clustered. Species about seven, Mexico to South
America, one extending into the southwestern United States.
Type species : Andropogon montufari H. B. K.
Trachypogon Nees, Agrost. Bras. 341. 1829. The first of the 13 species de-
scribed, T. montufari, based on Andropogon montufari, is selected as the type.
The first five species are all that are now retained in Trachypogon.
Our only species is Trachypogon montufari (H. B. K.) Nees (fig.
166), found in southern Arizona and southwestern New Mexico, an
erect slender perennial with solitary racemes, the feathery awns
about 1| inches long. It is an important constituent of the grazing
areas of Central and South America.
138. ELYONTTRUS Humb. and Bonpl.
Spikelets in pairs along a somewhat tardily disarticulating rachis,
the joints and pedicels thickened and parallel, the sessile spikelets
appressed to the concave side, the pedicellate spikelet staminate,
similar to the sessile one, both awnless, the pair falling with a joint
of the rachis; first glume firm, somewhat coriaceous, depressed on
the back, the margins inflexed around the second glume, a line of
balsam glands on the marginal nerves, the apex entire and acute
or acuminate, or bifid with aristate teeth; second glume similar to
the first ; sterile and fertile lemmas thin and hyaline ; palea obsolete.
Erect, moderately tall perennials, with solitary spikelike, often
woolly racemes. Species about 15, in the warmer regions of both
hemispheres; two species extending into our Southern States.
Type species : Elyonurus tripsacoides Humb. and Bonpl.
Elyonurus Humb. and Bonpl., Willd. Spec. PI. 4 : 941. 1806. Only one species
is described.
Elyonurus tmpsacoides (fig. 167), with inconspicuously hairy
spikes, extends from Florida to Texas, and E. 'barbiculmis Hack.,
with conspicuously woolly spikes, is found from western Texas to
Arizona. The species of Elyonurus are important grazing grasses in
the savannas and plains of tropical America.
276 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 1G6. Tracliypoyon montufari. Plant, X i ; fruiting fertile spikelet, X 5.
GENERA OF GRASSES OF THE UNITED STATES.
277
FIG. 167. Elyonurus tripsacoides. Plant, X J ; two views of a pair of spikelets with a
joint of the rachis, X 5.
278 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
139. MANISURIS L.
(Rottbocllia L. f.)
Spikelets awnless, in pairs at the nodes of a thickened articulate
rachis, one sessile and fertile, the other pedicellate and sterile, the
pedicel thickened and appressed to the rachis, the sessile spikelet
fitting closely against the rachis, forming a cylindric or subcylindric
spike; glumes obtuse, awnless, the first coriaceous, fitting over the
hollow containing the spikelet, the second less coriaceous than the
first; sterile lemma, fertile lemma, and palea thin and hyaline, in-
closed within the glumes; pedicellate spikelet reduced, often rudi-
Perennial slender, moderately tall, or tall grasses, with usually
numerous smooth cylindric or flattened spikes, single on the culms
and branches. Species about 30, in the warm regions of both hemi-
spheres ; 5 in the southern United States.
Type species: Manisuris myuros L.
Manisuris L., Mant. PI. 2 : 164. 1771. Only one species described.
Rottboellia L. f., Nov. Gram. Gen. 22, pi. 1, 1779 (Amoen, Acad. 10. 1790),
not Scop., 1777. In a note appended to the description of the genus is the
statement, " Hue pertinent Aegilops Incurvata & Exaltata S. N., p. 762, aeque
ac Panicum Dimidiatum S. N., p. 90." The second species, being the one illus-
trated, is the type.
Stegosia Lour., Fl. Cochinch. 1: 51. 1790. Type, S. cochinchinensis Lour.,
the only species described.
Hemarthria R. Br., Prodr. FL Nov. Holl. 207. 1810. Two species described,
H. compressa and H. uncinata. The first species, based upon Rottboellia com-
pressa L. f., is chosen as the type.
Lodicularia Beauv., Ess. Agrost. 108, pi. 21, f. 6. 1812. A single species is
included, L. fasciculata, based on Rottboellia fasciculata Desf. (R. fasciculata
Lam. evidently intended).
Coelorhachis Brongn., in Duperr. Bot Toy. Coquille 64. 1829. The type is
Aegilops muricata Retz., on which is based Coelorhachis muricata, the only
species described.
The species of Manisuris found in the United States are nowhere
abundant and are of little economic importance, though they may
furnish some forage. Manisuris fasciculata (Lam.) Hitchc. has
flattened spikes. The other three species have cylindric spikes.
In these the first glume is variously marked, being somewhat pitted
in M. cylindrica (Michx.) Kuntze (fig. 168), tessellate in M. tessel-
lata (Steud.) Scribn., and transversely wrinkled in M. rugosa (Nutt.)
Kuntze.
140. RYTILIX Raf.
(Hackelochloa Kuntze, Manisuris of authors.)
Spikelets awnless, in pairs, the rachis joint and pedicel grown
together, the two clasped between the edges of the globose alveolate
first glume of the sessile spikelet; pedicellate spikelet conspicuous,
staminate.
A much-branched annual with flat blades, the numerous spikes
single and more or less inclosed in the sheathing bract, these some-
GENERA OF GRASSES OF THE UNITED STATES.
279
PIG. 168. Manisuris cylindrica. Plant, X ; sessile spikelet and joint of rachis, x 5 ;
joint of rachis with sterile pedicel and rudimentary spikelet, the fertile spikelet at
right. X 5.
280 BULLETIN 772, TJ. S. DEPARTMENT OF AGRICULTURE.
what clustered in the axils of the foliage leaves. Species one, in
the tropical regions of the world.
Type species: Manisuris granularis Swartz.
Rytilix Raf., Bull. Bot. Seringe 1: 219. 1830. Rafinesque cites "Manisuris
granularis et Myurus Auct" and lists one species Rytilix glandulosa. The first
species cited is chosen as the type.
Hackelochloa Kuntze, Rev. Gen. PI. 2 : 776. 1891. Kuntze restores Manisuris
to its Linnsean sense and, overlooking Rytilix Raf., proposes Hackelochloa for
Manisuris Swartz, with H. granu-
laris, based on Cenchrus granularis,
as the type.
Rytilix granularis (L.)
Skeels (fig. 169) is a tropical
weed which extends into the
United States from Florida
to Arizona. The little pitted
globose spikelets are very char-
acteristic.
FIG. 169. Rytilix granularis. Plant, X * ; a single raceme, X 2 ; two yiews of a pair
of spikelets with joint of rachis and pedicel grown together, X 5.
14. TRIPSACEAE, THE CORN TRIBE.
141. TBIPSACUM L.
Spikelets unisexual ; staminate spikelets 2-flowered, in pairs on one
side of a continuous rachis, one sessile, the other sessile or pedicellate,
similar to those of Zea, the glumes firmer ; pistillate spikelets single
GENERA OF GRASSES OF THE UNITED STATES. 281
and on opposite sides at each joint of the thick, hard articulate lower
part of the same rachis, sunken in hollows in the joints, consisting of
one perfect floret and a sterile lemma ; first glume coriaceous, nearly
infolding the spikelet, fitting into and closing the hollow of the
rachis; second glume similar to the first but smaller, infolding the
remainder of the spikelet; sterile lemma, fertile lemma, and palea
very thin and hyaline, these progressively smaller.
Robust perennial grasses, with usually broad flat blades and
monoecious terminal and axillary inflorescences of 1 to 3 spikes, the
pistillate part below, breaking up into bony, seedlike joints, the
staminate above on the same rachis, deciduous as a whole. Species
about seven, all American, extending from the middle United States
to northern South America ; three species in the United States.
Type species : Coix dactyloides L.
Tripsacum L., Syst. Nat., ed. 10, 2: 1261. 1759. Type the first of the two
species described, T. dactyloides, based on Coix dactyloides L., and T. hermaph-
roditum. The second species, based on " Cenchrus 2, Brown. Jam. 367," is
now referred to Anthephora.
Dactylodes Zanoni-Monti ; Kuntze, Rev. Gen. PI. 2 : 772. 1891. Two species
are included, D. angulatum, based on Coix angulatus Mill., and D. fasciculatum,
based on Tripsacum fasciculatum Trin. Coix angulatus, which is the same as
Tripsacum dactyloides, is taken as the type.
The common species in the United States is Tripsacum dactyloides
(PL XX; fig. 170), a robust perennial, 3 to 6 feet tall, with broad
blades, the terminal spikes mostly in threes, the axillary spikes mostly
solitary. This species, called gama grass, is found in moist places
from Connecticut to Texas and Florida. It is a good forage grass,
but is usually not abundant enough to be of much importance. A
second species, T. floridanum Porter, with narrow blades, is found in
southern Florida, and a third species, T. lemmoni Yasey, with pilose
lower sheaths, is found in Arizona.
142. EUCHLAENA Schrad.
Staminate spikelets as in Zea; pistillate spikelets single, on oppo-
site sides, sunken in cavities in the hardened joints of an obliquely
articulate rachis, the indurate first glume covering the cavity; sec-
ond glume membranaceous, the lemmas hyaline. Spikes infolded in
foliaceous bracts or husks, 2 to several of these together inclosed in
the leaf sheaths.
The one species generally recognized is Euchlaena mexicana
Schrad., a tall annual with somewhat the aspect of corn (Zea mays),
a native of Mexico.
Type species : Euchlaena mexicana Schrad.
Euchlaena Schrad., Ind. Sem. Hort. Goettingen. 1832. Only one species
described. The specimen was collected by Dr. Miihlenfordt in Mexico.
The genus is little known. Several species have been proposed,
but they are doubtfully distinct from Euchlaena mexicana. An un-
282 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 170. Gama grass, Tripsacum daetyloides. Rhizome, leaves, and inflorescence, X I ;
pistillate spikelet and joint of rachis, X 5 ; pair of staminate spikelets with joint of
rachis, X 5.
GENEKA OF GRASSES OF THE UNITED STATES. 283
described species from Mexico is a perennial with simple culms and
creeping rhizomes. A form which is supposed to be the original
E. mexicana is cultivated occasionally in our Southern States, where
it is known as teosinte (fig. 171). This is a tall, stout grass, usually
branching at the base and forming large clumps. The tassel is like
that of corn, and the fascicles of spikes, inclosed in husks with the
long styles or silk hanging from the apex, bear a superficial resem-
blance to the ears of corn. Teosinte is cultivated chiefly for soiling.
It has sometimes been called Reana luxurians Durieu.
143. ZEA L., maize, Indian corn.
Spikelets unisexual; staminate spikelets 2-flowerecl, in pairs, on
one side of a continuous rachis, one nearly sessile, the other pedicel-
late; glumes membranaceous, acute; lemma and palea hyaline;
pistillate spikelets sessile, in pairs, consisting of one fertile floret
and one sterile floret, the latter sometimes developed as a second,
fertile floret; glumes broad, rounded or emarginate at apex; sterile
lemma similar to the fertile, the palea present; style very long and
slender, stigmatic along both sides well toward the base.
A tall annual grass, with broad, conspicuously distichous blades,
monoecious inflorescences, the staminate flowers in spikelike racemes,
these numerous, forming large spreading panicles (tassels) terminat-
ing the stems, the pistillate inflorescence in the axils of the leaves,
the spikelets in 8 to 16 or even as many as 30 rows on a thickened,
almost woody axis (cob), the whole inclosed in numerous large
foliaceous bracts (husks), the long styles (silk) protruding from the
top as a silky mass of threads. In the common varieties of corn the
floral bracts are much shorter than the kernel and remain on the cob
when the kernels are shelled. 1 Species one.
Type species : Zea mays L.
Zea L., Sp. PI. 971, 1753; Gen. PI., ed. 5, 419. 1754. Zca mays is the
only species described.
Mays Tourn., in Gaertn. Fruct. and Sem. 1 : 6, pi. 1. 1788. The single species,
If. zea Gaertn., is the same as Zea mays L.
Mayzea Raf., Med. Fl. 2 : 241. 1830. Two species included. Zea mays L., on
which the first species, M. ccrealis, is based, is taken as the type.
In the United States Zea mays L. (figs. 172, 173) is usually called
corn; in Europe and sometimes in America, especially in literature,
it is called maize. Corn is one of the important economic plants of
the world, being cultivated for food for man and domestic animals
and for forage. It originated 2 in America, probably on the Mexican
Plateau, and was cultivated from prehistoric times by the early
1 For note on the structure of the maize ear as indicated in Zea-Euchlaena hybrids, see
Collins, Journ. Agr. Res. 17: 127-135. 1019.
2 For a note on the origin of maize, see Collins, Journ. Washington Acad. Sci. 2 : 520.
1912.
284 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
FIG. 171. Teosinte, EucJilaena mcxicana. Sketch of plant, much reduced ; pistillate in-
florescence inclosed in bract (a) and with portion of bract removed (b), X 1 ; lateral
view of Joint of rachis and the fertile spikelet (c), X 2; dorsal view of same, show-
ing first glume (d), X 2.
GENERA OF GRASSES OF THE UNITED STATES. 285
FIG. 172. Corn, Zed mays. Sketch of plant, much, reduced.
286 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
PIG. 173. Corn, Zed mays. Tistillate inflorescence (ear) and two branches of staminate
inflorescence (tassel), X \ ; pair of pistillate spikelets attached to rachis (cob) with
mature caryopses (grains), the second glume showing, X 2; single pistillate spikelet
soon after flowering showing first (at left) and second glumes and young grain, X 2 ;
staminate spikelet, X 2.
GENERA OF GRASSES OF THE UNITED STATES. 287
races of American aborigines, from Peru to middle North America.
Several races of corn are grown in the United States, 1 the most im-
portant being dent, the common commercial field sort, flint, sweet, and
pop. Pod corn (Z. mays tunicata Larr.), occasionally cultivated as a
curiosity, is a variety in which each kernel is enveloped in the
elongate floral bracts. A variety with variegated leaves (Z. mays
japonica Korn.) is cultivated for ornament.
144. Coix L.
Spikelets unisexual; staminate spikelets 2-flowered, in twos or
threes on the continuous rachis, the normal group consisting of a pair
of sessile spikelets with
a single pedicellate
spikelet between, the lat-
ter sometimes reduced
to a pedicel or wanting;
glumes membranaceous,
obscurely nerved;
lemma hyaline, nearly
as long as the glumes,
awnless, 5-nerved ; palea
hyaline, a little shorter
than the lemma; sta-
mens 3 ; pistillate spike-
lets 3 together, 1 fertile
and 2 sterile at the base
of the inflorescence ; fer-
tile spikelet consisting
of 2 glumes, 1 sterile
lemma, a fertile lemma,
and a palea ; glumes sev-
eral-nerved, hyaline be-
low chartaceous in the
Tipper narrow pointed FIG. 174. Job's-tears, Coix lachryma-jobi. Tipper por-
part, the first very
broad, infolding the spikelet, the margins infolded beyond the 2
lateral stronger pair of nerves, the second glume narrower than the
first, keeled ; sterile lemma about as long as the second glume, similar
in shape but a little narrower, hyaline below, somewhat chartaceous
above; fertile lemma hyaline, narrow, somewhat shorter than the
sterile lemma ; palea hyaline ; narrow, shorter than the lemma ; sterile
spikelets consisting of a single narrow tubular glume as long as the
fertile spikelet, somewhat chartaceous.
1 See Montgomery, The Cora Crops, 15, 1913 : Sturtevant, U. S. Dept. Agr., Off. Exp.
Sta. Bull. 57. 1899.
288 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE.
Tall branched grasses with broad flat blades, the monoecious in-
florescences numerous on long, stout peduncles, these clustered in the
axils of the leaves, each inflorescence consisting of an ovate or oval,
pearly white or drab, beadlike, very hard, tardily deciduous involucre
(much modified sheathing bract) containing the pistillate lower
portion of the inflorescence, the points of the pistillate spikelets and
the slender axis of the staminate portion of the inflorescence pro-
truding through the orifice at the apex, the staminate upper portion
of the inflorescence 2 to 4 cm. long, soon deciduous, consisting of
several clusters of staminate spikelets. Species about four, one
widely distributed in tropical countries, the others in the East Indies.
Type species: Coix lacliryma-joM L.
Coix L., Sp. PI. 972, 1753; Gen. PI., ed. 5, 419. 1754. Linnaeus describes
two species, C. lachryma-jobi and C. dactyloides. The reference in the Genera
Plantarum (above cited) is to Tournefort's plate 302, which represents the first
species.
Coix lachryma-joli L. (fig. 174), known as Job's-tears and some-
times as Christ's-tears, is cultivated in all tropical countries for orna-
ment and has escaped into waste places, especially around dwellings.
It is also cultivated in greenhouses and sometimes in the open in
warm temperate regions. The name Job's-tears comes from the fan-
cied resemblance of the fruit to tears. The fruits, or so-called seeds,
are used for a variety of purposes, such as beads, and for rosaries.
LIST OF NEW SPECIES AND NEW NAMES.
Page.
Aspris capillaris (Host) Hitchc.
Aira capillaris Host 116
Blepharidachne benthamiana
(Hack.) Hitchc 78
Munroa bentMmiana Hack.
Bracmaria cilia tissima
(Buckl.) Chase 221
Panicum ciliatissimum
Buckl.
Capriola dactylon maritima
(H. B. K.) Hitchc 179
Cynodon maritimus H. B, iK.
Echinochloa crusgalli edulis
Hitchc 238
Panicum frumentaceum
Eoxb., 1820, not Salisb.,
1796.
Echinochloa crusgalli zelayen-
sis Hitchc 238
Oplism enus zelayensis
H. B. K.
Epicampes emersleyi (Vasey)
Hitchc 144
Muhlcnlergia emersleyi
Yasey.
Page.
Epicampes subpatens Hitchc.
sp. nov 144
Fluminea festucacea (Willd.)
Hitchc 38
Arundo festucaoca Willd.
Muhlenbergia andina (Nutt.)
Hitchc 145
Calamagrostis andina
Nutt.
Muhlenbergia montana (Nutt.)
Hitchc 146
Calycodon montanum
Nutt.
Osterdamia japonica (Steud.)
Hitchc 166
Zoysia japonica Steud.
Pholiurus incuryatus (L.)
Hitchc 106
Aegilops incurvata L.
Polypogon lutosus (Poir.)
Hitchc 138
Agrostis lutosa Poir.
Triodia flaya (L.) Hitchc. 76
Poa flava L.
INDEX.
[Synonyms are in italic type. The page numbers of the principal entries are set in heavy-face type.]
.Page.
Abola 133
Acamptoclados 46
Achyrodes 68
aureum 68, 69
Achyrophyton 166
Adobe grass 232
Aegilops aromaticum 185
exaltata 278
hystrix 96
incurvata 106, 278
muricata 278
Aegopogon 169
cenchroides 169
tenellus 169,171
Agraulus 127
Agropyron 87-89
cristatum 87
dasystachyum 87
repens 87, 88
saxicola 88
scribneri 88
smithii 87,89,94
spicatum 88
subvillosum 87
tenerum 87
triticeum 87
Agropyrum 87
Agrosticula 150
muralis 150
Agrostideae 13-15, 121-165
Agrostis 13, 125, 127-132
aequivalvis 127, 132
alba 128
maritima 129
vulgaris 129
algida 132
alpina 127
arachnoides 127
arundinacea 127
canina 127, 129
capillaris 129
crudata 187, 189
diegoensis 130
elliottiana 127, 128, 132
97769 19 Bull. 772 19
Page.
Agrostis exarata 129
microphylla 128
exigua 128
hallii 128
hiemalis: 127, 130
howellii 128
indica. 127, 150
interrupta 127
juncea 150, 166
littoralis 138
lutosa 138
maritima 129
matrella 166
miliacea 127, 158
minima 127
palustris 128, 129
paradoxa 127
perennans 127, 130
radiata 189
spica-venti 127, 128, 130-131
stolonif era 125, 127, 129
tennis 129
thurberiana 127
ventricosa 142
verticillata 127
virginica 127
vulgaris 129
Aino millet 245
Aira 114-116
aquatica 47
caerulea 50
caespitosa 114-116
caryophylka 116
cristata 107
danthonioides 116
flexuosa - 114
melicoides 108
montana 114
obtusata 110
praecox 116
purpurea 76
spicata 114
Airochloa 107
Alfa grass 161
Alfalfa : 3
289
290
INDEX.
Page.
Alkali grass 58
eaccaton 15.0, 152
Alloiatheros 187
Alopecurus 13, 136, 137
alpinus 137
aristulatus 137
californicus 137
geniculatus 137
aristulatus 137
hordeiformis 137
monspeliensis 137
occidentalis 137
pratensis 136, 137
Amagris 121
Ammophila 123
arenaria 123, 124
arundinacea 123
Amphicarpon 19, 249-251
amphicarpon 250
floridanum 250
purshii 250,251
Amphilophis ; 260
Anastrophus 223, 224
Anatherum 263
zizanioides 263
Andropogon 258, 260-263
aciculatus 270
allioni 273
alopecuroides 260
ambiguus 187
argenteus 263
avenaceus 269
barbinodis 263
bicornis 260
brevifolius 260
ciliatus 269
dtratus 263
condensatus 260
contortus 260, 273
distachyos 260
divaricatus 260
drummondii 267
elliottii ' 261
fasdculatus 260
furcatus 263, 264
gryllus 270
hirtus 260
insularis 215
ischaemum 260
macrurus 260
melanocarpus 273
montufari 275
muricatus 263
Page.
A ndropogon nardus 260, 263
nutans 260, 269
perforatus 263
polydactylon 189
saccharoides 263, 265
laguroides 263
schoenanthus 260
scoparius 260, 261
sessiliflorus 260
sorghum 267
drummondii 267
exiguus 267
sudanensis 267
tetrastachyus 260
torreyanus 260, 263
vaginatus 260
virginicus 260-261, 262
Andropogoneae 2, 20-21, 252-280
Anemagrostis 127
Anthaenantia 213-214
rufa..... 214
villosa 214
Anthipsimus 2
gonopodus 2
Anthochloa 71, 73
colusana 73
lepidula 71
rupestris 71
Anthopogon 187
lepturoides 187
Aiithoschmidtia 83
Anthoxanthum 201-202
aristatum 202
indicum 201
odoratum 201-202
paniculatum 201
puellii 202
Apera 127, 130
spica-venti 127, 131
Aplexia 206
Aristida 161, 163-165
adscensionis 163
americana 191
bromoides 163
californica 163
desmantha 163
dichotoma 163
fendleriana 163
gracilis..... 163
lanosa 163
longiseta 163, 165
oligantha 163,164
purpurea 163
INDEX.
291
Aristida scabra .
schiedeana.
stricta
tuberculosa.
Arizona fescue. .
Arrhenatherum .
avenaceum..
Page.
163
163
163
163
31
113
113
elatius 113,114
bulbosum 113
Arthraxon. . 266
ciliaris 266
cryptatherus 266
quartinianus 266
Arundinaria 22-24
japonica 8
macrosperma 22
* tecta 22
Arundo .' 60,63
arenaria 60, 123
bambos 60
calamagroslis 60, 121
donax 38, 60, 62
versicolor 60
epigejos 60
feslucacea 38
karka 64
phragmites 64
versicolor 60
Asperella 98
Jiyslrix 98
Aspris. . 12, 116
capillaris 116
caryophyllea 116, 117
praecox 116
Athernotus 121
Atheropogon 191
apludioides 191
Aulaxanthus 214
dliatus 214
rufus 214
Aulaxia 214
A vena 110-113
barbata 112,113
calidna (calycina) 118
elatior 111,113
fatua 110, 111, 112, 113
glabrata Ill
Jlavescens 108, 111
fragilis Ill
glumosa 118
pennsylvanicua Ill
pratensis 110
sativa 110, 111, 113
Avena sibirica 110
spicata Ill, 118, 120
sterilis 113
Aveneae 12-13,106-120
Awnless brome-grass 25
Axonopus 523-225
aureus 224
compressus 224
furcatus 225
Bahama grass 179
Bamboo tribe 22-24
Bamboos C8+..22
Bambos bambos 8
vulgaris 8
Bamboseae 8, 22-24
Bambusa {~$
Barley 98, 100, 101
beardless 101
rice 101
tribe 87-106
Barnyard grass , 238, 240
Bauchea 150
karwinskyi 150
Beach-grass 123, 124
Beans 3
Beckmannia 180-182
erucaeformis 181-182
Bennetia 150
Bent, carpet 129
creeping 5, 129
grasses 'l25-132
Rhode Island 5, 129
velvet 129
Bermuda grass 4, 5, 178, 179
Bigbluestem 263,264
Billion-dollar grass 239
Black grama 193
grass 4
sporobolus 151
Blade 5
Blepharidachne 6, 8, 78
benthamiana 78
kingii 78, 80
Blepharoneuron 151-153
tricholepis 151, 153
Blue bunch-grass 4, 31, 88
bunch wheat-grass 88
grama 193, 194
4,38,41-45
annual 44
Canada 44
English 33
Kentucky 41, 44
292
INDEX.
Page.
Bluegrass, little 45
malpais 44-45
Texas 44
joint 121,122
stem 87
big 263,264
little 260,261
Blumenbachia 266
Botelua 191
Bottle-brush grass 98, 99
Bouteloua 4, 191, 193-194
americana 191
aristidoides 193, 194
barbata 191, 194
curtipendula 191, 193, 195
eriopoda 193
filiformis 193
gracilis 193, 194
heterostega 193
hirsuta 191, 193
oligostachya 193
polystachya 194
procumbens 193, 194
prostrata 191, 194
racemosa 191, 193
rothrockii 193
simplex 191
texana 193, 196
triaena 193
Brachiaria 221
ciliatissima 221
erucaeformis 221
platyphylla 221, 223
Brachyelytrum 154-156
aristatum 156
erectum 145, 155, 156, 157
Brachypodium 34
distachyon 34
Brachystylus 107
Briza 45
canadensis . ..' 34
eragrostis 45, 46
maxima 45
media 45, 46
minor 45
Brizopyrum 58
boreale 58
Brome-grass 4, 24-28
awnless 25
downy 29
Hungarian 25
Schrader's 24
smooth. ... 25
Page.
Brome-grass, wild 26
Bromelica 69
(section of Melica) 71
Bromus 24-28
arenarius 28
carinatus 25
ciliatus 25, 26
commutatus 25
cristatus 87
elatior. 28
erectus 25
hordeaceus 28
inermis 25
marginatus 25
porteri 25
purgans 25
racemosus 24
rubens 28
secalinus 24, 25, 27, 28
sterilis 24
tectorum 28, 29
trinii 28
unioloides 24
villosus 28
Broom corn 267
sedge 260, 262
Broom-corn millet 230
Buchloe 197-199
dactyloides 199
Buffalo grass 4, 193, 198, 199, 200
Bulbilis : . 197-199
dactyloides 193, 199, 200
Bunch-grass 150
blue 4, 31, 88
mountain 4, 31
Burro grass 81, 82
Cabrera 224
chrysoblepharis 224
Calamagrostis 121-123
andina 145
brevipilis 123, 125
canadensis 121, 122
langsdorfii 123
longifolia 125
rubescens 123
scabra 123
Calamovilfa 123, 125
brevipilis 125
curtissii 125
gigantea 125
longifolia 125, 126
Calanthera 198
dactyloides 198
INDEX.
293
Page.
Calycodon 145
montanum 145, 147
Campulosus 6, 16, 185
aromaticus 185, 186
floridanus 185
gradlior 185
hirsutus , 185
Canada bluegrass 44
Canary grass 203, 204
seed 204
Canary-grass tribe 199-204
Cane, large 22
maiden 232
small 22, 23
sorghum 267
Capriola 175-179
dactylon 178, 215
maritima 179
Carib grass 221
Carpet grass 4, 5, 224
Carrizo 63, 64
Caryophyllea 116
Catabrosa 47
aquatica 47, 51
Cathestecum 194-196
erectum 196
prostratum 195
Cenchropsis 249
Cenchms 247, 249
capitatus 247
carolinianus 249
echinatus 247, 249
frutescens 247,249
granularis 280
myosuroides 249
pauciflorus 249
racemosus 165, 247
tribuloides 247, 249, 250
Centrophorum 270
chinense 270
Ceratochaete 209
Ceratochloa 24
(section of Bromus) 24
Ceresia 226
elegans 226
fluitans 227
Chaboissaea 146
ligulata 146
Chaetaria 163
capillaris 163
stricta 163
Chaetochloa 241, 243-245
composite 2/3
Page.
Chaetochloa geniculata 243
italica 243, 244
varietal key (under Setaria)
244-245
lutescens 243, 244, 247
macrostachya 243
magna 243
palmifolia 243
sulcata 243
verticillata 243
viridis 243, 244, 247
Chalcoelytrum 269
Chamaeraphis 243
Chasea 229
Chasmanthium 60
gratile 60
Cheat 27
Chess 27
Chicken corn 267
Chloamnia 30
Chlorideae 3, 16-17, 171-199
Chloridopsis 191
Chloris 187
ciliata 187
cruciata 187
elegans 189
falcata 185
* floridana 189
gayana 189
glauca 189
monostachya 185
neglecta 189
petraea 187, 189
polydactyla 187
procumbens 193
radiata 187
verticillata 189
virgata 189, 190
Chloropsis 191
blanchardiana 191
Chlorostis 189
Chondrosium 193
Christ 's-tears 288
Chrysopogon 270
adculatus 270
gryllus 270
Chrysurus 68
cynosuroides 68
Cinna 13, 133-134
arundinacea 133, 134
latifolia 133, 134
poaeformis 133
Cinnastrum... 133
294
INDEX.
Page.
Cinnastrum miliaceum 133
poaeforme 133
Citronella grass 263
Clomena 145
perumana 145
Clover 3
Cocksfoot grass 67
Coelorhachis 278
muricata 278
Coix 287-288
angulatus 281
dactyloides 281, 288
lachryma-jobi 287, 288
Coleanthus 132-133
subtilis 132,133
Colobanthus 110
Colorado grass 232
Corn, Indian 383,285,286
tribe 280-288
Cortaderia 63
argentea 63
Cottea 81, 83
pappophoroides 83, 84
Couch-grass 87
Crab-grasses 215, 217-218
Creeping bent 129
Crested dog's-tail grass 67, 68
Criterion * 98
geniculatus. 98
Crowfoot grass 175* 177
Texas 172
Crypsinna 144
macroura 144
setifolia 144
stricta 144
Crypsis 153-154
aculeata 154
squarrosa 197
Crytostachys 150
vaginata 150
Ctenium 185
carolinianum 185
Culm 5
Curly mesquite 4, 168, 193
Curly-mesquite tribe 165-170
Curtopogon 163
Cut-grass, rice 206, 207
Cymatochloa 227
fluitans 227
repens 227
Cymbopogon 263
citratus 263
nardus 263
Cynodon 175,178
dactylon 178
maritimus 179
Cynosurus 67-68
aegyptius 67, 175
aureus 67, 68
capillaceus 172
coeruleus 67
cristatus 67, 68
cruciatus 172
domingensis 172
durus 67
echinatus 67
gradlis 169
indicus 67
lima 67
monostachyos 172
mucronatus 172
paniceus 67
tenellus 169
virgatus 172
Cyperaceae 3-4
Cyperus rotundus 3-4
Dactylis 64, 67
cynosuroides 67, 183
glomerata 64, 66, 67
Dactyloctenium 175
aegyptiacum 175
aegyptium 175, 177
Dactylodes 281
angulatum 281
fasdculatum 281
Dactylogramma 2
cinnoides 2
Danthonia 118, 120
decumbens 118
provincialis 118
spicata 120
unispicata 12
Darnel 103
DaMa 30
elliottea 30
Dasyochloa 74
avenacea 74
pulchella 74
Davyella 71
Deer-grass 144
Deschampsia 114, 116
caespitosa 116
matthewsii 54
Deyeuxia 121
montana 121
Diarina. . . 51-52
INDEX.
295
Page.
Diarina festucoides 51, 52, 53
Diarrliena '. 51
americana 51
Dichanthelium (subgemis of Pani-
cum) 229
Digitaria 215
humifusa 218
sanguinalis 217
Digraphis 203
arundinacea 203
Dilepyrum.. 145, 156
aristosum 145
minutiflorum.. 145
Dimeiostemon 260
Dimesia 199
Dimorphostachys 227
Dioecious grasses. . 8, 41, 44, 56, 63, 81, 199
Diplachne 172
Diplocea 76
barbata 76
Disarrenum antarcticum 199
Dissanthelium 52-54
californicum 54
sclerochloides 54
supinum 54
Distichlis 56-58
dentata 58
maritima 58
multinervosa 58
spicata 58, 59
stricta 58
texana 58
Dog's-tail grass, crested 67, 68
Dog-town grass 163
.Dropseed 151
sand 151
Durra 267
Eatonia 110, 229
purpurascens 229
Echinochloa 238-240
colonum 238
crusgalli 238, 240
edulis 238
zelayensis 238
walteri 240
Echisachys 165
Egyptian corn 267
Einkorn 89
Eleusine 16, 174-175
coracana 175
filiformis 172
indica 175, 176
mrgata 172
Elionurus. See Elyonurus 275
Elymus 93-94
arenarius 93, 94
canadensis. 93, 94, 95
caput-medusae 93, 94
condensatus 94
flavescens 94
glaucus 94
hystrix 98
macounii 94
mollis 94
salina 94
saundersii 94
sibiricus 93
simplex 94
triticoides 94
virginicus 93, 94
Elyonurus 275
barbiculmis 275
tripsacoides 275, 277
Emmer 89
Endallax.: 203
Endodia 206
English bluegrass 33
Enneapogon 83
desvauxii 83
Epicampes 142-145
berlandieri 144
emersleyi 144
ligulata 144
macroura 145
rigens 144
subpatens 144
Eragrostis 45-47
amabilis 46, 47
caroliniana 47
cilianensis 47, 48
ciliaris 47, 50
eragrostis 46
hypnoides 46, 47
major 47
megastachya 47
oxylepis 47
pectinacea 46, 47, 49
plumosa 47
secundiflora 47
sessilispica. 46
Eremochloa 78
Eremochloe 78
bigelovii 78
Tcingii 78
Erianthus 255, 258
brevibarbis. . 258
296
INDEX.
Page.
Erianthus contortus 258
divaricatus 258
ravennae 258
eaccharoides 258, 259
strictus 258
Eriochloa 219-221
acuminata 221
distachya 220
polystachya 220, 221
punctata 220, 221, 222
subglabra 221
Eriocoma 156
cuspidata 156
Erioneuron 74, 76
Erochloe 46
Erosion 46
Esparto grass 5
Euchlaena 281-283
mexicana 281, 283, 284
Eulalia 255,256
japonica 255
Eustachys 189
petraeus 189
Eutriana 193
bromoides 193
curtipendula 193
Fartis 209
Fendlera 158
rhynchelytroides 158
Fescue, Arizona 4, 31
grasses 28-34
hard 31
meadow 31, 33
red 31,32
sheep's 31
tall 32
tribe 24-86
Festuca 28-34
arizonica. 31
borealis 38
bromoides 30
californica 31
capillata 31
confinis 30, 31
cristate 28
decumbens 28, 74, 118
diandra 51
duriuscula 31
elatior 28, 31, 33
elmeri 31
fasdcularis 172
fluitans 28, 34
heterophylla 31
Page.
Festuca idahoensis 31
ingrata 31
myuros 28, 30
obtusa 31
octoflora 30
ovina 28, 31
rubra 31, 32
sciurea 30
subulata 31
subuliflora 31
tenella 30
unioloides 24
viridula .' 31
Festucaria 34
Festuceae 8-10, 24-28, 196
Feterita 267
Fiber grasses 4, 5
Fiorin 129
Flat- stem 44
Flexularia 2
compressa 2
Floret 5
Fluminea 38
arundinacea. 38
festucacea 38, 40
Foragegrasses 3, 4
Forasaccus 24
Fountaingrass 247
Fowl meadow grass 44
Foxtail grass 96
green 243
meadow 136
millet 243
yellow 243,244
Fussia 116
capillaris 116
caryophyllea 116
praecox 116
Galleta grass 169, 170
Gama grass 281, 282
Gardener's garters 203
Gastridium 141-142
australe 141
lendigerum 142
ventricosum 142
German millet 245
Giant reed 60, 62
Ginannia 117
mollis 117
pubescens 117
Glyceria 34
Glume 5
Gnomonia 30
INDEX.
297
Page.
Golden-top 08, G9
Golden-wonder millet 245
Goose-grass 175, 176
Grains 4
Grama, black 193
blue 193,194
grasses 4, 191, 193-194
side-oats 193, 195
six-weeks 194
tribe 171-199
Gramineae. 3
Grapevine mesquite 232, 235
Graphephormn 108
festucaceum 38
flexuosum 54
Grass, definition 3
Grasses distinguished from sedges. 3
Green foxtail 243
Greenia 135
arJcansana 135
Guinea grass 230
Gymnopogon 185-187
ambiguus 187, 188
brevifolius 187
chapmanianus 187
f oliosus 187
racemosus 187
Gymnostichum 98
hystrix 98
Gymnothrix 246
thourii 246
Gynerium 63
argenteum 63
saccharoides 63
sagittatum 63
Hackelochloa 278, 280
granularis 280
Hair-grass, tufted 116
Hare's-tail grass 143
Harpechloa 185
Hay. 4
grain 4, 113
wild 4, 89, 121
Heleochloa 154
alopecuroides 154
schoenoides 154, 155
Helopus 220
pilosus 220
Hemarthria 278
compressa 278
undnata 278
Herd's-grass 129
Hesperochloa 30
(subgenua of Festuca) 30, 31
Tage.
Heteropogon 273
contortus 273, 274
glaber 273
hirtus 273
melanocarpus 273
Heterosteca 193
jundfolia 193
Ilexarrhena 168
cenchroides 168
Ilierochloe 199
antarctica 199
borealis 199
odorata. 199
Hilaria 4, 167-169
belangeri 168, 193
cenchroides 167, 168
jamesii 169, 170
mutica 169
rigida 169
Himalaya fairy grass 255
Hog millet 230
Holcus 20, 116, 117, 266-269
exiguus 267
fragrans 199
halepensis 266, 267, 268
lanatus 117, 118, 266
laxus 266
odoratus 266
saccharatus 266
sorghum 266, 267
sorghum drummondii 267
exiguus 267
sudanensis . . 267
spicatus 246
striatus 237, 266
Holy grass 199
Homalocenchrus 204-206
monandrus 206
oryzoides 206, 207
virginicus 206
Hordeae 11-12, 87-106
Hordeum 98-101
distichon 98, 99
gussoneanum 101
hexastichon 98, 99
ischnatherum 101
jubatum 98, 101
murinum 98, 101
nodosum 101, 102
pusillum 101
spontaneum 101
vulgare 98,100
trifurcatum 101
zeocriton 98, 101
298
INDEX.
Hungarian brome-grass.
Page.
25
245
Hydrochloa 211
carolinensis 211, 213
fluitans 211
Hydropyrum 209
esculentum 209
Hymenothecium 169
quinquesetum 169
tenellum 169
trisetum 169
unisetum 169
Hystrix 96-98
californica 98
hystrix 98
patula 98, 99
Imperata 252
arundinacea 252
brasiliensis 252
hookeri 252, 254
Indian corn 283, 285, 286
grass 270,271
mountain rice 158
reed 270
rice 3,209
Indian-rice tribe 206-211
Injurious grasses 28,
96, 101, 103, 161, 163, 269, 273
Ixophorus 241
Japanese lawn-grass 166
Jerusalem corn 267
Job's-tears 287, 288
Johnson^grass 4, 267, 268, 269
Juncaceae 3
Juncus gerardi 4
June grass 44
Kafir 4,267
corn 267
Kaoliang 267
Kentucky bluegrass 41
Khas-khas 263
Khus-khus 263
Koeleria 12, 106-107
cristata 107, 108
longifolia ; 107
gracilis 107
pennsylvanica 110
phleoides 28, 107
tuberosa 107
villosa 107
Korean lawn grass 166
Korycarpus 52
arundinaceus ... 52
Page.
Kryp-hwen. 127
Krypven 127
Kursk millet 245
Lagurus 142
cylindricus 252
ovatus 142, 143
Lamarckia 68
aurea 68
Lappago 165
Lappagopsis 224
bijuga 224
Lasiacis 232, 234-236
divaricata 236
Lawn grass 4, 5, 44, 129, 225
Japanese 166
Korean 166
Leersia 204, 205
hexandra 205
lenticularis 206
monandra 205
oryzoides 205
virgata 206
virginica 206
Lemma 5
Lemon grass 263
Lepiurus 106
Leptocercus 105
Leptochloa 16, 171-172
domingensis 172
dubia 172
fascicularis 172
filiformis 172,173
floribunda 172
spicata 174
virgata 172
Leptoloma 218
cognatum 218, 219
Lepturus 103, 105
bolanderi 91
cylindrica 105
filiformis 106
paniculatus 180
repens 105
Lesourdia 81
karwinskyana 81
multiflora 81
Ligule 5
Limnetis 183
cynosuroides 183
juncea 183
polystachya 183
pungens 183
Limnodea 13,134-136
INDEX.
299
Page.
Limnodea arkansana 135
pilosa 136
Little bluestem 260, 261
Lodicularia 278
fasdculata 278
Lodicules 5
Lolium 101, 103
italicum 103
multiflorum 103, 104
perenne 103
temnlentiim 103
Lophochlaena 36
californica 36
Love-grass 49
Luziola 209, 211
alabamensis 211
peruviana 211, 212
Lycunis 13, 139
phalaroides 139
phleoides 139
Lygeum spartum 5
Macronax 22
Maiden cane 232
Maize 283
Malojilla 221, 230
Malpais bluegrass 44-45
Manienie 179
Manila grass 166, 167
Manisuris 278, 280
cylindrica 278, 279
fasciculata 278
granularis 280
myuros 278
rugosa 278
tessellata 278
Manna grass 35
Marram grass 123
Marsh grass 184
Matrella 166
Maydeae 22
Mays 283
zea 283
Mayzea 283
cerealis 283
Meadow fescue 4, 31, 33
foxtail 136-137
grasses 4
Melic grasses 71
Melica 68-71
altissima 69
aristata 71, 72
bella.. 71
Page.
Melica bromoides 69
ciliata 69
geyeri 69, 71
imperfecta. 8, 71
mutica 69, 70
nitens 69, 71
nutans 69
purpurascens 71
smithii 71
spectabilis 71
torreyana 8
Melinideae 18, 212-213
Melinis 212-213
miniitiflora 212-213
Melinum 209
palustre. 209
Merathrepta 118, 120
Merisachne 76
drummondii 76
Mesquite, grapevine 232, 235
Mibora minima 133
Miegia . . 22
Milium 156
amphicarpon 249
dmidnum 224
coerulescens 156, 158
compressum 223
confertum 156
digitatum 224
effusum *. 156,158
lendigerum 141, 142
paniceum 224
paradoxum 158
punctatum 220
ramosum 220
Millet 243
broom-corn 230
foxtail 243
grass 158
- hog 230
pearl 246
proso 230
Texfes 232
tribe 213-251
Milo maize 267
Miphragtes 64
Miscanthus 252, 254, 255
capensis 254, 255 .
japonicus 254
luzonensis 254
nepalensis 255
purpurascens 254
300
INDEX.
Page.
Miscanthus sinensis. ... 254, 255, 256
gracillinms 255
variegatus 255
zebrinus 255
Molasses grass 212-213
Molasses-grass tribe 212-213
Molinia 47, 50
caemlea 50, 52
varia 50
Monanthera 185
Monanthochloe 56
littoralis 56, 57
Monerma 103, 105, 106
monandra 105
Monocera 185
Monoecious grasses 22, 199, 206,
209, 211, 280, 281, 283, 286, 287
Monroa 197
Moulinsia 163
Mountain bunch-grass 31
rice, Indian 158
Muhlenbergia 145-148
andina 145
capillaris 145, 147, 148
depauperata 146
emersleyi 145
erecta 155
expansa 145
gradlis 147
ligulata 146
mexicana 146
microsperma 146
montana 145, 147
peruviana 145
repens 146
schreberi 145, 147
squarrosa 146
trifida 147
vaseyana 145
wrightii : 147
Munroa 197
benthamiana 78
mendocina 197
squarrosa 78, 197, 198
Mutton grass 41, 45
Napier grass 247
Nasella 158
Natal grass 4, 241, 242
Nazia 165
aliena 165
racemosa 165
Nazieae 3,15-16, 165-170
Needle grasses 161, 163-165
Page.
Needle-and-thread grass 161
Neeragrostis 46
hypnoides 46
Neostapfia 71
Nevroctola 60
Nevroloma 34
Nimble Will 147
Nothoholcus 118
Notholcus 116-118
lanatus 118, 119
mollis 118
Notonema 127
Nut-grass 3-4
Oat 110, 111, 113
Algerian 113
animated 113
grain hay 4
red 113
tribe 106-120
wild Ill, 112
Oat-grass, tall 113, 114
wild 120
Oedipachne 220
punctata 220
Oil grasses 263
Old-witch grass 232,233
Olyra 252
latifolia 252, 253
Onion grass 71
Oplismenus 237-238
africanus 238
setarius 238, 239
zelayensis 238
Orchard grass 4, 66, 67
Orcuttia 78, 80
californica 80
greenei 80
Ornamental grasses 4, 5, 60
Ortachne 163
Orthopogon 238
aemulus 238
compositus 238
flaccidus 238
imbedllis 238
Oryza 2, 204
sativa 204, 205
Oryzeae 2-3, 18, 204-206
Oryzopsis 156,158
asperifolia 156
hymenoides 156, 158
Osterdamia 15, 165-166
japonica 166
matrella 166, 167
INDEX.
301
Page.
Osterdamia tenuifolia 166
Oxyanthe 64
Oxydenia 172
attenuate, 172
Palea 5
Palm-grass 243
Pampas grass 63
hardy 258
Paneion 41
Panicastrella 247
Panicatae (subfamily) 7-8
Paniceae 18-20, 213-252
Panicularia 34-36
canadensis 34
fluitans 34
grandis 36
nervata 34, 35, 36
pauciflora 36
Panicum 227-232
autumnale : 218
barbinode 229
bulbosum 231-232
capillarc 232, 233
dliatissimum 221
clandestiiium 229
cognatum 218
compositum 238
crusgalli 238
dactylon 178, 215
dichotomiflorum 232
dichotomum 229, 230
dimidiatum 218, 278
dissectum 225
divaricatum 229,236
erucaeforme 221
frumentaceum 238
geminatum 232, 234
gibbum 237
glabrum 218
glaucum 243, 247
hemitomon 232
hians 229
lachnanihum 215
lanatum 215
leucophaeum 215
maximum 230
miliaceum 204, 229, 230
molle 230
monostachyum 227
obtusum 232, 235
plicatum 243
sanguinale 215
sonorum... 232
Tage.
Panicum sulcatum 243
texanum 232
virgatum 229, 231
vinde 241
Pappophorum 88, 85-86
alopecuroideum 83
bicolor 83
gracile 83
nigricans 83
pallidum 83
purpurascens 83
vaginatum 83, 85
wrightii 83, 86
Para grass 221, 229, 230
Paspalum 18,225-227
bifidum 227
ciliatifolium 227
dilatatum 227
dimidiatum 225
distichum 226,227
laeve 227, 228
notatum 227
paniculatum 226
platyculmum 224
pulchellum 227
repens 227
virgatum 226
Pasture grasses 4, 44
Paurochaetium (subgenusof Pani-
cum) 229
Pearl millet 246
Peas 3
Penicillaria 246
spicata 246
Pennisetum 245-247
americanum 246
cenchroides.t 245
glaucum 246, 247
longistylum 247
orientale 245
purpureum 247
ruppelii 247
setosum 245, 247, 248
typhoideum 245, 246, 247
villosum 247
violaceum 245
Pentameris 118, 120
thuarii 120
Phalarideae 6, 17, 199-204
Phalaris 202-204
arundinacea 203
picta 203
canariensis 202-203, 204
302
INDEX.
Page.
Phalaris caroliniana 204
erucaeformis 181, 203
oryzoides 203, 205
pjikoides 203
villosa 214
Phanopyrum 229
gymnocarpon 229
Pharus 211-212
latifolius 211
Phippsia 132
algida 132
Phleum 140-141
alpinum 140
arenarium 140
bellardi 141
graecum 141
pratense 140, 141
schoenoides 140, 153
Pholiurus 105-106
incurvatus 106
Phragmites 64
communis 64, 65
phragmites 64
Phyllostachys 8
Pili 273
Pine-grass 4,123
Piptatherum 156
coerulescens 156, 158
punctatum 156, 158
Piptochaetium 158
Pleopogon 139
setosum 139
Pleuraphis 168
jamesii 168
Pleuropogon -36
californicus 36, 37
refractus 36
sabinii 36
Plume-grass 258, 259
Poa 38, 41-45
amabilis 41
annua 41, 44
aquatica 34, 41
arachnifera 41, 44
bolanderi 41
caerulescens 74
capillaris 41
chinensis -. 41
compressa 41, 44
distans 38
douglasii 41
eragroslis 41, 46
fendleriana 41, 45
Page.
Poa flava 41, 76
howellii 41
kingii 30
macrantha 41
malabarica 41
nemoralis 128
nevadensis 41
palustris 44
pilosa 41
pratensis 41, 43
quinquefida 74
rigida 34
sand! >ergii 41, 45
scabrella 41, 42, 44
serotina 44
tenella 41
triflora 44
trivialis 44
weigeltiana 46
Poaceae 3, 5-6
Poatae (subfamily) 6-7
Pod corn 287
Podagrostis 127
(section of Agrostis) 127
Podopogon 160
Podosemum 145
capillaris 145
Poisonous grasses 36, 161, 269
Pollinia 270
gryllus 270
Polyanihrix 96
Polyodon 193
distichum 193
Polypogon 13, 137-139
littoralis 138
lutosus 138
maritimus 138
monspeliensis 138
Polyrhaphis 83
(section of Pappophorum) 83
Poranthera 269
Porcupine grass 160
Poverty grass 120, 165
Prairie hay 3
Proso millet 230
Psamma 123
littoralis 123
Ptychophyllum (section of Chae-
tochloa) 243
Puccinellia 36, 38
airoides 38
distans 38
festucaeformis... 38
INDEX.
303
Page.
Puccinellia gussonii 38
maritima 38
nuttalliana 38, 39
Purple-top 77
Quack-grass 87,88
Quaking grass 45, 46
Rabdockloa 172
domingensis 172
Rachilla 5
Range grasses. 4
Rarum 249
Ravenna grass 258
Reana luxurians 283
Reboulca 110
gracilis 110
Red. sprangle-top 173
Redfieldia 54-56
flcxuosa 54, 55
Redtop 4, 128, 129
Reed, giant 60, 62, 63
Reed-grass, wood 134
Reeds 63,64,65
Reimaria 225
acuta 225, 226
Candida 225, 226-227
elegans 226
Reimarochloa 18, 225
oligostachya 225, 226
Rhaphis 270,272-273
pauciflora 270, 272
trivialis 270
Rhapis. 270
Rhode Island bent 129
Rhodes grass 189
Rhombolytrum 74
rhomboidea 74
Ribbon grass 203
Rice 204,205
cut-grass 206, 207
Indian 209
tribe 204-206
wild 209,210
Rottboellia 278
compressa 278
dimidiata 218
fasciculata 278
incurvata 106
pannonica 106
repens 105
Rushes distinguished from grasses . 3-4
Rye 91,92
wild.. 95
Page.
Rye-grass 193
Australian. 103
English io3
Italian 103,104
perennial 193
Rytilix 278, 280
glandulosa 280
granularis 280
Saccaton 151
alkali 150, 152
Saccharine sorghums 267
Saccharum 255
floridulum 255
officinarum 255, 257
spicatum 255
Sacciolepis 236-237
striata 237
Saint Augustine grass 5, 219, 220
Salt-grass 58, 59
Sand-binding grasses 5, 123, 125
Sand bur 249
Savastana 199
hirta 199
Schedonnardus 179-180
paniculatus 180, 181
texanus 180
Schedonorus 28
Schellingia 169
tenera 169
Schizachyrium 260
condensation 260
Schleropelta 168
stolonifera 168
Schmidtia 132
subtilis 132
Schoenus aculeatus 153
Schrader's brome-grass 24
Sclerachne 135
arlcansana 135
pilosa 135
Selena elata 209
Scleropoa 34
rigida '. 34
Scleropogon 81
brevifolius 81, 82
Scolochloa 38
festucacea 38
Scribneria 91
bolanderi 91, 93
Sea marram 123
Seaside oats 60
Secale 91
304
INDEX.
Page.
Secale cereale 91-92
creticum 91
montanum 91
orientate 91
wllosum 91
Sedge distinguished from grasses. 3-4
Seneca grass 199
Sericrostis 145
Serrafalwis 24
Sesleria dactyloides 198, 199
Setaria 241, 243-245
glauca 243
italica 243-245
varietal key 244-245
wridis 241
Shallu 267
Sheath 5
Sheep's fescue 31
Short-grass 193
country 199
Siberian millet 245
Side-oats grama 193, 195
Sieglingia 74
albescens 74
decumbens 74, 118
Sitanion 94, 96
elymoidcs 96
hystrix 96, 97
jubatum 96
planifolium 96
Six-weeks grama 194
Sleepy grass 161
Slough-grass 181-182
Smut-grass 149, 150
Soil binders 4, 5
Soiling grasses 4
Sorghastrum 20, 269-270
avenaceum 269
elliottii 270
nutans 269, 270, 271
secundum 270
Sorghum 266-269
tribe 252-280
vulgare 266, 267
Sorgo 267
Sorgum 266
Sour-grass 215, 216
Spartina 182-185
alterniflora 183
glabra 183
pilosa'. 183
bakeri 183, 185
cynosuroid.es = 183
Page.
Spartina foliosa 183
gracilis 183
juncea 183
maritima 183
michauxiana 183, 184
patens 183, 185
juncea 185
schreberi 183
spartinae 183
stricta 183
tenacissima 5
Spear-grasses 158-161
Sphenopholis 12, 109, 110
obtusata 110-111
lobata 110
pallens 110
palustris ' 109
Spikelet : 5
Spirochloe 180
Spirotheros 273
Sporobolus 149-151
airoides 4, 150, 152
berteroanus 149, 150
black 151
cryptandrus 150, 151
elongatus 150
gracilis 150
indicus 150
interruptus 151
pulchellus 150
vaginaeflorus 150
virginicus 150
wrightii 150
Sprangle-top 172
red 173
Squirreltail grass 96
Stapfia 71
colusana 71
Stegosia 278
cochinchinensis 278
Stcinchisma 229
Stelephuras 140
Stenotaphrum 218-219
americanum 219
glabrum 218
secundatum 219, 220
Stink-grass 48
Stipa 158-161
avenacea 159, 160, 161
barbata 160
calamagrostis 127
capillaris 145
comata 161
INDEX.
305
Page.
Stipa juncea 159
lettermani 161
melanocarpa 273
minor 161
neo-mexicana 161
pennata 159
sericca 145
epartea 160,161
speciosa 161
tenuissima 161, 162
vaseyi. 161
viridula 161
Streptachne 163
pilosa 163
stipoidcs. 163
(section of Aristida) 163
Sudan grass 267
Sugar cane 255, 257
Sugar-producing grasses 4, 5
Sweet vernal grass 201, 202
Switch-grass 231
Syntherisma 215, 217-218
filiformis 218
ischaemum 218
praecox 215
sanguinalis 215, 217
serotina 215
villosa 215
Tabosa grass 169
Tall oat-grass 113, 114
Tares (of Scripture) 103, 209
Teosinte '... 283, 284
Terrcllia 93
Texas bluegrass 44
crowfoot 172
millet 232
Textile grasses 4, 5
Thurberia 135
Tickle grass 130
Timothy 4,140,141
mountain 140-141
tribe 121-165
Toothache grass 185, 186
Torresia 199, 201
alpina 201
macrophylla 201
odorata 199, 201
utriculata 199
Tosagris 145
agrostidea 145
Trachynotia 183
cynosuroides 183
97769 19 Bull. 772 20
Page.
Trachynotia juncea 183
polystachya 183
Trachypogon 20-275
montufari 275, 276
Tragus. 165
Triaena 193
racemosa 193
Triaihera 191
Tribes, sequence 2
Trichachne 215
insularis 215
Trichloris. 189, 191
blanchardiana 191
fasciculata 190*
mendocina 191, 192
pluriflora 190
Trichochloa 145,
expansa 145
purpurea 145
Trichodium 127
decumbens 127
laxiflorum 127
Tricholaena 241
micrantha 241
rosea 241,242
Trichoon 64
Tricuspis 74
caroliniana 74
novaeboracensis 74
Tridens 74
quinquefida 74
Triodia 73-76
albescens '. . 74, 76
avenacea 74, 75
drummondii 76
elongata 76
flava 74, 76, 77
mutica 76
nealleyi 75
pilosa 75
pulchella 74, 75, 76
pungens 74
stricta 76
trinerviglumis 74
Triplasis 76, 78
americana 76, IS
intermedia 78
purpurea 78, 79
Tripogon 172-174
bromoides 174
spicatus 174
Tripsaceae 2, 22, 280-28&
306
IXDEX.
Page.
Tripsacum, 280-281
dactyloides 281 282
fasciculatum 281
fioridanum 281
hermaphroditum 281
lemmoni 281
Trisetum 107-109
canescens 108
cernuum 108
hallii 109
interruptum 109
melicoideum .. 108
pennsylvanicum 109
pratense 108
spicatum 108, 109
wolfii 108
Trixiola 60
paniculata 60
Triticum 89
aestivum 89, 90
caninum 89
dicoccoides 89
dicoccum.... 89
hybemum . . 89
monoccocum 89
repens 89
sativum 89
spelta 89
turgidum 89
vulgare 89
Trixostis 163
Tufted hair-grass 116
Tunis grass 267
Turkish millet 245
Type species, definition 2
Typhoides 203
arundinacea 203
Uniola 6, 8, 58-60
gradlis 60
latifolia 60, 61
laxa 60
maritima 60
palmeri 60
paniculata 59, 60
spicata 58, 59
Urachnc 158
coerulescens 158
parviflora 158
xircscens 158
Uralepis 74, 76
aristulala 76
pilosa 74
purpurea 76
Page.
Umlepsis '. 74, 76
Uva grass 63
Valota 214, 215
hitchcockii 215
insularis 215, 21G
saccharata 215
Vanilla grass 199, 201
Vaseya 145
comata 145
Velvet bent 129
grass 118, 119
Vernal grass, sweet 201, 202
Vetch 3
Vetiver 263
Vctiveria zizanioides 263
Vilfa 127
tricholepis 151
Vulpia 28
myuros 28
(subgenus of Festuca) 30
Wasatchia 30
kingii 30
Water grass 227
Weingaertneria canescens 116
Western wheat-grass 87
Wheat 89,90
club 89
durum 89
grain hay 4
Wheat-grass 4,87
slender 87
western 87
Wildest-grass 120
oats ^ 111,112
rice 200, 210
rye 95
Willkommia 179
annua 179
sarmentosa 179
texana 179, 180
Windmill grass 189
Windsoria 74
ambigua 74
poaeformis 74
Wire-grass 44, 179
Witch-grass, old 232, 233
Wolftail 139
Wood reed-grass 134
Woolly foot 193
Xiphagrostis 255
floridula 255
japonica 255
Yard-grass 175
INDEX.
307
Page.
Yellow foxtail 343,244
Zea 22, 283, 287
mays 283, 285, 286
japonica 287
tunicata 287
Zeia 89
Zeocriton 98
Zerna 24
Zizania 3, 206, 209
aquatica 209
fluitans... 211
Page.
Zizania latifolia 209
microstachya 206
palustris 206, 209, 210
terrestris 209
Zizanieae 3, 18, 206-211
Zizanion 209
Zizaniopsis 206
miliacea 206, 208
Zoysia 165-166
pungens 166
Zoysieae 3, 15, 196
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