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THE ELEMENTS OF Structural Botany WITH SPECIAL REFERKNCE TO THE STUDY OV CANADIAlSr PLANTS, TO WHICH IS ADDED A. SELPJCTION OF" KXA]VII]SrA.TIOTsr PAPI^IRS. By H. B. SPOTTON, M.A.,F.L.S., HEAD MASTER OF BARRIR COLLEGIATE INSTITUTE, THIIU) EDITION. ILLUSTRATED BY THE AUTHOR. TORONTO: ' ' W. J. GAGE AND COMPANY, /-• 9K 20 1 Entered according to Act of Parliameut of Canada, In the Office of the Minister of Agriculture, by Adah MUiLLR & Co., in the year 1870. NoTB.— In explanation of the omission of Professor Masoun's name from the title page of the present edition, the Publishers desire to say that the original design of the authors was to prepare jointly a work on the Canadian Flora, Mr. Spotton to write and illustrate an introductory volume, and both parts, for the sake of uniformity, to bear the names of both authors. . Owing to Professor Macoun's engagement with the Dominion Government, the joint scheme was necessarily abandoned, and the whole work tthe second part of which is now in the press) will hence- orth be issued under Mr. Spotton's signature only. 7i / / '-■ PREFACE. The work, of which the present Httle volume forms the first part, has been undertaken, at the suggestion of several eminent educationists, to supply a palpable want. The works on Botany, many of them of great excellence, which have found their way into this country, have been prepared with reference to climates differing, in some cases, very widely from our own. They consequently contain accounts of many plants which are entirely foreign to Canada, thus obstructing the search for descriptions of those which happen to be common to our own and other countries ; and, on the other hand, many of our Canadian species are not men- tioned at rJl in some of the Classifications which have been in use. It is believed that the Classification which ia to form the second part of this work will be found to contain all the commonly occurring species of the Provinces whose floras it is designed to illustrate, with- out being burdened with those which are either ex- tremely rare, or which do not occur in Canada at all. The present Part is designed to teach the Elements of Structural Botany in accordance with a method which is believed to be more rational than that commonly adopted; and it will be found to supply all that is requisite for passing the examinations for Teachers' Oertifloates of all grades, as well as any others demand- ing an elementary knowledge of the subject. It contains familiar descriptions of common plants, illus- trating the chief variations in plant- structure, with a view to laying a foundation for the intelligent study of Systematic Botany with the aid of the second part; then follow a few lessons on Morphology ; and the IV PREFACE. Elements of Vegetable Histology are treated of in as simple and brief a manner as was thought to be con- sistent with the nature of the subject. The Schedules, the use of which is very strongly recommended, were devised by the late Professor Hens- low, of Cambridge University, to fix the attention of pupils upon the salient points of structure. They will be found invaluable to the teacher as tests of the accu- racy of his pupils' knowledge. The cost of striking off a few hundred blanks of each sort would be very trifling, and not worth considering in view of the resulting advantages. The wood-cuts are from drawings from living speci- mens, except in two or three instances where assistance wac derived from cuts of well-known excellence in standard works on Botany. It need hardly be said that the engravings are not in any sense intended to take the place of the living plants. They are designed chiefly to assist in the examination of the latter, and whilst it is hoped that they may be of service to those who may desire to read the book in the winter season, it is strongly urged upon teachers and students not to be saiisfied with them as long as the plants themselves are available. The works most frequently consulted in the prepar- ation of the text are those of Hooker, Gray, Bentley and Oliver. Finally, the Authors look for indulgence at the hands of their fellow-teachers, and will be glad to receive sug- gestions tending to increase the usefulness of the work, and to extend a taste for what must ever be regarded as one of the most refining as well as one of the mosfc practically useful of studies. September 1 1879. DESCRIPTION OF CUTS. Fig. 1. 2. 3. 4. 5. G. 7. 8. 9. 10. 11. 12. 13. U. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 2<'. 30. 31. H2. 33. 34. 35. 36, 37. 38. 39 40. 41. 42. 43. 14. (5. *6. PAge Fibrons rocrfr oi Batt?ercap 2 Magnified tip of rootlet 8 Stem of Buttercup 4 Badical leaf of same 6 Back view oi one of the flowers of Baiuo 6 Section of flower of same 7 Stamen of aame 7 Stamen diaQiiargingpoUen 7 Head of carpels ijf. IButtercup 7 A carpel magnified, and sfeowing ovule 7 Stigma of Buttercup, greatly magnified 8 Plan of stamen 8 Plan of carpel 9 Kipened carpel of Buttercup 10 Vertical section of same 10 Section of a seed, showing position of embryo 10 Pollen-grain developing its tube 12 Section of ovule, showing micropyle 12 Hepatica 14 Single flower of same, with bracts underneath 15 Head of carpels of 'iame 16 Single carpel 16 Marsh- Marigold 17 Head of carpels of same 18 Single carpel of same, split open 18 Shepherd's Purse 21 Flower of same 22 Tetradynamoufl stamens of same 22 Pistil of same 23 The same with on ei lobe removed to show seeds 23 Round-leaved Mallow 24 Section of flower of lame 24 Pit^til of same 24 Bing of carpels and persistent calyx of same ■■■... 24 Flower of Garden Pea 27 Front view of same 27 Diadelphous stamens of same 27 Pistil of same 27 Section of pistil 27 Flower of Great Willow-herb 29 Pistil of same bursting open 30 Section of same 30 Sprig of Sweet-Brier 32 Section of flower of same 32 Section showing carpels and hollow receptacle of same.. 33 Flower of Crab-Apple 88 n DESCRIPTION OF CTTTS. 47. Rpction of same 33 48. Crosa seotion of Crtib- Apple 34 49. Compound umbel of Water-Parsnip 35 60. Single flower of same 36 61. Section of pistil of same 35 62. Sfiction of flower of Dandelion 37 63. Single floret of Dandelion 37 64. Ligulate corolla of same with epipetalons stamens .... 37 65. Syngenesious stamens of Dandelion 38 66. Pappo»G seed of same 38 67. SiJigle flower of Catnip 39 68. Front view of same, showing didynamous stamens .... 39 69. Pistil of same H9 60. Carpels of same ? 40 61. Fi^rtile jSower of Cucumber 41 62. Sterile Slower of same , . 41 63. Sterile catkin of Willow 43 64. Fertile catkin of same 43 65. Singb) staminate flower of same 43 66. Singlo fertile flower of same 44 67. Pumpkin seed 45 68. Same showing cotyledons 45 69. Same showing plumule 45 70. Bean showing cotyledons and radicle 46 71. Same showing plumule 46 72. Dog's^tooth Violet 47 73. Pistil of same 49 74. Secti\^n of ovary 49 75. Trillium 60 76. Section of ovary of same 60 77. Net-veined leaf of same 60 78. Indian Turnip 61 79. Spathe of same 62 80. Fertile spadix of same 62 81. Sterile spadix of same 52 82. Spadix and spathe of Calla .... 64 83. Leaf of same 64 84. Perfect flower of same 66 85. Showy Orchis 56 86. Single flower of same 66 87 . Pollen mass.of same 67 88. Single flowed oi Timothy 68 89. Same opened to show parts 68 90. Section of a grain of Indian Corn 60 91. Embryo of same 60 92. Sfiction of embryo 60 99. Tap-root of Dandelion 63 94. Tap-root of Carrot 64 95. Fasrinled roots of Peony 64 96. Secoudary roots of Verbena 64 DESCRIPTION OF CUTS. VII 97. Tetidiil of Grape 66 98. Leaf-tendril of Pea 67 99. Tubers of Potato 67 100. lihizome 68 101. Section of Onion bulb 69 102. Lily bulb 69 103. Spine of Hawthorn 70 104. Prickles of Sweet-Brier 70 105. Wliorled leaves of Galium 71 106. Simple radiate-veined leaf of Mallow 71 107. Compound leaf of Clover 71 108. Maple leaf 72 109. Digitate leaf of Virginia creeper 73 110. Acicular leaves of Pine 74 111 — 134. Various forms of leaves 74 — 79 135. Form of a Corymb 83 136. Compound raceme 83 137. Form of Cyme 84 138. Petal of Garden Pink 8G 139. Tubular corolla of Honeysuckle 87 140. Funnel-shaped corolla of Bracted Bindweed 87 141. Salver-shaped corolla of Phlox 87 142. Labiate corolla of Turtle-head 87 143. Personate corolla of Toadflax 87 144. Stamen witii adnate anther 88 145. Stamen with innate anther 88 146. Stamen with versatile anther 88 147. Anther opening" along margin 89 148. Anther of Blue Cohosh with uplifting valves 89 149. Anther of a Heath with pores at the apex 89 150. 151. Ovary of Mignonette with seeds on the walls 91 152, 153. Ovary of Pink with seeds on a central column ... . 91 164. Cone 92 155. Single scale of same 92 156. One of the winged seeds of same 92 157. Fruit of Blackberry 94 158. Section of unripe Strawberry 94 159. Legume of Bean 95 160. Silicle of Garden Stock 96 161 . Pyxis of Portulaca 96 162. Samara of Maple 96 163. Loosely packed cells of the pith of Elder 99 164. Hair from leaf of a Petunia, showing cellular structure. 99 164. (a) Hair from leaf of Geranium 99 165. Tapering and overlapping cells of woody tissue 102 166. Dotted duct 103 167. Section of a young exogenous Btem 104 168. The same at a later period of growth 104 169. Section of an endogenous etem 105 170. Leaf-stomate , 107 CONTENTS CHAPTER I. PAGE Examination of a Buttercup 2 CHAPTER II. Functions of the Organs of the Flower 11 CHAPTER III. Examination of HepaticaandMarsh-Marigo^ ' -Resemblnncoa between their llowers and that of Buttev ^ 13 CHAPTER IV. Examination of other common plar ' with hyp f gy nous stamens — Shepherd's Purse — iiound-leaveil Mallow.... 21 CHAPTER V. Examination of common plants with pr rigynons stamens — Garden Pea — Great Willow-herb — Sweet- Brier— Crab- Apple 26 CHAPTER VI. Examination of a plant with epigynous stamens — Water- Parsnip 35 CHAPTER VII. Examination of common plants with epipetalous stamens — Dandelion — Catnip 36 CHAPTER VIII. Examination of plants with Monoecious and Dioecious flowers — Cucumber — Willow 40 CHAPTER IX. Characteristics possessed in common by all the plants previously examined — Structure of the seed in Dicoty- ledons 45 CHAP'^ER X. Examination of common plants continued — Dog's-tooth Violet — Trillium — Indian Turnip — Calla — Orchis — Timothy 47 Ha 1 1 \i I '^ CONTfiNtS. CHAPTER XT. PAGE Common characteristics of the plants just examined — Structure of the seed in Monocotyledons 69 CHAPTER XII. Morphology of Roots, Stems and Foliage-Leaves 62 CHAPTER XIII. Morphology of Flower-Leaves— The Calyx — The Corolla — The Stamens— The Pistil— The Fruit— The Seed— Ger- mination Bl CHAPTER XIV. On the minute structure of Plants — Exogenous and Endo- genous Stems — Food of Plants 98 CHAPTER XV. Classification of Plants according to the Natural System 109 The Herbarium 115 Index and Glossary 118 Examination Questions k 134 li. I I TABLE OF THE COMMON PLANTS EXAMINED, To. GETHER WITH THE FAMILIES TO WHICH THEV BELONG. Buttercup, Hepatica, Marsh- Marigold.CBOwrooT Family. Shepherd's Purse Cress Family. Eound-leavcd Mallow Mallow Family. Garden Pea Pulse Family. Great Willow-herb Evening-Primrose Family. Sweet-Brier, Crab-Apple Rose Family. Water-Parsnip Parsley Family. Dandelion Composite Family. Catnip Mint Family. Cucumber Gourd Family. Willow Willow Family. Dog's-tooth Violet, Trillium Lily Family. Indian Turnip, Calla Arum Family. Showy Orchis Orchis Family. Timothy Grass Family. . XI !-ir ih - if \ ii I 1 U t 8 THE ELEMENTS OP STRUCTURAL BOTANY 1. The study of Botany is commonly rendered unat- tractive to the beginner by the order in which the parts of the subject are presented to him. His patience be- comes exhausted by the long interval which must neces- sarily elapse before he is in a position to do any practical work for himself. In accordance with the usual plan, some months are spent in committing to memory a mass of terms descriptive of the various modifications which the organs of plants undergo ; and not until the student has mastered these, and perhaps been initiated into the mysteries of the fibro-vascular system, is he permitted to examine a plant as a whole. In this little work, we purpose, following the example of some recent writers, to reverse tin's order of things, and at the outset to put into the learner's hands some com- mon plants, and to lead him, by his own examination of these, to a knowledge of their various organs — to 2 ELEMENTS 01-' tjIi:U^iL'.vA .. LjIA.NV. cultivate, in shoio, not merely his memory, but also, and chiefly, his powers of observation. It is desirable that the beginner should provide him- self with a magnifying glass of moderate power for examining the more minute parts of specimens ; a sharp penknife for dissecting ; and a couple of fine needles, which he can himself insert in convenient handles, and which will be found of great service in separating delicate parts, and in impaling fine portions for examination with the aid of the lens. CHAPTEE I. ! I EXAMINATION OF A BUTTERCUP. 2. To begin with, there is no plant quite so suitable as our common Buttercup. This plant, which has conspicuous yellow flowers, may be found growing in almost every moist meadow. Having found one, take up the whole plant, loosening the soil a little, so as to obtain as much of the Root as possible. Wash away the earth adher- ing to the latter part, and then proceed to ex- amine your spec- imen. Begin" . ning with the Root, (Fig.l) the Fig. 1, first noticeable thing is that it is not of the same colour as the rest of Elements of structural botany. 8 the plant. It is nearly white. Then it is not of th\3 same foim as the part of the plant ahove ground. It is made up of a number of thread-like parts which spread out in all directions, and if you examine one of these threads through your magnifying glass, you will find that from its surface are given off many finer threads, called rootlets. These latter are of great im. portance to the plant ; it is largely by means of their tender extremities, and the parts adjacent to these, that it imbibes the nutritious fluids contained in the soil. Whilst you are looking at these delicate rootlets, you may perhaps wonder that they sliould be able to make their way through the soil, but. how they do this will be apparent to you if you lexamine th« tip of one of them with a microscope of considerable power. Fig. 2 repre- sents such a tip highly magnified. It is to be observed that the growth of the rootlet does not take place at the very extremity, but immediately behind it. The extreme tip consists of harder and firmer matter than that behind, and is in fact a sort of cap or thimble to protect the growing part underneath. As the rootlet grows, this little thimble is pushed on first through the crevices of the soil, and, as you may sup- pose, is soon worn away on the outside, but it is as rapidly renewed by the rootlet itself on the inside. Another difference between the root and the part above ground you will scarcely have failed to discover : the root has no leaves, nor has it any buds. Fig. 2. You may describe the root of the Buttercup asjibrous. BLEMfiTS OP STRtJCTt'RAL BOTANY. il I ; ii I ;■! il, l( Fig. 3 3. Let us now look at the Ltem. (Fig.3.) Itis upright, pretty firm, coloured green, and leaves spring from it at intervals. As there is scarce- ly any appearance of wood in it, we may describe it as herbaceous. At several points along the main stem branches are given off, and you will observe that immediately below the point from which every branch springs there is a leaf on the stem. The angl^ between the leaf and the stem, on the upper side.' is called the anil of the leaf (axilla, an armpit), and it is a rule to which there are scarcely any exceptions, that branches can only spring from the axils of leaves. The stem and all the branches of our plant termi- nate, at their upper extremi- ties, either in flowers or in flower-buds. ''.^tU. 4. Let us now consider the Leaves. A glance will show you that the leaves of this plant are not all alike. Those at the lower end of the stem have long stalks, (Fig. 4) which we shall henceforward speak of as jj^tioles. Those a little higher up have petioles too, but they are not ii! ELEMENTS OF STRUCTURAL BOTaNV. quite so long as tlie lower ones, and the highest leaves have no petioles at all. Tlicy appear to be sitting on the stem, and hence are said to be sessile. The lowest leaves oi all, as the;y seem to spring from the root, may b<. described as radical^ whilst the higher ones may be called canine (cattlisy a stem). The broad i)art of a leaf is its hh((!e. In the plant we are now examining, the blades of the leaves are almost divided into distinct pieces, wiiich are called lobes, and each of these again is more or less deeply cut. Both petioles and blades of our leaves are covered with minute hairs, and so are said to be hairy. Hold up one of the leaves to the light, and you will observe that the veins run through it in all directions, forming a sort of net-work. The leaves are therefore net-veined. The points along the stem from which the leaves arise are called nodes, and the portions of stem between the nodes are called internodes. 5. Let us next examine the Flowers. Each flower in our plant is at the end either of the stem or of a branch of the stem. The upper portions of the stem and its branches, upon which the flowers are i-aised, are called !he ])edwicles of the flowers. Take now a flower which has just openod. Beginning at the outside, you will find live little spreading leaves, somewhat yellowisii in colour. Each of these is called a sejiat, and the five together form the calyx of the ^1 m .-. Hit ELEMENTS OF STEUCTURAr. UOTAnY. flower. If you look at a flower which is a little older, you will probably not find any sejmls. They will have fallen off, and for this reason they are said to be decidu- ous. So, in like manner, the leaves of most of our trees are deciduous, because they fall at the approach of winter. You will find that you can pull off the sepals one a"' n time, without disturbing those that remain. This shows that they are not connected together. They are therefore said to he free, and the calyx is described as pohjsepalous. Inside the circle of sepals there is another circle oi leaves, usually five in number, biiglit yellow in colour, and much larger than the sepals. Each of them is called a peUd, and the five together form the corolla of the flower. Observe carefully that each petal is not in- serted in front of a sepal, but in front of the space be- tween two sepals. The i)etals can be removed one at a time like the sepals. They, too, are free, and the cor- olla is poli/pet(d<)us. If you compare the 2)etals with one another, you will see that they are, as nearly as possi- ble, alike in size and shape. The corolla is therefore regular, 6. We have now examined, minutely enough for our present purpose, the calyx and corolla. Though their divisions are not coloured green, like the ordinary leaves of the plant, still, from their general form, you will have no difficulty in accepting the statement that the sepals and petals are in reality leaves. It will not be quite so apparent that the parts of the flower which still remain are also only modifications of the same structure. But there is good evidence that this is the case. Let us, ELEMENTS OF STBUOTURAL BOTANY. ;e SO Lain But It us, i a* :1 i\ however, examine these parts that re- main. There is first a large number of little yellow bodies, each at the top of a little thread-like stalk. Each of these Fig. 6. bodies, with its stalk, is called a stamen. The little body itself is the anther, and the stalk is its filament. Your magnifying glass will show you that each anther consists of two oblong sacs, united length- wise, the filament being a continuation of the line of union. (Fig. 7.) /tV ./flV:: If yo^ lo<^^ ^^ ^ stamen of a flower which III JijI b has been open some time, you will find that vll 'W^ •' gagii anther-cell has split open along its outer edge, and has thus allowed a fine yellowish dust to escape from it. (Fig. 8.) This dust IS called pollen. A powerful Fig 8 magnifier will show this pollen to consist of grains having a distinct form. As the stamens are many m number, and free from each other, they are said to be poljandrom. 7. On removing the stamens there is still left a little raised mass, (Fig. 9) which with the aid of your needle you will be able to separate into a number of distinct pieces, all exactly alike, and looking something hke unripe seeds. Fig. 10 shows one of them very much magnified, and cut through lengthwise. These little bodies, taken « separately, are called carpels. Taken together, they form the pistil. They are hollow, and each of them contains, as the figure shows, a little grain-like substance attached to the lower end of its cavity. This substance, in its present condition, is jOie ovule, and later un becomes the seed. Fig- 7. Fig. 9. Fig. 10. sa 8 ELEMENTS OF STRUC'IURAL BOTANY. f . Fig. 11. You will notice that the carpel ends, at the top, in a little bent point, and that the convex edge is more or less rough and moist, so that in flowers whose anthers have burst open, a quan- tity of pollen will be found sticking there. This rough upper part of the carpel is called the stiijrnn. Fig. 11 shows a stigma greatly magnified. In many plants the stigma is raised on a stalk above the ovary. Such a stalk is called a style. In the Buttercup the style is so short as to be almost suppressed. When the style is entirely absent the stigma is said to be sessile. The hollow part of the carpel is the ovary. In our plant the pistil is not connected in any way with the calyx, and is consequently said to be free or superior, and, as the carpels are not united together, the x)istil is said to be iqwcarpous. 8. Remove now all the carpels, and there remains nothing but the swollen top of the peduncle. This swollen top is the receptacle of the flower. To it. in the case of the Buttercup, all four parts, calyx, corolla, stamens, and pistil, are attached. When a flower has all four of these parts it is said to be complete. 9. Let us now return to our statement that the struc- ture of stamens and pistils is only a modi- fication of leaf- structure generally. The stamen looks less like a leaf than any other part of the flower. Fig. 12 will, however, serve to show you the plan upon which the botanist considers a stamen to be formed. The anther corresponds to the leaf-blade, and the filament to the petiole. The two cells of the anther correspond to the two Fig. 12 I ELEMENTS OP STRUCTURAL BOTANY, ), in a ore or Lowers quan- there. [•pel is stigma its the 5uch a ! is so tyle is . The ay way free or gether, emains This in the orolla, er has halves of the leaf, and tlie ceils burst open along what answers to the margin of the leaf. 10. In the case of apocarpous pistila, as that of the Buttercup, the botanist considers each carpel to be formed by a leaf- blade doubled lengthwise until the edges meet and unite, thus forming the ovary. Fig. 13 •svill make this clear. 11. There are many facts which support this theory ao to the nature of the different parts of the flower. Suffice it to mention here, that in the white Water- Lily, in which there are several circles of sepals and petals, it is difficult to say where the sepals end and the petals begin, on account of the gradual change from one set to the other. And Fig. 13. ^^^ ^^^y ^^ there a gradual transition from se- pals to petals, but there is likewise a similar transition from petals to stamens, some parts occurring, which are neither altogether petals, nor altogether stamens, but a mixture of botli, being imperfect petals with imperfect anthers at their summits. We can thus trace ordinary leaf-forms, by gradual changes, to stamens. "We shall, then, distinguish the leaves of plants as foliage-leaves, and flower-leaves, giving the latter name exclusively to the parts which make up the flower, and the former to the ordinary leaves which grow upon the stem and its branches. 12. You are now to try and procure a Buttercup whose flowers, or some of them, have withered away, leaving only the head of carpels on the receptacle. The carpels will have swollen considerably, and will now show themselves much more distinctly than in the la ELEMENTS OF STRUCTURAL BOTANY. flower which we have been exam- ^^ inmg. This is owing to the growth j^k of the ovules, whicli have now s:---" become seeds. liemove one of Fig. 11. Fig. 15. the carpels, and carefully cut it through the middle lengthwise. You will find that the seed almost entirely fills the cavity. (Figs. 1-4 and 15.) This seed consists mainly of a hard substance called albunh'H, enclosed in a thin covering. At (0 / the lower end of the albumen is situated a very Fig iG. small body, which is the emhnjo. It is this which develops into a new plant when the seed germi- nates. 13. We have seen then that our plant consists of several parts : (1). The Root. This penetrates the soil, avoiding the light. It is nearly white, is made up of fibres, from which numbers of much finer fibres are given off, and is entirely destitute of buds and leaves. (2). The Stem. This grows upward, is coloured, bears foliage-leaves at intervals, gives ofi" branches from the axils of these, and bears flowers at its upper end. (3). The Leaves. These are of two sorts : Fo/^/^e- Icaves and Flower-leaves, The former are sub-divided into radical and cauline, and the latter make up the flower, the parts of which are four in number, viz. ; calyx, corolla, stamens, and pistil. It is of great importance that you should make your- selves thoroughly familiar with the different parts of the plant, .as just described, before going further, and to that end it will be desirable for you to review the pre- sent chapter carefully, giving special attention to those 11 ; ELEMENTS OF STniJCTURAL JJOTANY. IJ parts which were not perfectly [ilaiii to you on your first reading. In the next chapter, we shall give a very hricf ac- count of the 7/.SV.S of the tUfferent parts of the flower. If fo\jncl too djfticult, the study of it may be deferred until further progress has been made in plant examination. CHAPTER 11. FUNCTIONS OF THE ORGANS OF TTTE FLOWER. 14. The chief use of the calj^ and corolla, or flor-u efrvdoi,js, as they arc collectively called, is to protirt the other jxniti of the flower. Tliey enclose 'the stamens and pistil in the bud, and they usually wither away and dis- appear shortly after the anthers have shed their pollen, that is, as we shall presently see, as soon as their ser- vices as protectors are no longer required. 15. TJie corollas of flowers are usually bright-colour- ed, and frequently sweet-scented. There is little doubt that theso qualities serve to attract insects, which, in search of honey, visit blossom after blossom, and, bring- ing their hairy limbs and bodies into contact with the open cells of the anthers, detach and carry away quan- tities of pollen, some of which is sure to be rubbed off upon the stigmas of other flower: of the same kind, subsequently visited. . 16. The essential part of the stamen is the anther, and the purpose of this organ is to produce the pollen, which, as you have already learned, consists of minute grainSf having a definite structure. These little grains are usually alike in plants of the same kind. They are I i 12 ELEMENTS OF STRUCTURAL BOTANY* furnished with two coats, the inner one extremely thin, and the outer one much thicker by comparison. The interior of the pollen-grain is filled with liquid matter. When a pollen-grain falls upon the moist stigma it begins to f/row in a curious manner. (Fig. 17). The inner coat i)ushes its way through the outer one, at some weak point in the latter, thus forming the beginning of a slender tube. This slowly pene- trates the stigma, and then extends itself down- Fig. 17. wards through the style, until it comes to the cavity of the ovary. The liquid contents of the pollen- grain are carried down through this tu"be, which remains closed at its lower end, and the body of the grain on the stigma withers away. The ovary contains an ovule, which is attached by one end to the wall of the ovary. The ovule consists of a kernel, called the nucleus^ which is usually surrounded by two coats, through both of which there is a minute opening to the nucleus. This opening is called the ndrropyle, and is always to be Fig. 38. found at that end of the ovule which is not attached to the ovary. (Fig. 18, m.) About the time the anthers discharge their pollen, a little cavity, called the emhr^/o-snc, appears inside the nucleus, near the micropyle. The pollen-tube, with its liquid contents, enters the ovary, passes through the micropyle, penetrates the nucleus, and attaches itself to the outer surface of the embryo-sac. Presently the tube becomes empty, and then withers away, and, in the meanwhile, a minute body, which in time develoi^es into the embryo, makes its appearance in the embryo- sac, and from that time the ovule may i)roperly be called a seed. ELEMENTS OF STRUCTURAL BOTANY. 13 17. In order that ovules may become seeds, it is always essential that they should be fertilized in the manner just described. If we prevent pollen from reaching the stigma — by destroying the stamens, for instance — the ovules simply shrivel up and come to nothing. Now it is the business of the flower to produce seed, and we have seen that the production of seed depends mainly upon the stamens and the pistil. These organs may consequently be called the essential organs of he flower. As the calyx and corolla do not play any direct part in the production of seed, but only protect the essential organs, and perhaps attract insects, we can understand how it is that they, as a rule, disappear early. Tl^eir work is done when fertilization has been accomplished. Having noticed thus briefly ine part played by each set of floral organs, we shall now proceed to the exami- nation of two other plants, with a view to comparing their structure with that of the Buttercup. CHAPTER III. EXAMINATION OF HEPATICA AND MARSH-MARIGOLD — RESEM- BLANCES BETWEEN THEIR FLOWERS AND THAT OF BUTTERCUP. in 18. Hepatica. You may procure specimens of the Hepatica almost anywhere in rich dry woods, but you will not find it in flower except in spring and early summer. Ijfc is very desirable that you should have the vlnn*; itself, but for those who are unable to obtaiu 14 ELEMENTS OF STRUCTUKAL BOTANY. Hi 411 r 1 i specimens, the annexed engravings may serve as a bubstitute. Beginning then at the root of our new plant, you see that it does not differ in any great measure from tliat of tlio Buttercup. It may in hke manner be described iiHjihroiis. Fife'. 19. The next point is the stem. You will remember tliat in the Buttercup the stem is that part of the plant from which the leaves spring. Examining our Hepa- tica in the light of this fact, and following the petioles of the leaves down to their insertion, we find that they and the roots appear to spring from the same place — that there is, apparently, no stem. Plants of this kind are therefore called acaulescent, that is, stemkss, but it tQUst be carefully borne in mind that the absence of the ^s ELEMENTS OF STRUCTURAL BOTAXY. 16 J stem is only apparent. In reality there is a stem, but it is so short as to be almost inrlistinguishable. The leaves of the Hepatica are of course all radical. They will also be found to be net-veined. 19. The Flowers of the Hepatica are all upon loup peduncles, which, like the leaves, appear to spring from the root. Naked peduncles of this kind, rising from the ground or near it, are called scapes. The flower- stalks of the Tulip and the Dandelion furnish other familiar examples. Let us now proceed to examine the flower itself. Just beneath the coloured leaves there are three leaf- lets, which you will be almost certain to regard, at first sight, as sepals, forming a calyx. It "v^ll not be diffi- cult, however, to convince you that fliis conclusion would be incorrect. If, with the aid of your needle, you turn back these leaflots, you will readily discover, between them and the coloured portion of the flower, a renj sli'ort hit of stem (Fig. 20), the upper end of which is the recejUacle. As these leaflets, then, are on the peduncle, below the receptacle, they cannot be sepals. They are simply small foliage leaves, to which, as they are found beside the flower, the name bracts is given. Our flower, then, is apparently without a calyx, and in this respect is different from the Buttercup. The whole four parts of the flower not being present, it is said to be incomplete. 20. It may be explained nere thai there is an under- standing among botanists, that if the calyx and corolla are not both present it is always the corolla which is wanting, and so it happens that the coloured part of the flower under consideration, though resembling a Fig. 20. ill 16 ELEMENTS OF STRUCTURAL BOTANY. ii n I! i'\ corolla, must be regarded as a calyx, and the flower it- self, therefore, as apetalons. 21. Bemove now these coloured sepals, and what is left of the flower very much res.embles what was left of our Buttei'cup, after the removal of the calyx and cor- olla. The stamens are very numerous, and are inserted on the receptacle. The carpels are also numerous, (Fig. 21) are inserted ^ij^^ on the recex)tacle, and are free from each other [apocarpous). And if you Fig. 21. Fig. 22. examine one of the carpels (Fig. 22) you will find that it contains a single ovule. The flower, in short, so much rpsembles that of the Butter- cup that yea will be prepared to learn that the two be- long to the same Order or Family of plants, and you will do Y/ell to observe and remember such resemblances as liave just been brought to your notice, when you set out to examine plants for yourselves, because it is only in this way, and by slow steps, that you can acquire a satisfactory knowledge of the reasons which lie at the inundation of the classification of plants. 22. Marsh- Marigold. This plant grows in wet places almost everywhere, and is in flower in early summer. Note the entire aosence of nairs on the surface of me plant. It is therefore glabrous. The root, like that of the Buttercup anu of ihe He- patica, is fibrous. The stem is hollow and furrowed. The foliage-leaves are of two kinds, as in the Butter- cup. The radical leaves spring from the base of the item, whilst the higher ones are cauline. The leaves ELEMENTS OF STRUCTURAL BOTANY. 17 Fig. 23. are not lobed, as in tlic other two plants, but are in- dented on the edge. They are also net-veined. 23. Coming to the flower (Fig. 23) we find a circle, or whorl, of bright yellow leaves, looiiing a good deal like the petals of the Buttercup, but you will look in vain for the corre- sponding sepals. In this case there is no whorl of bracts to mislead you. Are we to say, then, that there is no calyx ? If we adhere to the under- standing mentioned when describin \ the Hepatica, we must suppose tho corolla to be wanting, and then the bright yellow leaves of our plant will be the sepals, and will together constitute the calyx. As to the number of the sepals, you will find, as in the Hepatica, some variation. Whilst the normal number is five, some flowers will be found to have as many as nine. 24. The stamens are next to be examined, but you should first satisfy yourselves as to whether the calyx is polysepalous or otherwise, and whether it is free from the other fioral leaves or not. If vour examination be properly made, it will show you that the calyx is free and polysepalous. The stamens are very much like those of the Butter- cup and Hepatica. They are numerous, they have both r.ntliers and filaments, and they shed their pollen throug^h slits on the outer edges of the anthers. They are all separate from each other (polyandrous) and are all inserted on the receptacle. On this latter accoujit they arc said to be hjpogyiwKs, I \ ^ IS ELEMENTS OF STRUCTURAL BOTANY. I In! I -p U 25. Remove the stamens, and you have left, as be- fore, a head of carpels (Fig. 24). Examine one : there is the lower broad part, which you recognize as the ovary, the very short style, and the sticky stigma. To all appearance the carpels are pretty much the same as those of the two plants already examined. It will not do, how- Fi,". 24 ever, to trust altogether to appearances in this case. Cut open a carpel and you find that, in- stead of a single ovule at the bottom of the ovary, there are several ovules in a row along that edge of the ovary which is turned towards the centre of the flower. The ovary is, in fact, a pod, and, when the seer's ripen, splits open along its inner edge. If you /'i?' /f.'Kl can find one which has split in this way, you can 1||| hardly fail to be struck with the resemblance p. 25 which it bears to a common leaf. (Fig. 25.) On the whole the resemblance between the structure of the Marsh-marigold and that of the Hepatica and Buttercup is sufficiently great to justify us in placing it in the same family with them. 26. Having now made yourselves familiar with the different parts of these three plants, you are to write out a tabular description of them according to the fol- lowing form ; and, in like manner, whenever you ex- amine a new plant, do not consider your work done until you have written out such a description of it. In the form the term cohesion relates to the union of like parts ; for example, of sepals with sepals, or petals with petals ; while the term adhesion relates to the union of unlike parts ; for example, of stamens with corolla, or ovary with calyx. Neither cohesion nor ad- hesion takes place in any of the three flowers we have 11 ELEMENTS OF STRUCTURAL BOTANY. 19 examined, and accordingly, under these headings in our schedule we write down the terms polysepalous, poly- petalous, &c., to indicate this fact. The symbol oo means " indefinite," or *' numerous," and may be used when the parts of any organ exceed ten in number. BUTTERCUP. onOANORPART OF FliOWKR. NO. COHESION. ADHESION. RKMARKS. Calyx. Sepals. 5 Polysepalous. Inferior. Corolla. Petals. 5 Polypetalous. Regular, 1 Stamens. Filaments. Anthers. oc Polyandrous. H>T)Ogyuous. Pistil. Carpels. Ovary. oc Apocarpous. Svaperior. ■ I 20 ELEMENTS OF STllUCIUiU^ BOTANY. IIEPATICA. ■I i ii '''' :m. if ■li J. OnOAN. NO. COHESION. ADHESION. KKMARKS. Calyx. Sepals. 7-12 Polysepalous. Inferior. Coloured like a Corolla. Calyx. Petals. "Wanting. Stamens. Filaments. Anthers. oc Polj'androus. Hypogynous. Pistil. Carpels. Ovary. a Aoocarpous. Superior. • MARSH-MARIGOLD. ORGAN. NO. COHESION. ADHESION. IlEMARKS 1 Calyx. 1 i ,' epals. 5-9 Polysepalous. Inferior. Coloured like a Corolla. Corolla . Petals. Wa ting. Stamens. Filaments. Anthers. oc Polyandroua. Hypogynous. - Pistil. Carpels. Ovary. CK Apocarpous - Superior. Carpels contain several seeds. '^s ELEMENTS OP STRUCTURAL BOTANY. 21 ii^MARKS. uredlikea oroUa. ting. HARKS red like a rolla. ng. s contain il seeds. I CHAPTER IV. I EXAMINATION OF OTHER COMMON PLANTS WITH HYPOGYNOUS STAMENS, shepherd's PURSE. ROUND-LEAVED MALLOW. f 27. We shall now proceed to examine some plants. ^ the flowers of which exhibit, in their structure, impor- j taut variations from tlie Buttercup, Hepatica, and ; ^larsh-^Mi^rigold. 3? ig 2«, 22 ^:lements of structural botany. I'- 1 Hi i § w. ; hepherd's Purse. This plant, (Fig. 20). is on i of tlie commonest of weeds. As in tlie Buttercup, the foliage-leaves are of two kinds, radical and cauline, tlio former being in a cluster around tlie base of the stem. The cauline leaves are all sessile, and each of them, at its base, projects backward on each side of the stem, so that the leaf somewhat resembles the head of an arrow. Such leaves are, in fact, said to be sa(/itlate, or arrow- shaped. The flowers grow in a cluster at the top of the stem, and, as the season advances, the peduncle gradu- ally elongates, until, at the close of the summer, it fv^rms perhaps half of the entire length of the stem. You will observe, in this plant, that each separate flower is raised on a little stalk of its own. Each of these little stalks is a pedicel, and when pedicels are present, the term peduncle is a2)plied to the portion of stem which supports the whole cluster. 28. The flowers, (Fig. 27), are rather small, and so will require more than ordinary care in their examination. The calyx is polysepalou.«, and of four sepals. The corolla is polypetaious, Fi^'. 27. and of four petals. The stamens, (Fig. 28), are six in number, and if you examine them atten- tively, you will see that two of them are shorter than the other four. The stamens are conse- quently said to be tetradynamous. But if there Fig. 28. liad been only four stamens, in two sets of two each, they would Iwive been called didynamous. The stamens are inserted on the receptacle (hypogynous). The pistil is se^Darate from the other parts of the flower (superior). - 29. To examine the ovary, it will be better to select pi ripening pistil from the lower part of the pedni^c' , i .:ij r,LEMENT9 OF STRUCTURAL l30i«N'Y. ^a )). is 01) 1 roup, tho iline, the the stem, them, at stem, so in arrow. )r arrow- top of the le gradu- mmer, it the stem, separate Each of licels are )ortion of ler small, y care iu sepaloufs, petalous, 28), are ^m atten- pe shorter re conse- if there Is of two Ifis. The Igynous). be flower to select [etlii^^c' , It is a flat body, shaped something like a heart, (Fig 29) and having the short stylo in the notch. A ridge divides it lengthwise on each side. Carefully cut or pull away the lobes, and this ridge will remain, presenting now the appearance of a nar- ^ ^^ row loop, with a very thin membranous W \i« partition stretched across it. Around the edge, on both sides of the partition, seeds are suspended from slender stalks. (Fig. 30). There are, then, two carpels Fig. 29. Fig.ao wn'tcd tot/ether, and the pistil is, therefore, si/ncarpoiis. The pccuHar pistil of this flower should be carefully noticed, as it is the leading character of a whole group of plants. When you meet with such a pistil, you may be pretty certain that the plant to which it belongs is a member of the Cress or Crucifer family, so called from the four petals sometimes spreading out like the arms of a cross. We shall find, however, that there are cross- shaped corollas belonging to plants of other groups. SHEPHERD'S PURSE. OnoAN. No. 1 Cohesion. Adhi;s:ox. i 11. jiakks. Calyx. Sepals. 4 Polyscpalous. 1 Inferior. Corolla. Petals. 4 Polypetalous. Hypogynous. Stamens, Filaments. Anthers. 6 Tetrndyna- nious. Hypogynous. 1 Pistil. Carpel 1 Ovary, 2 Syncarpous. • Superior. The two cells of the ovary se- paruteil by a thi I purtiticn. ^ 24 ELEMENTS OP STRUCTURAL BOTANY. ! i\ '■ iiri':; ii m 1 1 f i 1:1,1 'il! \'""' ;!' , i.!l PI ,J!I1! "" •'1 ISIH' 30. Mallow. Tlie roniul-lcaved Mallow (Fig. 31) grows a 1 o 11 K every way sido^ and is a very common weed i n cultivated grounds. Pro- cure, if possible*- a plant which lias ripened its seeds, as well as one in flower. The root of this plant is. of a different Idnd from those of the three plants first examined. It consists of a stout tapering part, descending deep into the soil, from the surface of which fibres are given off ircegularly. A stout root of this kind is called a tap-root. The Carrot is another example. 31. The leaves are long-petiolod, net- veined and in- dented on the edges. On each side of the petiole, at its junction with the ^-t^m, you will observe a little leaf- like attachment, to which the name stipule is given. The presence or absence of stipules is a point of some importance in plant-structure, and you will do well to notice it in your examinations. You have now made yourselves acquainted with all the parts that any leaf lias, viz., hlade, petiole nnd stipules. LlK-1 , 1 ftLEMENTS OP STRUCTURAL BOTANY. 25 ' (Fig. ,<]1) WH aloii^' ^ way sido, is a verv lion weed ; cultivated ids. Vvo. if possiblct Hit wljicli L'iponcd its . as well as in flower, oot of this is. of a 5nt Ivind ;liofioof the plants first ncd. It is ts of a tapering surface of ut root of s another i and in- etiole, at ittle leaf- is given, of some > well to )w made any leaf 82. Coming to the flower, olserve fust that the parts of the calyx are not entirely separate, as in the flowers you have already examined. For about half their length they are united together so as to form a cup. The upper half of each sepal, however, is perfectly dis- tinct, and forms a tooth of the calyx ; and the fact that there are five of these teeth shows us unmistakably that the calyx is made up of five sepals. We therefore speak of it as a (jamosepalous calyx, to indicate that the parts of it are coherent. As the calyx does not fall away when the other parts of the flower disappear, it is said to be persistent. Fig. dl, a, shows a persistent calyx. 83. At the base of the calyx there are three minute leaf-like teeth, looking almost like an outer calyx. A circle of bracts of this kind is called an uivolucre. The three bracts under the flower of the Hepatiea also con- stitute an involucre. As the bracts in the Mallow grow on the calyx, some botanists speak of them as an epi- calyx. The corolla consists of five petals, separate fi om each other, but united with the stamens at their base. 34. The stamens are nuni ;oijs. and as their fihi- ments are united to form a tube they are said to be monmlelphous. This tube springs from the receptacle, and the stamens are therefore hypogynons. Fig. 32 will help you to an understanding of the relation between the petals and stamens. Having removed the petals, split the tube of the stamens with the point of your needle. A little care will then enable you to remove the stamens without in- juring the pistil. The latter organ will then be found to consist of a ring of coherent carpels, a rather stout 26 ELEMENTS OF STRUCTURAL BOT.\NY. )!! ■'t| iilnii style, and numerous long stigmas. (Fig. 33.) If you take the trouble to count the carpels and the stigmas, vou "will find the numbers to correspond. As the seeds 1 ipen the carpels separate from each other. (Fig. 34.) MALLOW. Okgan. No. 5 Cohesion. Adhesion. Remarks. Calyx. Scnals. Giiinosepsa- lous. Inferior. Three brticts growin}^ on the Lilly X. Corolla Petals. 5 Polypetalous. Hypogynous. Stamens. Filaments. An titers. X X Monadelplious United in a ring. One-celled. Hypogynous. • Pistil. Carpels. Ovary. Syncarpous. Superior. Carpjls us iii ny as the stigmrs. CHAPTER V. EXAMINATION OF COMMON PLANTS WITH PERIGYNOUS STAMENS GARDEN PEA. GREAT WILLOW-HERB, SWEET-BRIER, CRAB -APPLE. 35. Garden Pea. In the flower of this plant, the calyx is constructed on the same plan as in the Mallow. There are five sepals, coherent below, and spreading out into distinct teeth above '^Fig. 35). The calyx is there- fore gamosepalous. Examine next the form of the corolla (Fig. V>(j). One difference between th's corolla and those of tliM previous plants will strike you at once. In tlio fl >v, jj :; ELEMENTS 07 STRUCTURAL BOiANY. 27 rig. 36. Fi;'. 38. of the latter you will re- member that each i^etal was precisely like its fellows in size aud shape, aud we there- fore spoke of the coroKa f fisrq/idd)'. In the Pea, ft on tlie other hand, one of the petals is ]fivac, broad, and open, whil t two smaller ones, in the front of the flower, are united into a kind of hood. We shall speak of this corolla, then, and all others in which the petals are unlike each other in size or shape, as irm/iilar. As the Pea blossom bears some resemblance to a butterfly, it is said to be papiliunuceoiis. 3G. Remove now the calyx-teetli and the petals being very careful not to injure the stamens and thf pistil, enveloped by those two which form the hood Count the stamens, and notice their form (Fig. 37) You will find ten, one by itself, and the other nine with the lower halves of their filaments joined together, or coherent. "When stamens occur in this way, in two distinct groups, they are said to be diadcljihoits ; if in three groups, tliey would be tr'mdelpliom ; if in several groups, pohfaddphous. In the Mallow, you will remem- ber, they are united into erne grouji, and therefore we described thef/i as monadclplHjuH. You will perhaps be a little puzzled in trying to determine to what part ol the flower t' e stamens are attached. If you look closely, however, you will see that the attachment, or insertion, in not quite the same PvS in the Buttercup and the otlu/r ilowers examinp'^, Ik 28 ELEMENTS OF STRUCTURAL BOTANY. Ill tlie present instance, tliey are inserted upon the lower pait of the calyx, and so they are described as ]>fn(/y}ious, a term meaning ** around the pistil." 37. But the pistil (Figs. 38, 39) is not attached to the calyx. It is free, or superior. If you cut the ovary across, you will observe there is but one cell, and if you examine the stigma, yOu will find that it shows no sign of division. You may therefore be certain that the pistil is a single carpel. You are now j)repared to fill up the schedule descrip- five of this flower. GARDEN PEA. Organ. No. Cohesion. Adhesion. Remarks. Calyx Sejmls. 5 Gamosepalous. lufeiior. , Corolla. Petals. 5 rolvpetalous. Irregular. Hvjiogynous. Stamens. Filaments. nthers. 10 Diadelphous. Perigynous. Pistil. Carpels. Ovary. 1 Apocarpous. Superior 38. The beginner will be very likely to think, from its appearance, that the largest of the petals is made up of two coherent ones, but the following considera- tions show clearly that this is not the case. In the LuLLercup, and other flowers in which the number of ^epals and petals is the name, the petals do not stand "■"""""'frlliilll HSLfiMENTS OF STRUCTURAL BOTANY. ^0 ipon the sribed as »» ached to he ovary id if you 5 no sign that the descrip- BIARKS. — I k, from is made Qsidera- In the nber of :>t stand before the sepals, but before the spaces between them. In the Pea- blossom this rule holds good if the large petal is considered as one, but not otherwise. Again, the veining of this petal is similar to that of a common leaf, there being a central rib from which the veins spring on each side ; and lastly, there are some flowers of the Pea kind — Cassia, for example — in which this particular petal is of nearly the same size and shape as the other four. 39. Great Willow-herb. This plant is extremely common in low grounds and newly cleared laud, and you may easily recognize it by its tall stem and bright purple flowers. Observe the position of the flowers. In the three plants first examined we found the flowers at the end of the stem. In the Willow-herb, as in the Mallow, they spring from the sides of the stem, and iuimedi- ately be^ow the point from which each flower springs you will find a small leaf or bract (Fig. 40.) Flowers which arise from the axils of bracts are said to 1)C axiUary^ whilst those which are at the ends of stems are called ter- minal, and you may remember t'lat flov/ers can only be produced iu the axils of leaves and at the ends of stems and branches. 40. Coming to the flower itself, direct your attention, first of all, to the position of the ovary. You will find it apparently under the flower, in the form of a tube tinged with purple. It is not in reality under the flower, because its purplish covering is the calyx, or Fig. 40. H .-r.'.'V".' . *afe-.T I j ■ |ii|::i 1^0 ELEMENTS OF STRUOTlTR-\T, BOTANY. lilt!' more accurately the caly.v-tuhp, which adheres to the whole surface of the ovary, and expands above into four lonj^ teeth. The ovary therefore is inferior, and the calyx of course superior, in this flower. As the sepals unite below to form the tube the calyx is gam- osepalous. The corolla consists of four petals, free from each other, and is consequently polypetalous. It is also regular, the petals being alike in size and shape. Each petal is narrowed at the base into what is called the daw of the petal, the broad part, as in the ordinary foliagc-1^ 'if, being the blade. The si-d 5 are eight in number (octandrous), four short and ii. ir long, and are attached to the calyx (perigynous). 41- The pistil has its three parts, ovary, style, and stigma, very distinctly marked. The stigma consists of four long lobes, which curl outwards after the flower opens. The style is long and slender. The examina- tion of the ovary requires much care. You will get the V best idea of its structure by taking one which has V just burst open , and begun to discharge its seeds (Fig. 41). The outside will then be seen to consist of four pieces (valves), whilst the centre is occupied by a slender four- winged col- umn, (Fig. 42), in the grooves of which the seeds are compactly arr?.nged. The pistil thus consists ^ Fig. 41. fiLElIENTS OP STRUCTURAL BOTANY. 31 3 to the )ve into *wr, and As the is gam- in each is also Each lied the ►rdinary ts), four 3 calyx yle, and 3onsists ) flower tamina- get the ructure ich has I bogun 3s (Fig. ill then af four 1st the by a d col- n the 3 seeds r.nged. insists •I .; of four carpels united together, and is therefore syncarpous. Every seed is furnished with a tuft of silky hairs, which greatly facilitates its transportation by the wind. 42. The Willow-hoi-b furnishes an excellent example of what is called symmetrij. We have seen that the calyx and corolla are each made up of four parts ; the stamens are in two sets of four each ; the stigma is four-lobed, and the ovary has four seed-cells. A flower is symmetrical when each set of floral leaves contains either the same number of parts or a multiple of the same number. Observe that the leaves of our plant are net- veined. The schedule will be filled up as follows : GREAT WILLOW-HERB. Organ Ko. 4 Cohesion. Adhesion. Kemauk?. Calyx. Sei^als. Gamosepa- lous. Superior. Corolla. Petals. 4 Polypetalous. Perigynous. Stamens. Filaments. Anthers. 8 4 Octandrous. Perigynous. F( urs".:ort and four long. Pistil. Carpels. Ovary. Syncarpous. luf'jrior. Seeds provided with tufts of hair 43. Sweet Brier. As in the flower just examined, the ill 32 ELEMENTS OF STRUCTURAL BOTANY. '!;|:): ■ Fig. 43. sepals of Sweet- Brier are not en- tirely distinct; their lower halves cohere to form a tube, and the ca- Ijx is therefore gamosepaloup. The corolla con- sists of five sepa- rate petals of the same size and shape, and is therefore both regular and poly- petalous. The stamens are very numerous, and separate from each other. As in the Pea and the Willow-herb, so in this flower they will be found to be attached to the calyx. They are, therefore, perigynous. 44. To understand the construction of the pistil, ycu must make a vertical section through the roundish green mass which you will find on the under side of the flower. You will then have presented to you some such appearance as that in Fig. 44. The green mass, you will observe, is hollow. Its outer covering is simply the con- tinuation of the calyx-tube. The lining of this calgjc-tube is the receptacle of the f oner ; io it are attached the separate carpels which togethei Fig. 44. ELEMENTS OF STRUCTURAL BOTANY. nn poDstitute the pistil (Fig. 45), just a3 tli carpels of the Buttercup are attached to tlic raised receptacle of that flower. We must remind you again that when- ever the ovary is enclosed in the calyx-tube, and the calyx appears to spring from the *'^' summit of the ovary, the latter is said to be inferior, and the former superior. SWEET-BEIEK. ORGAN. NO. COHESION. ADUESION. REMARKS. Calyx. Sepials. 5 Gamosepalojs Superior. Corolla FetaU. 5 Polypetalous. Perigynous. Stamens. °^ Polyandrous. Perigynous, Pistil. Carpels, (X Apocarpous. Inferior. The hollow re- thecalyx-tubo 40, Crab-Apple. The flower of the Crab-Applo •it- H; If ■'J I '-: ill # 34 ELE:\iENTS OF STRUCTURAL BOTANY. II 1 1 i' ate petals. Tlio stamens are uumerous and are inserted on the calyx. The strncturo of the pistil (Figs. 47, 48), however, is somewhat different. On making a cross section through the young api^le, five cells containing the unripe seeds are seen radiating from the centre. These seed-vessels are imbedded in a fleshy mass, the outer limit of which is marked by a circle of green dots, and outside these dots is the flesh which constitutes the eatable part ol the apple. The inner mass, which encloses the core, belongs to the re- ceptacle, whilst the outer edible por- tion is the enlaiged calyx. At the end opposite the stem will be found the persistent calyx-teeth. We have in this flower, therefore, a si/ncarpous pistil of five carpels, instead of an as in Sweet-Brier. Fig. 48. apocarpous one CRAB- APPLE. ORGAN. NO. COHKSIOX. ADHESION. REMARKS. Calyx. Sepals. 5 GamoseiJalous Superior. Corolla. Petals. 5 Polypctalous. reiigynoiis. 1 Stamens. oc Polyandrous. Perigynous. 1 Pistil. Car]:3ls. ,■) Syncarpous. Inferior. Fniit con?i=(H clii. fly of :■. ; llc.-liy enl.ir , - llll'l.t of t .V Culyx-tubv . } ELEMENTS OF STRI'CTITKAL BOTANY. ar, CHAPTER VI. EXAMINATION OF A PLANT WITH EPIGYNOUS STAMENS WATER PARSNIP. Via- 51. t Fig. 50. Fig. 49. 4G. Water-Parsnip. This is a common swamp plant in Canada ; but if any diffi- \)><^j culty be experienced in procuring C'*^'^ specimens the flower of the com- mon Carrot or Parsnip may be substituted for it, all these plants being closely related, and differ- ing but slightly in the structure of their flowers. Notice first the peculiar ap- pearance of the flower cluster. (Fig. 49.) There are several pedicels, nearly of the same length, radiating from the end of the peduncle, and from the end of each pedicel radiate in like manner a number of smaller ones, each with a flower at its extremity. Such a cluster is known as an wnbel. If, as in the present case, there are groups of secondary pedicels, the umbel is compound. As the flowers are very small we shall be obliged to use the lens all through the examination. Even with its aid you will have a little difficulty in making out the calyx, the tube of which, in this flower, adheres to the surface of the ovary, as in Willow-herb, and is reduced above to a mere rim or border, of five minute teeth. The petals are five in number, and free from each other. Observe that each of them is incurved at its extremity. (Fig. 60.) They are inserted on a disk which crowns the i, 86 fiLftMENtS OP STtlUCTTJtlAL BOTANV. ovary f as are also the five stamens, which are hence said to be epvjynoiis. In the centre of tlio flower are two short styles projecting ahove the disk, and a vortical section throngh the ovary (I'ig. 51) shows it to he two- celled, with a single seed suspended from tlie top of each cell. WATER-PARSNIP. ORGAN. NO. COHESION. ADHESION. IlKMAllKS. Calyx. Sepal's. 5 Gamosepalous. Superior. Ciilyv-toctU rl- Uiot.t obsolete. Corolla. Petals 5 Polypotalous. Epigynous Petals incurved. Stamens. 5 PcutaDtlrous. Epinynous. Pistil. Carpels. 2 Syncarpous. Inferior. 1 CHAPTER Vn. EXAMINATION OF COMMON PLANTS WITH EPIPETALOUS STAMENS - — DANDELION CATNIP- 47. Dandelion. The examination of this flower will be somewhat more difficult than that of any we have yet undertaken. Provide yourselves with specimens in flower and iu seed. The root of the plant, like that of the Mallow, is a tap-root, f- H ELEMENTS OP STRUCTURAL BOTANY. S7 KS. hhrl- 'lote. urv'c d. Fig. 52. The stem is almost suppressed, and, as in the case of the llepatica, the leaves are all radical. They are also net- veined. Tlio flowers are raised on scapes, which are hollow. At first sight the flower appears to have a calyx of many sepals, and a corolla of many petals. Both of these appearances, however, are contrary to facts. With a sharp knife cut the flower through the middle from top to bottom. (Fig. 52.) It will then appear that the flower or rather jhwer-head, is made up of a large number of distinct pieces. With the point of your needle detach one of these pieces. At the lower end of it you have a small body resembling an un- ripe seed. (Fig. 53.) It is, in * 3t, an ovary. Just above this there is a short bit of stalk, sur- mounted by a circle of silky hairs, and above this a yellow tube with one side greatly prolonged. This yellow tube is a corolla, and a close examina- tion of the extremity of its long side will show -pl^ the existence of five minute points, or teeth, from which we infer that the tube is made up of five coiier- cnt petals. As the corolla is on the ovary it is said to be Epujipums. Out of the coi^olla protrudes the long style, divi- ded at its summit into two stigmas. To discern the stamens will require the greatest nicety of observation. Fig. 54 will •ilp you in your task. The stamens are five in number. They are inserted on the tube of the corolla (epipetalous) and their anthers cohere (Fig. 55) and form a ring about the style. When the anthers are united y[r,, 54. in this way, the stamens are said to be syngenesious. \i lliii' i-{ 88 ELEMENTS OF STRUCTURAL ROTANY. 48. It appears, tlien, that the Dantleliou, instead of being a single flower, is in reality a compound of a great many flowers upon a common recep- tacle, and what seemed at first to be a calyx is, in Fig. 55. reality, an involucre, made up of many bracts. But have the single flowers, or florets, as they are properly called, no calyx ? The theory is that they have one, but that it is adherent to the surface of the ovary, and that the tuft of silky hairs which we xed is a prolongation of it. Now turn to your specimen having the seeds ready to blow away. The seeds arc all single ; the little bit of stalk at the top has grown into a long slender thread, and the tuft of hairs has spread out like the rays of an umbrella (Fig. 56). But though the seetls are inva- riably single, it is inferred from the two- lobed stigma that there are tivo carpels. 49. Flowers constructed on the plan of the Dandelion are called composite flowers. A very large number of our common plants have flowers of this kind. The May-weed, which abounds in waste places everywhere, the Thistle, and the Ox-Eye Daisy are examples. DANDELION. Utf Fig. 56. Organ. No. Cohesion. Adhesion. Remarks Calyx. Sepals. 5 Gamoseimlous. Superior. The number of sepals is inferred from analogy to be five. Corolla. retals. 5 Gauiopetalou-'. l-.pigynouB. Stamens. 5 Syngenesious. Epipotaloua. Pistil. Carpels. 2 Syrcarpous, Tnfpi ior. Numberof car- tels inferred from *,..r^;i3«l of stigmas. ELEMENTS OF STHUCTUHAr. HOTANY. 30 50. Catnip. Note carefully the appearance of the item. It is siiHure, lie :illary The caly Fif,'. 57 ^RK8 irubor of ivferred alogy to erof car- ferred cliisten tube (Fig. 57) terminating in five sharp teeth, and you may observe that the tube is a Httle longer on the up- per side (that is, the side towunis the stem) than on the lower. The corolla is some- what peculiar. It has somewhat the ap- pearance of a wide open mouth, and is known as a lut the single style and the two-lobed stigma will warn you against this supposition. The ovary really consists of tiro carpels, each of two deep lobes, and, as the seeds ripen, these lobes form four little nutlets (Fig. 00), each contain- ':/ ing a single seed, Fig. 59, I s "I. 9. I 40 ELEMENTS OF STRUCTURAL BOTANY. til; 61. The group of plants to which Catnip belongs is easily distinguished by the square stem, irregular corolla, and four stamens. Fig. 60. CATNIP. OBGAN. NO. 5 5 4 COHESION. ADHESION . EEMABKS. Calyx. Sepals. Gamosepalous. Inferior. Corolla. Petals. Gamopetalous Hypogynou.s. Epipetalous Two-lipped. Up- per lip of two,' and lower of three lobes Lobes of anthers not parallel. Stamens. Anthers. DidyuamouB. Pistil. Carpels. 2 Syncarpous. Superior. i CHAPTER VIII. EXAMINATION OF PLANTS WITH MONOECIOUS AND DIOECIOUS FLOWERS CUCUMBER, WILLOW. 52. Cucumber. You can hardly have failed to notice that only a small proportion of the blossoms on a Cucumber vine produce cucumbers. A great many wither away and are apparently of no use. An atten- tive inspection will show that some of the blossoms li i: ELEMENTS OF STRUCTURAL BOTANY. 41 have oblong fleshy protuber- ances beneath them, whilst others are destitute of these attachments. Select a flower of each kind, and examine first the one with the protuberance (Fig. 61), which latter, from its appearance, you will prob- ably have rightly guessed to be the ovary. The situation of the ovary here, indeed, is the same as in the Willow-herb. The Fig. ei. calyx-tube adheres to its surface, and is prolonged to some little distance above it, expanding finally into five teeth. The corolla is gamopetalous, and is adherent to the calyx. Remove now the calyx and the adherent corolla, and there is left in the centre of the flower a short column, terminating in three stigmas, each two- lobed. There are no stamens, 53. Now examine the other blossom (Fig. 62). Calyx and corolla have almost exactly the same appearance as before. Remove them, and you have left three stamens grow- ing on the calyx-tube, and slightly united by their anthers Fig. 62. (syngenesious). There is no pistil. You see now why some blossoms produce cucumbers, and others do not. Alost of the blosf.oms have no pistil, and are termed staminate or sterile flowers, whilst the others are pistillate or fertile. Flowers in which ■ Si 42 ELEMENTS OF STRUCTURAL BOTANY. either stamens or pistils are wanting are also tailed im- 'perfect. When staminate and pistillate flowers grow on the same plant, as they do in the case of the Cucumber, they are said to be momccious. 54. In plants of this kind the pollen of one kind of blossom is conveyed to the stigmas of the other kind, chiefly by insects, which visit the flowers indiscrimin- ately, ill search of honey. The pollen dust clinga to tlieir hairy legs and bodies, and is presently rubbed o£f upon the stigma of some fertile flower. 55. In order to describe monoecio-. flowers, our schedule will require a slight modification. As given below, the symbol f stands for " staminate flower," and the symbol | for " pistillate flower." CUCUMBER. !' ORGAN. NO. COHESION ADHESION. BEMABKS. Calyx. Sejjals. 5 Gamosepalous Superior. • Corolla. Petals. r, Gamopetalous Perigynous. + Stamens. 3 SyngenesiouB. Perigynous Two anthers are 2— celled, and one 1— celled. t Pistil. Carpels. o I Stamens. o t Pistil. Carpels. 8 Syucarpons. Inferior. KLeMents op structural botany. 48 Fig. 63. 5G. "Willow. The flowers of most kinds of Willow appear in spring or early summer, before the leaves. They grow from the axils in long close clusters called catkins or aments. Collect a few of these froyn the same tree or shrub. You will find them to be exactly alike. If the first one you examine is covered with yellow stamens (Fig. G3), all the rest will likewise consist of sta- mens, and you w411 search in vain for any appearance of a pistil. If, on the other hand, one of your catkins is evidently destitute of stamens, and consists of oblong ins- tils (Fig. 64), then all the others will in like manner be found to be without stamens. Unlike our Cu- cumber plant, the stami ]iate aud pistillate flowers of the Willow are borne on dijerent plants. • These flowers are therefore said to be diiiwioKs. As a general thing, staminate and pistil- late catkins will be found upon trees not far apart. Procure one of each kind, and examine first the stami- nate one. You will probably find the stamens in pairs. Follow any pair of filaments down to their insertion, and observe that they spring from the axil of a minute bract (Fig. G5). These bracts are the scales of the catkin. There is no appearance of either calyx or corolla, and the flowers are therefore said to be achlamy- deouSf that is, without a covering. Now look Fig. 65 at the fertile catkin. Each pistil will, like Fig. 64. 1 '! 44 ELEMENTS OF STRUCTtJKAL BOTANY. fei mr ii' .■ Hi' ji:i ';i! the stamens, be found to spring from the axil of a scale (Fig. 66). The stigma is two-lobed, and on carefully opening the ovary you observe that though there is but one cell, yet there are two rows of seeds. We therefore infer that the pistil consists of two carpels. The pistillate flowers, like the staminate, are achlamydeous. In dioecious plants, the process of fertilization p. gg is assisted by insects, and also very largely by the wind. HEART-LEAVED WILLOW. ORGAN NO. COHFBION. ADHESION. BEMARKS. Calyx. Corolla. t Stamens. + Pistil. -' Diandrous. \ Stamens. •• t Pistil. Carpels. 2 Syncarpous. t 1 r ; I : ELEMENTS OF STRUCTURAL BOTANY. 46 CHAPTEK IX. CHARACTERISTICS POSSESSED IN COMMON BY ALL THE PLANTS PREVIOUSLY EXAMINED. STRUCTURE OF THE SEED IN DICOTYLEDONS. 67. Before proceeding further in our examination of plants, we shall direct your attention to some characters of those already examined, which they all possess in common. The leaves of every one of them are net- veined. Some leaves, at least, of each of them have dis- tinct petioles and blades. The parts of the flowers we found, as a general thing, to be in Jives. In one or two instances they were in /ours, that is, four sepals, four petals, and so on. 68. Now, in addition to these resemblances there are others which do not so immediately strike the eye, but which, nevertheless, are just as constant. One of these is to be found in the structure of the embryo. Take a cucumber or pumpkin seed, and having soaked it for some time in water, remove the outer coat. The body of the seed will then readily split in two, except where the parts are joined at one end. (Figs. 67, 68, 69). The thick Fig. 67. Fig. 68. Fig. 69. lobcs are Called cotyledons, or seed- leaves, and as there are two, the embryo is dicotyledonous. The pointed end, where the cotyledons are attached, and from which the root is developed, is called the radicle. Between the cotyledons, at the summit of the radicle, you will find a minute upward projection. Tliis is a bud, which is known as the plumule. It developes into the stem. 69. If you treat a pea or a bean (Figs. 70, 71), in the same manner as the cucumber seed, you will find it to b« m rmp' 4G ELEJiENTS OF ST.:UCTL1:a^ iiUTx^NY. Ml ir ^' lifff^!'' '^' ' ■ constructed ou the same plan. The em- bryo of the bean is dicotyledonous also. But you will observe that in these cases the embryo occupies the whole of the inte- rior of the seed. In describing the seed of the Buttercup, it was pointed out that the embryo occupies but a very small Fig. 71. space in the seed, the bulk of the lat- ter consisting of albumen. Seeds like those of the But- tercup are therefore called albuminous seeds, while those of the Bean and Pea are exalbuminous. But, notwithstand- ing this difference in the structure of the seed, the emfJryo of the Buttercup, when examined under a strong magnifier, is found to be dicotyledonous like the otiiers. In sho: t, the dicotyledonous embryo is a character common to all the plants we have examined — common, as a rule, to all plants possessing the other characters enumerated above. From the general constancy of all these char- acters, plants possessing them are grouped together in* a vast Class, called Dicotyledonous plants, or, shortly, Dicotyledons. 60. Besides the characters just men!,ioned, there is still another one of great importance, which Dicotyle- dons possesses in common. It is the manner of growth of the stem. In the Willow, and all our trees and shrubs without exception, there is an outer layer of bark on the stem, and the stem increases in thickness, year by year, by forming a new layer just inside the bark and outside the old wood. These stems are therefore called exogenous^ that is, outside groicers. Now, in all dicotyledonous plants, whether herbs, shrubs or trees, the stem thickens in this manner, so that Dicotyledons are also Exogens. ELEMENTS OF STRUCTURAL BOTANY. 47 CHAPTER X. EXAMINATION OF COMMON PLANTS CONTINUED. DOo's-TOOTH VIOLET, TRILLIUM, INDIAN TURNIP, CALLA, ORCHIS, TIMOTHY. 01. Dog's-tooth Vi let. This plant (Fig. 72)which flowers ill Spring, may be pretty easily recognised by Fig. 72. ^;l. , l\ I its peculiar blotched leaves. It may be found in rich ) 'I r^i 48 ELEMENTS OP STRUCTURAL BOTANY. - I! it m lU- moist pasture lands and low copses. The name "Violet" is somewhat unfortunate, because the plant is not in any way related to the true Violets. To obtain a com- plete specimen requires some trouble, owing to the fact that the root is commonly six inches or so below the surface of the ground'; you must therefore insert a spade or strong trowel sufficiently deep to avoid cutting or breaking the tender stem. Having cleared away the adhering earth, you will find that the roots proceed from what appears to be the swollen end ot the stem. This swollen mass is coated on the outside with thin scales. A section across the middle shows it to bd more or less solid, with the stem growing up through it from its base. It is, in fact, not easy to say how much of this stem-like growth is, in reahty, stem, because it merges gradually into the scape, which bears the flower, and the petioles of the leaves, which sheathe the scape. The swollen mass is called a bulb, 62. The leaves are two in number, gradually narrow- ing at the base into sheaths. If you hold one of them up to the light, you will observe that the veins do not, as in the leaves of the Dicotyledonous plants, form a network, but run only in one direction, namely, from end to end of the leaves. Such leaves are consequently called straight-veined. 63. In the flower there is no appearance of a green calyx. There are six yellow leaves, nearly alike, ar- ranged in two sets, an outer and an inner, of three each. In such cases, we shall speak of the colored leaves collectively as the perianth. If the leaves are free frcm each other, we shall speak of the perianth as pohj- 7 7 v//oi/s, but if they cohere we shall describe it as ffamo- fiLEMENTS OF STRo, URAL BOTANY. id phyllous. Stripping off the loaves of the perianth we find six stamens, with long upright anthers which open along their outer edges. If the anthers he pulled off, the filaments will he found to terminate in long shaip points. The pistil (Fig. 73) has its three parts, ovary, style, and stigma, well marked. The stigma is evidently formed hy the union of three into one. The ovary, when cut across, ] if,'. 74. is seen to be three-celled (Fig. 74), and is therefore syncarpous. Fig. 73. ii! DOG'S-TOOTH VIOLET. I! ORGAN. NO. G G COHESION. ADHESION. RKMARK8. roriantli. Leaves, Polyphyllous. Inferior. Stamens. Hexandrous. HypogynouB. rilaments ter- minating in Bliarj) j)oint8. Pistil. Carx)els. 3 Syncarpous. Superior. 04. Trillium. This plant (Fig. 75) may he found in flower about the same time as the one just described. The perianth of Trillium consists of six pieces in two sets, but in this case the three outer leaves are green, like a common calyx. The stamens are six in num- ber. There are three styles, curving outward?, tho whole of the iuner side of each being stigmatio. I !,> ii i.6 ■ 5" 50 ELEMENTS OF STRUCTUHAL BOTANY. fli ?n >ri I. The ovary (Fig. 76) is six- aiiglecl, and on being cut across is seen to be three- celled. 05. Comparing this flower with that of Dog's-tooth Vio- let, we find the two to exhi- bit a striking resemblance in structure. But in one respect the plants are strikingly un- like : the leaves of the Trillium are net-veined (Fig. 77), as in the Exogens. From this cir- cumstance we learn that we cannot altogether rely on the veining of the leaves as a con- stant characteristic of plants whose parts are not in fives. Fig. 75. TEILLIUM. m i\m I I! ORGAN. NO. COHESION. ADHESION. REMABES. Perianth. Sepals. Petals. 3 3 6 Polyphyllous. Inferior Sepals persist- ent. Stamens. Hexandrous. Hypogynoua. Pist'l. Carpels. 3 Syncarpous. Superior. The inner face of eac'i style stigmatic. Leavea net-veined. ELEMENTS OF STUUc'lURAL BOT.^NV. 51 66. I ndian Turnip. This plant may be easily met with in our woods in early summer. If you are not famihar with its appearance, the annexed cut (Fig. 78) Fig. 78. will help you to recognise it. Procure several speci- mens ; these will probably at fiibt seem to you to be alike in every respect, but out of a number, some are pretty sure to differ from the rest. Notice the bvalb from which the stem springs. It differs from that of the Dog's-tooth Violet, and Lilies generally, in being a solid mass. It is called a conn. Bjtwcen the pair of !'H \\\ m m li : 1 oiti 62 ELEMENTS OF S'lLlt 1 1 i.A.. IJOTANY. lit r ill Hi 1 Fig. 79. leaves you ooserve a curious strip- ed sheath, having an arching, hood-like top, and enclosing an up- right stalk, the top of which almost touches the hood (Fig. 79). Can this he a flower ? It is certainly the only thing ahout the plant II i 'Ml which at all resembles a flower, ((I Ij! iJJf and yet how different it is from any we have hitherto examined ! Care- fully cut away the sheaths from all your specimens. Most, and per- haps all, of them will then present an appearance like that in Fig. 80. If none of them be like Fig. 81, it will be well to gather a few more plants. We shall sup- pose, however, that you have oeen fortunate in obtain- ing both kinds, and will proceed with our examination. Take first a specimen cor- responding with Fig. 80. Around the base of the column are compactly arrang- ed many spherical green bodies, each tipped with a little point. Separate one of these from the rest, and cut it across. It will be found to contain several ovules, and is, in fact, an ovary, the point at the top being a stigma. In the autumn, a great change will have taken place in the appearance of plants like the one we are now examining. The arched hood will have disappear- ed, as also the long naked top of the column, whilst the part below, upon which we are now engaged, will havQ Fit ^^^O. ■'\g.81 ELEMENTS OP STRUCTURAL BOTANY. 58 vastly increased in size, and become a compact ball of red berries. There can be no doubt, then, that we have here a structure analDgous to that found in tlio Cucum- ber and the Willow, the fertile, or pistillate, flowers being clustered together sei)arately. lUit in the Cucum- ber all the flowers were observed to be furniHhed with , calyx and corolla, and in the Willow catkins, though floral envelopes were al)sent, each pair of stamens and .each pistil was subtended by a bract. In the present plant there are no floral envelopes, nor does each pistil arise from a separate bract. G7. But, you will now ask, what is this sheathing hood which we find wrapped about our column of pistils ? There is no doubt that we must look upon it as a hract^ because from its base the flower-cluster springs. So that, whilst the flowers of Indian-Turnip are, like those of Willow, imperfect and dioecious, the clusters dilfer in having but a single bract instead of a bract under each flower. G8. We must now examine one of the other speci- mens ; and we shall have no difficulty in determining the nature of the bodies which, in this case, cover the base of the column. They are evidently stamens, and your magnifying-glass will show you that they consist mostly of anthers, the filaments being extremely short, and that some of the anthers are two-celled, and some four-celled, all discharging their pollen through little holes at the top of the cells. GO. The column upon which, in plants like Indian- Turnip, the flowers are crowded, is known as a spadLvy ] and the surrounding bract as a spathe. You will observe that the leaves of this plant are net- veined^ as we found them in the Trillium, !? 54 ELEMENTS OF STIIUCIURAL BOTANY. INDIAN-TURNIP. W'^' I' -T m ff OBaAN. NO. COHE8IOX. ADHESION. \ stamens. 1 Monandrous. :P.3til. Carpels. 1 Apocarpous. Flowers crowded o ■ a spadix, and surrounded by a spatho. Leaves net-veined. 70. Marsh Calla. This plant must be looked for in low marshy grounds, where it will be found in flower generally in the month of June. With the knowledge which you have of the structure of Indian-Turnip, you will hai'dly doubt that the Calla is closely related to it. You will easily recognize the spadix and the spathe (Fig. 82), though in the present instance the snadix FiR. RJ Fig. 83. ELEMENTS OF STRUCTURAL BOTANY. 55 bears flowers to the ^op, ana mq spathe is open instead of enclosing the cohimn. Observe, however, tiiat the veining of the leaf (Fig. 83) is different, that of Calla being straight, Hke the Dog's-tooth Violet. There is also a difference in the flowers. Tliose of Indian-Tur- nip were found to be dioecious, but the spadix, in the present case, bears both stamens and pistils, and the lower flowers, if not all, are perfect ; some- times the upper ones consist of stamens only. Fig. 84 shows one of the perfect flowers much eulirged. The stamens, it will be observed, have two-celled anthers, opening lengthwise. MARSH CALLA. Fig, 84.- onoAN. NO. COHESION. ADHESION. Poriantli. Wanting. Sttimena G Hoxaudrous. IlyiiogynouR. Pistil. Carj^cls. 1 Ai'ocavpous. Supei-ior. 71. Showy Orchis. T!io llower of this plant (Figs. Hi"), 80) is provided with floral envelopes, all col- oured like a corolla. As in Dog's-tooth Violet, we shall call them collectively the perianth, although they are not all alike. One of them projects forward in front of the flower, forming the Up, and bears under- neath it a long hollow simr, which, like the spurs of Columbine, is honey-bearing. The remaining five con- verge together forming a kind of arch over the centre of the flower. Each flower springs from the axil of a Is ii,|i wmmmummm ' 1 V.'.FMEST^ OF STniTTURAT, noTAKV I 1 i a ■>\^ r/ i.i Fi«. 80. leaf-like bract, Jiiid is iipiuueiitly raised ou a pedicel. What seems to be a jiedicel, however, will, if cut across, prove to be the ovary, which iu this case is inferior. Its situation is similar to the situ- ation of the ovary in Willow-herb, and, as in that liower, so in this the calyx-tube ad- heres to the whole surface of the ovary, and the tlirce outer divisions of the perianth are simply upward extensions of this tube. No- tice the peculiar tuist in the ovary. Tlie Fig 86 effect of this twist is to turn the lip awjiy ELEMENTS OF STRUCTUKAL BOTANY. 67 fi the scape, aiK lower petal iust give it the appearance of being il of the }()>pei' one, as it really is. 72. The structure of the stamens and pistils remains to be examined, and a glance at the flower shows you that we have here something totally different from the common arrangement of these organs. In the axis of the flower, immediately behind the opening into tlie spur, there is an upward projection known as the cohiimi^ The face of this column is the stigma ; on each side of the stigma, and adhering to it, is an anther-cell. Those cells, though sejiarated by the column, constitute hut a siuffle stamen. The stamen, then, in this case is nnitrd with the pistil, a condition which is described as (/i/nan- (IroKs. 73. If you have a flower in which the anther-cv lis are bursting open, you will see that the pollen does not issue from them in its usual dust-like form, but if you use the point of your needle carefully you may remove the contents of each cell i)i a rums. These pollen masses are of the form shown in Fig. 87. The grains are kept together by a fine tissue or web, and the slender stalk, upon which each pollen mass is raised, is attached by its lower end to a sticky disk on the front of the stigma just „. „„ above the mouth of the spur. Insects, in their Fi{4. 87. ^ eftbrts to reach the honey, bring their heads in contact with these disks, and when they fly away carry tlio pollen-masses with them, and deposit them on the stigma of the next flower visited. In fact, without the aid of insects it is difticult to see how flowers of this sort could be fertilized at all. If: p 5d ELEMENTS OF STRUCTURAL BOTANY. SHOWY ORCHIS. I 1 $ ORGAN. NO. COHESION. ADHKSION, KEMARK8. Poriaiith. Leaves. 6 Gamoiihjllou' , Superior. fitameiiB. 1 Monandrous. 1 Polkn-BniiiiS Gynandrous. j collected in 1 inns es. Pistil. Carpels. 8 Syncarpous. Inferior. Ovary twisted. 74. Timothy. The top of a stalk of this well-known grass is cylindrical in shape, and upon examination will be found to consist of a vast number of similar pieces compactly arranged on very short pedicels about the stalk as an axis. Carefully separate one ( f these pieces from the rest, and if the grass has not yet come into flower the piece will present the appearance shown in Fig. 88. In Fig. 88. this Fig. the three points in the middle are the protruding ends of stamens. The piece which you have separated is, in fact, a flower enclosed in a pair of bracts, and all the other pieces which go to make up the top are flowers also, and, except perhaps a few at the very summit of the spike, precisely similar to this one in their structure. 75. Fig. 89 is designed to help you in dissecting a flower which has attained a greater degree of developement than tlio one shown in Fig. 88. Her& the twv) bracts which enclose tlie flower have been drawn asundor. Ti the-ie bracts l.^^, ^, the name ghnnes is appiied. T'ey are present i.i all ELEMENTS OF STRUCTLRAL BOTANV. 59 plants of the Grass Family, and are often louud enclos- ing several flowers instead of one as in Timothy. Inside the glumes will be found a second pair of minute chaff-like bracts, which are known as ])alets or pales. These enclose the flower proper. 76. The stamens are three in number, with the anthers fixed by the middle to the long slender filameut. The anthers are therefore versatile. The styles are two in number, bearing long feathery stigmas. The ovary contains a single ovule, and when ripe forms a seed- like grain, technically known as a caryopsis. TIMOTHY. ORGAN. NO. COHESION. ADHESION. Olumes. 2 Palets. 2 Stamer.s. 3 Triandrous. Hypogynous. PiBtil. Carpel". 1 Apocarpous. \ Superior. f t CHAPTER XI. COMMON CHARACTERISTICS OF THE PLANTS JUST EXAMINED. STRUCTURE OF THE SEED IN MONOCOTYLEDONS. 77. It is now to be pointed out that the six plants last examined, viz., Dog's-tooth Violet, Trillium, Indian Turnip, Calla, Orchis, and Timothy, thougl) differing in various particulars, ytt have some chaif*' TmSKM GO ELEMENTS OF STRUCTURAIi BOTANY. it ters common to all of them, just as the group ending with Willow was found to be marked by characters possessed by all its members. The flowers of Dicoty- ledons were found to have their parts, as a rule, in fours or fives ; those of our second group have them in threes or sLres, never in fives. 78. Again, the leaves of these plants are straight- veined, except in Trillium and Indian-Turnip, which must be regarded as exceptional, and they do not as a rule exhibit the division into petiole and blade which was found to characterize the Exogens. 79. We shall now compare the structure of a grain of Indian Corn with that of the Cucumber or Pumpkin seed which we have already examined (page 45). It will facilitate our task if we select a grain from an ear which has been boiled. And first of all, let us observe that the grain consists of something more than the seed. The grain is very much like the achene of the Buttercup, but differs in this respect, that the outer covering of the former is completely united with the seed-coat underneath it, whilst in the latter the true seed easily separates from its covering. Romove the coats of the grain, and what is left is a whitish starchy- looking substance, having a yellowish body inserted in a hollow (Fig. 90) in the middle of one side. This latter body is the emhrtjo, and may be easily removed. All the rest is aihmnen. Fig. 91 is a front view of the embryo, and Fig. 92 shows a vertical section of the same. Tlie greater part of the embryo consists of a single cotyle- don. The radicle is seen near the base, Fir. 90 rig. 91 Fi-. w. and the plumule above. 80. Comparing the result of our obt^ei vations with fiLfiMENTS OF STRUCTURAL BOTANY. 61 tvhat we have already learned about the Cucumber seed, we find that whilst in the latter there are iwo cotyledons, in the present case there is but mcj and this peculiarity is common to all th« plants just exam- ined, and to a vast number of others besides, which are consequently designated Monocotyledonous plants, or shortly Monocotyledons, The seeds of this great Class may differ as to the presence or absence of albu- men, just as the seeds of Dicotyledons do, but in the number of their cotyledons 'they are all alike. The Orchids, however, are very peculiar from having no cotyledons at all. 81. In addition to the points just mentioned, viz : the number of floral leaves, the veining of the foliage leaves, the usual absence of distinct i^etioles, and the single cotyledon, which characterize our second great Class, there is still another, as constant as any of these, and that is, the mode of growtli of the stem, wiiicli is quite at variance with that exhibited in Dicotyledonous plants. In the present group the increase m the thickness of the stem is accomplished not by the deposition of circle after circle of new wood outside the old, but by the production of new wood-fibres through the interior of the stem generally, and the consequent swelling of the stem as a whole. These stoms are therefore said to be endogenous, and the plants com- posing the group are called Endogens, as well as Monocotyledons. We shall explain more fully the structure of exogen- ous and endogenous stems, wl en we come to speak of the minute structure of phmts in a subsequent chapter. I 02 ELEMENTS OE STELCiflwU-. UOTANY CHAPTER XII. MORPHOLOGY OF ROOTS, STEMS, AND FOLIAGE-LEAVES. 82. From what has gone before, you should now be tolerably familiar with the names of the different organs of plants, and you have also had your attention directed to some modifications of those organs as they occur in different plants. In all these cases, the adjective terms, which botanists use to distinguish the variations in the form of the organs, have been placed before you, and if you have committed these carefully to memory, you will have laid a good foundation for the lessons which follow on Morphology, the name given to the study of the various forms assumed by the same organ in different plants, or in different parts of the same plant. In some instances, the terms employed, being derived from Latin and Greek, and specially devised for botanical purposes, may seem difficult to learn. We believe, however, that this difficulty will be found to be more apparent than real. You will be surprised at the ease with which the terms will occur to your mind if you learn them with the help of plants which are every- where within your reach — if you be not satisfied with being mere book-botanists With a good Inany terms you will find no difficulty whatever, since they will be found to have the same meaning in their botanical applications as they have in their everyday use. ELEMENTS OF STRUCTUPAL B^'TANY. 63 83. The Root. This organ is called the desceiiclmg axis of the plant, from its tendency to grow downward into the soil from the very commencement of its devel- opement. Its chief use is to imbibe liquid nourishment, and transmit it to the stem. You will remember that in our examination of some common seeds, such as those of the Pumpkin and Bean (Figs. C7-71), we found at the junction of the cotyledons a small pointed pro- jection called the radicle. Now, when such a seed is put into the ground, under favourable circumstances ol warmth and moistm-e, it begins to grow, or germinate, and the radicle, which in reality is a minute stem, not only lengthens, in most cases, so as to push the cotyle- dons upwards, but developes a root from its lower ex- tremity. All seeds, in short, when they germinate, ))roduce roots from the extremity of the radicle, an^ roots so produced are called primary roots. 84. There are two well-marked ways in which a pn mary root may develope itself. It may, by the down ward elongation of the radicle, assume the form of y distinct central axis, from the sides of which branches or fibres are given off, or root-fibres may spring in a cluster from the end of the radicle at the very 1>^'^ commencement of growth. If the root grow in the first way, it will be a tap-root (Fig. 93), examples of which are furnished by the Car- rot, the Mallow, and the Bean ; if in the sec- ond way, it will be a Jihrous root, examples of which are furnished by the Buttercup (Fig. 1) and by the entire class of Monocotyledcnous or Endogenous plants. 86. Tap-roots receive different names, ac- pig. 93, II:, 64 ELEMENTS Oip STRUCTURAL BOTANY. Fig. [hi. cording to the i)articular shape they hap- pen to assume. Thus, the Carrot (Fig. 94) is coiiica}, because from a broad top it tapers giadunlly and regularly to a point. The lladi^h, being somewhat thicker at the middle ilian at either end, is spindle-shaped. The Turnip, and roots of similar shape, are luijn. form (nojms, a turnip). Tlicse fleshy tap-roots belong, as a rule, to bi- ennial plants, and are designed as storehouses of food for the plant's use during its second ye^Cr'sgrowth. Occasion- ally ^brous roots also thicken in the same manner, as in the Peony, and then they are said to he fascicled or clustered. (Fig 95.) 86. But you must have observed that plants some- times put forth roots in addition to those develop- ed from the end of the radicle. The Verbena of Pi, ,)- of our gardens, for ex- Fig. 96. ELEMENTS OF STRUCTl TAL B .'lANV. o; ample, will tako root at evory joiut, if the stem be laid upon tlie ground (Fig. [){')). Tlie runners of the Strawberry take root at their extremities : and nothiug is more fauiiliar than tlwit cuttings from various plants will make roots for themselves if put into proper soil, and supplied with warmth and moisturr. All such roots are produced from some other part of the stem than the ridicle, and are called secomhirij or adventitious roots. AVhen such roots are developed from parts of the stem wliich are not in contact with tip ground, they are (irrial. 87. There are a few curious plants whose roots nevi r reach the ground at all, and which depend altogether upon the air for food. These are called ej>ij>Inilts There are others whose roots penetrate the stems ami roots of other plants, and thus receive their nourisi • ment as it were at second-hand. These are juiruaiui- plants. The Dodder, Indian-Pipe, and Beech-drops, of Canadian woods, are well-known examples. 88. i he Stem. As the root is developed from the lower end of the radicle of the embryo, so the stem is developed from the upper end, but with this important dillerence, that a hud always precedes the formation of the stem, or any part of it or its branches. Between the cotyledons of the Beau (Fig. 71), at the top of the ladide, we found a mintite bud called the plumule. Out of this bud the first bit of stem is developed, and during the subsequent growth of the plant, wherever a branch is to be formed, or a main stem to be jjrolonged, there a bud will invariably be found. The branch buds are alwavs in the axils of leaves, and so are called axiHanj. Adventitious buds, however, are sometimes produced in plants like the Willow, particularly if the 66 ELiiMENTS OF STRUCTURAL BOTANY. 1^ ■m rt' ffcm has been wounded. The bud from wliich the main stem is developed, or a branch continued, is of course at the end of the stem or branch, and so is 'cn7ii7i((l. 81). If you examine a few stems of plants at random, you will probably find some of tlicm quite soft and easily compressible, while others will be firm, and will resist compression. The stem of a Beech or a Currant IS an instance of the latter kind, and any weed will serve to illustrate the former. The Beech and the Currant have uooih/ stems, while the weeds are herde ceoits. Between the ]^eech and the Currant the chief difference is in size. Tlie Beech is a ttee^ the Currant a shrub. But you are not to suppose that there is a liara and fast lino between shrubs and trees, or between herbs and shrubs. A series of plants could be constructed, commencing with an unquestionable herb, and end- ing with an unquestionable tree, but embracing plants exhibiting such a gradual transition from herbs to shiubs, and from shrubs to trees, that you could not say at what precise point in the series the changes occurred. 90. The forms assumed by stems above ground are numerous, and they are described mostly by terms in common use. For instance, if a stem is weak, and trails along the ground, it is trailing, or prostrate , and if, as in the run- ners of the Straw- berry, it takes root on the lowe v side, then it is crecpiny. Many weak stems raise Fig. 97. tl t( i1 -* "•; ELEMENTS OF STRUCTURAL BoTANY. 61 themselves by clingiug to any suppoH tliat may happen to bo within their reach. In some instances the stem itself winds round the support, assuming n spiral form, as in the Morniug-Glory, the Hop, and the Bean, and is therefore distinguished as tinnimj. In other cases the stem puts forth thrt'ad-like leafless branches calh^d tcndrHs (Fig. 97), which grasp the support, as in the Virginia Creeper, tlie Grape, and the Pya (Fig. 98), or sometimes the leaf-stalks serve the same purpose, as in the Clematis or Virgin's Bower. In these cases the stems are said to dimh. The stems of wheat and grasses generally are known as ciibna. They are jointed, and usually hollow except at the joints. rig oh. 91. Besides the stems which grow above ground, there Fig. 99. 1; a Ihj are varieties to be found below the surface. Pull up q, t:!,i;MENTS OF STRrCTURAl. BOTAVY. P- !•*'. m n s Potato ].lujit, ajul cKiML^iuo tiio iDKl'Tijnuiiid portion rFig DIM. It is not iiu'rol.abic tiiat von wilju'i'ara tlio wlioie as a mass of roots, 'tnit a vn-y littln trouble wilJ niuloccive you. Many of tijo llbrcs are uunucs tionably voota, l)ut an inspection of those liavnig pota- toes at t.MC enJf] of thorn will rIiow you tliat tlioy are nu;tc (lilliTont from those whicli liave not. The former wiL bo found to be furuishcl with little scales, answer- ing to leaves, each with a minute bu.l in the axil : and t]:c 1)1 tatocH tlieni- K( Ivf s exhibit buils of the FjiUio lvi)Kl. The potato, in short. iB only the stroilrn ''in/ c/' <' n iDiiIcnnoHud :uf)n Such HwoJlcn ex- , tremities are known as ndtcrs whilst aie Fit,'. I'O. underground sfem is called a rootstnm, or ''hnooir, and may always be distinguished fioin a true root by t.!ie presence ot buds. The Solomon's Sejd and Toothworf of Canadian woods, and the Canada Thistle, are com mon instances of i)lants jiroduciug these stems. Fig. 100 shows a rliizome. 92. Take now an Onion, and compare it witli a Potato. You will not find any such outside appear- ances upon the former as are prei^cnted by the lalier. The Onion is smodtii, and has no budtf upon its surface. From the under side there spring roots, and thii cir- cumstance will probably suggest that the Onion mur.t be a stem of some sort. Cut the Onion through f om top to lotton (Fig. V:\). It wil' 'hen bo rcen i > bo U^ Jll.EMKNTS OF SIKUCIURAL BOTANY. 69 made up of a lumibcr of coats. Strip off oiic or two, and observe that whilst they are somewhat flesliy where the onion is broadest tliey gradually bcenme thinner to- wards the top. Tiie long green lubes, which project I'ioni the top . ( the Onion during its i^'rowtli, are, in fact, the prolongs) t ions of these coats, liut the tubes are the leaves of the plant. The inn; of our Onion, therefore, con- sists of the jhshif hdsfs (./ (Iw Ixtrrs. Jhit you will observe that at the bottom there is a rather ilat solid part upon which these coats or leaves are inserted, and which nnist consequent- ly bo a steui. Such a stem a-i t!us. with j its deshy leaves, is called a ha''^ If the leaves foini coiits, as in the Onion, the ])ulb is codtvil or iHniciili-il ; if they do not, as in the lines (Fig. 102), it is sodff. 08. Tubers and bulbs, tiien, consist chiefly of masses of nourishing matter ; but there is this difference, that, in the latter, the nourishment is contained in the lleshy Icave.i tJie nselves, whilst, in the former, it forms a mass m'MC t>r less distinct from the buds. Ot, The thickened mass at the bast^ of the stem of our Indian Turrn]> (I'ig. 7H) is more like a tiiber than a bulb in its construction. It is called a conn, or solid bulb. The Crocus nnd Gladiolus of the gardens are other examples. {)"). In the axils of the lea\>'S of the Tiger Lily are piodnced smidl, black, rouTided bodies, which, on exami.. nation, i)rovo lo bo of bulbous structure. They are, in -!;• 1' ^mmm 70 ELEMENTS OF STRUCTIUAL lioTANY. li j\ fact, ImlldetSy and new plants may be grown from tJiem. iiO. Our Hawthorn i> rendcretl formidable by the presonco of stout Siiines (Fig. 103) along the stem and branches. Thcso spinas invariably proceed from the u\ik of leaves, and are, in fact, branches, whose growth has been arrested. Tliey are appendages of the wood, and \ will remain attached to the stem, vj^,. i„:t. even after the bark is stri])pcd oil". They mii.-^t not be conf.iunded with the pnchics (Fig. 101) of the Hose and lirier, which belong strictly to ^By the bark, and come off with it. )lu ()7 Foliage-Leaves. Tiiene orgaua aro usually more or less Hat, and of a green colour. In Mime plants, however, they are extremely thick and succulent ; and in the case of ]>ara- sites, such as Indian-Pipe and lieech-drop;;, jg. 10-1. ^j^^y ^^^^ usually (Mther white or brown, or of some colour other than green. The scaly leaves of underground stems are also, of course, destitute of colour. U8. As i\ general thing, leaves arc extended horizon- tally from the stem or brancli, and turn one side towards the sky and the other towards the ground. But some leaves are vertmd, and in the case of the common Iris each leaf is doubled lengthwise at the base, and sits (Uriilc the next one within. Such leaves are accordingly called CijuitanL 99. As to their arrangement on the stem, leaves are alternate when only one arises from each node l^'ig. 3). li" two are formed at encli node, they are sui-e to bo LLEME.NTS OF STRUCTLUAL BOiA.\ i 71 oil oj.poaite sides of tlio stem, aud so are dosalbed as opjny U(\ Sometimes ther^ . je sovcrpJ leaves at the same uode, ii. w'iitli c^.se they are uhorln or ce-ticillu. (i'ig. ior>). 100. Forrriv^of Foliage-Ler.ves, lAaves preneut an almost endloss va- riety ill tlieir forms, and Hccuracy in describing any given leaf depends ?j i^'ood deal upon the ingenuity of the student in .selecting r.nd combining terms. The chief terms in use will bs /jivon bore. Compare a leaf of t!u' Uoinid-leaved Mallo.7 v;ith ono ?f lied Clover (Figs. 10(1, 107). Each cf them iz fur- FifT. 105. Fig. lOG. Fig. 107. nisbod v.ith a long petiole and a pair of i!Ipr!.s. la the bladjs, however, there is a difYeronco. Ibe bladoot the lorr lor consists of a sinijle piece ; \\i:A, ol llio tatter '■ ill three jcparaic pieces, each of which is en lied p, leaflet,- !/al all Oi which, tjikeu ^^^'ectively, coustiti.tc the Lladc » J iL 11 * I mm /2 elkmf':nts of strt^ tural botany. I*' ■ I af the haf. Tiio leaf of the Mull nv is simple ; that . f the Olover is compound. Butween the siiiiplo ami the compouucl form tluTc ts every possible shade of vM —adation. In the ]\[allow __3 ''^^ ( \'// ^ \/^(^ xeafthe hhes, are not very ^"^~__^\, f \ J '^-' — -~ clearly cloKiied. In tlio ) , ._--,^^"^ Maple (Fig. lOH) they are ^"^ ^ '' well-marked. In otlier cases, again, the lobes arc so nearly separate, that the leaves appear at lirst sight to be really comp"n..d. 101. You will remember that in our exMiiiinr.tions of dicotyledonous plants, we found the leaves ti> 1> * in- variably net-veined. But, though they have ihis geiu r- ul character in common, they diiTer considerably in the details of their veiuing, or venation, as it is called. The two leaves employed as illustrations in the last section will serve to illustrate our meaning here. In the ^lallow, there are several ribs of about ilie sani'^ size, radiating from the end of the petiole, somethlnj,' like the spread-out fingers of a hand. Tlie veining in this case is therefore described as diijitatt, or rddidtr, ov pdlnuUc. The IcajU't of the clover, on the other hand, is divided exactly in the middle by a single rib (the mith-ih), and from this the veins are given off on e.ach side, so tliat the veining, on the whole, presents the aj^pearance of a feather, and is therefore described as pinnate [penna, a feather). 102. Both simple and compound leaves exhibit these two modes of venation. Of simple piuuately-veined ELEMKNTS OF STKUCTURAL 1A)1ANY. 7b leaves, ilio Beccl), Mulltiii, and Willow supply familiar instances. The ^fallow, ^laple, (riaj)e, Clin ant, and Gooseberry . iLvesinii)le lailiate-veiued leaves. Sweet-lhicr (Fig. l-M, ^loiintain Ash, and Hose have compound ))innate leaves whilst tliose ol Virginia-Creeper (Fig. 100), Fi«. m llorse-Ciiestnut, and Ih-n.p ire C(unj)oun(1 digital e. As has already been pointed out, the leaves ol Mon" cotyledonouH plants are almost invariably straig* veined. 108. In addition to the venation, the description )f a simj^le loaf includes particulars conceniing . (li the general outline, (2) the edge or margin, (8» the point or apex, (1) the base. 104. Outline. As to outline, it will be convenient to consider first the forms assumed by leaves without lobes, and whose margins are therefore more or less conlinuous. Such leaves are of three sorts, viz : those in which both ends of the leaf are alike, those in which the apex is narrow r than the base, and those in which the apex is broader than the base. 105. In the first of these three classes, it is evident tkat any variation in the outline will depend altogether on the relation between the length and tlie breadth of the leaf. When the leaf is extremely narrow in com- parisou with its length, as in tlie Pine, it is (L'i.'u,lar or needle-slut }H'd (Fig. 110). As the? width increases, we pass through the forms known as lineir, vhloiiy, cvfd^ and finally (trl>inilat\ in which the width and length aore nearly, or ^uitc cc^ual (Fig. 11 Ij. lal <\ 74 ELEMKNTS OF STRUCTURAL BOTANY. Linear Oblong Oval Orbicular Fly. 110 Fig. m. 100. lu the sccoiid chiss tlio diHoi-ciit foriiih tuisi? from the varying width o( the base of tlie leaf, and we thus have suliKhilr or airl-nlutpcd (Fig. 11 '2), lan('i'olai'*< orate, and deltoid \e&\CH [Fig. IIM). t r| %:4 1r Lanrcninte Fig. 112. Fig. 113. 107. In the third chiss, aH tlie apu\ expands, we havo a Fi«. 117. Fit,'. 118. FiR. 114. Fit. 115. Fig. 11«. a ELEMENTS OF STHUCTL'RAL BOTANY. 7.". rise we the forms apulhul'dc (l''i^'. Ill), ohhninnhiif (that is, the reverse of hinceoLite) (Fig. llTj), nud ohoratf {Fig. IIG). 108. lu leaves of the second kind we frequently find the hase indented, and then the leaf is conltiti', or ln'cwt-slmped (Fig. 117^. The reverse of this, that is, when the indentation is at tiie apex, is ohcor- date (Fig. 118). The hastate, or spear- sliapcd (Fig. lit)), tifi;iittt(te, or arrow- slin]Hd (Fig. 120), and renifonn, c.r kiuney-shMped (Fig. 121), forms are modific itions of the second class, .vc Fig. I'^O. Fij,'. IJl. Fig. 122. and will ho readily iinderstitod fn>m (lie annexed figures. If tile petiole is attached to any pai t of the u ;der surface of the liMif, instead of to the edge, the leaf is peltate (shield- shai)ed) (Fig. 123). 100. Leaves which are l{d)cd are usually described by stating whether Fig. 123. they are palmately or piunately veir.ed, and, if the former, the number of lobes is generally I' i i 76 ELEMENTS OF STRUCTURAL BOTANY. d '■H m :W ) ' ■ given. If the leaves are very deeply cut, they arc said to be pahtiatifii/ or idnnatij'ul according to tjio veiuiug ( Fig. 124 ) . If the leaf is palmately lobcd, and the lobes at the base are themselves lobed, the leaf is peilate (Fig. 125), be- cause it looks something like a bird's foot. If the lobes of a pinnatifid leaf are themselves lobed, the leaf is l)ij)lnn(i- tijhJ. If the leaf is cut uj) into lino segments, as in Dicoutra, it is said to bo niiilli/id. 1 10. Apex. The principal forms of t]io apex are tlie mncronate (Fig. 122), \-M(.n the leaf is tipped with a sharp Fig. 124. point, as though the midrib were projecting beyond the blade ; cus/ti(l(tle, when the leaf ends abruptly in a very short, but distinctly tapering, point (Fig. 12G) ; <«'ute, or sharp; and obtuse, or blunt. 111. It may happen that the --^M Fig. 125. apex does not end in a i>oint of any kind. If it looks as though the end had been cut off square, it is fruiiratr. If the end is slightly notclicd, but not sufliciently so to warrant the description obcordatc, it is emartfuiate. Fig. 126. 112. Margin. If the margin is not indented in any way, it is said to be cfitirc. If it has sharp teeth, jwint- imj in tlw direction of the apex, it is serrate, and will be coarsely or finely serrate, according to the size of the i::.;.MKNT.i cf sniucii kal botany. 77 Fig. 127. ifctii. SouKtimrs tho edges of Ir.rgo teeth are tlitiuselves finely serrated, and in that case the leaf is dunlin serrate (Fig. Vll). If the teeth point outwards, that is, if the two edges of each tooth are of ^^^ the same length, the leaf / ^ \ is dentate, but if the teeth, ( \ inster-d of being sharp, are rounded, tiio leaf is > \ c/T«rt/(?(Fig. 128). The term «v/v// explains itself. v_J. 113. Base. There are two or three peculiar Fig. i28 modifications of tho bases of simple sessile loaves which are of considerable importance in distinguishing plants. Sometimes a pair of lobes project backwards and cohere on the other side of the stem, so that the stem appears to pass through the leaf. This is the case in our common Bellwort, the leaves of ■which are accordingly described as jwrJoUate (Fig. 129). Sometimes two opposite sessile leaves grow together at the base, and clasp the stem, as in the upper leaves of Honeysuckle, Fig. 120. in the Triosteum, and in one of our species of Eupatorium. Such leaves are said to be cou}iate or con- nate-iKrJ'oUate (Fig. 180). In one of our Everlastings the margin of the leaf is con- tinued on each side below the Pig. .30. Fig. 131. point of insertion, and the lo ^es gi'ow fast to the sides 7b ..j'j.'j.uii'::: of STiiUCiuiui botany. \m ;i m 1^ II ^: o: llic stem, giviog rise to what is called the decarrent lorm (Fig. 131). xho terms by which simple leaves are described are applicable also to the leaflets of compound leaves, to the sepals and petals of flowers, and, in short, to any iiii^t forms. Qcm^' Fig. i;!'2. 1 14. We have already explaired that compound lear/er: are of two forms, pinnate and jxilmate. In the former, the leaflets are arranged on each side o the midrib. There may be a leaflet at the end, in which case the leaf is odd-pinnate, or the jorminal leaflet may be wanting, and then \\\q leaf is •' 'upthj pinnate. In the Pea, the . ic pinnate and terminates in a .idril (Fig. 08). Very frequently Ijhe primary divisions of a pinnate leaf are themselves pinnate, and the whole leaf is then twiec-pinnate (FI^'c 132). If the suhth* vision is continuod throiifj^li aiiotlier stage, "^"y^^ the leal is l^iriee-pinnaie, and so on. '^^ Somctimoe, aa in the leaves of the Tomato, very small leaflets are found between the h.rger ones, and this lorm is described as intcrrupU cdhj^imaic (Firj. 183). Fig. 133, S^u'- i:lemen rs of stkuctui:al dotany. 70 In tlio palmate or digitate forms, the lealKts spread out from the end of the petiole, and, in describing them, it is usual to mention the number of divisions. If there are three, the leaf is tri-foliulato ; if there are five, it is (inhupiefolhdate. 115. In the examination of the Mallow, we found a couple of small leaf-like attachments on the petiole of each leaf, just at the junction with the stem. To these the name stifmhs was given. Leaves which have not these appendages are exstiimlafc, 110. Besides the characters of leaves mentioned above, there remain a few others to be noticed. With regard t^^ their surface, leaves inescnt every gradation from perfect smoothness, as in Wintergreeu, to extreme roughness or wooUiness, as in tlie Mullein. If hairs are entirely absent, the leaf is i/lithroiin ; if present, the degree of hairiness is described by an appropriate ad- verb ; if the leaf is complet 'ly covered, it is rilloffs or ri7/o6'6' ; and if the hairs are on the maigin only, as in mv Clintonia, it is ciliate. Som^^ leaves, like those of Cabbage, have a kind of bloom on the surface, which may be rubbeti oil" with the fingers ; tliis condition is described as «/ltnft'tu(s. 1 17. A few J Lints have anoma- lous leaver. Those of tlie Onion are jiUj'orni. The ritcher llcnt of our Northern swamps has very curious leaves (Fig. l'-^4), appar- ently formed by the turning in and cohesion of the outer edges of cm ordinary loaf, so as to form a 'i^ve, closoc. except at the top, and amed ■ ■ ■! .tt. ^. \ ffl s.'Vj t> v>. ;^^ "^ rS^^- IMAGE EVALUATION TEST TARGET (MT-3) V // *j. >" MPx. / 5r /^A 1.0 I.I li^lllM i^ |5 = >^ IM IIIII2 2 i lis iiiio L25 1 1.4 1.8 1.6 V] <^ /a 'c*l O ^ / M Photographic Sdences Corporation 23 WEST MAIN STREET WEBSTER, NY. 14580 (716) 873-4503 JV "^^ ^ •O' '^ *> ^ <^ i^y Wxp r,^ M 80 ELEME.VTS OF STRUCTURAL liOTAKV. on tlie iimcr surface with bristles pointing oowardc the ))ase of the leaf. 118. Finally, as leaves present an almost infinite variety in their forms, it will often be necessary, in de- scribing them, to combine the terms explained above. For instance, a leaf may not be exactly linear, nor ex- actly lance-shaped, but may approximate to both forms. In such a case the leaf is described as lunce-linear, and so with other forms. The following form of schedule may be used with advantage in writing out descriptions of leaves. T^o 2eavcs — one of Maple and one of Sweet-Brier — are described by way of illustration. If a leaf is compound, the particulars as to outline, margin, apex, base, and surface will have reference to the leaflets. LEAF SCHEDULE. Leaf of Maple. Sweet-Brier. 1. Tosition. Cauline. Cauline. 2. Arraugoment. Opposite. Alternate. 3. Insertion. Petiolate. Petiolate. 4. Stipulation. EKBtipulate. Stipulate. 5. Division. Simple. Odd pinnate, Tleaflott. 6. Venation. Palmate. 7. Outline. Roundish or oval. I 8. Margin. Deeply lobed. Doubly serrate. ELEMENTS OF STRUCTURAL BOTANY. 81 9, Ai)ex. rointed. Acute. 10. ]:;aKc. urdatc. Hardly indented. ' 11. Surface. 1 Glnliroup ibove; ^vhitisb biiiiual ii. Downy abnvo ; covnred Willi glands beneath. CHAPTER XIII. MORPHOLOGY OF FLOWER-LEAVES. THE CALYX. THE CO- HOLLA. THE STAMENS. THE PISTIL. THE FRUIT. THE SEED. GER3IINATION. 119. From an examination of the various forms pre- sented by foliage leaves, we proceed now to those of the floral ones, and we shall first consider t-;'0 chief modifications in the arramjcmcnt of flowers as a whole, to which the term inflorescence is applied. 120. It is found that inflorcscciico proceeds upon two ■V7ell-define4 plans. To understand tliese, let us recur to our specimens of Shepherd's- Purse and Buttercup. You will remember that, in the former, the peduncle continues to lengthen as long as the summer lasts, and new flowers continue to be produced at the upper end. Observe, however, that every one of the flowers is X)roduced in the axil of a bract, that as the stem lengthens new bracts appear, and that there is 7iofloiver on the end of the stem. You will easily understand then, tliat the production of flowers in such a plant is only limited by the close of the season or by the exhaus- tion of the plant. Such inflorescence is therefore called indefinite, or indeterminate, or axillary. It is sometimes also called centripetal, because if the flowers happen to be in a close cluster, r.s are the uppex* It s MP It I S^ ELEMENTS OF STRUCTURAL BOTANV. oneo in Sliepherd's-Piirse, the order of developement is Trom the outbide toivards the centre, 121. If you now look at your Buttercup, you will be at once struck with the difference of plan exhibited. The main axis or stem has a flower on the end of it^ and its further growth is therefore checked. And so in like manner, from the top downwards, the growth of the branches is checked by the production of flowers at their extremities. The mode of inflorescence here displayed is definite, or determinate, or terminal. It is also called centrifugal^ because the developement of the flowers is the reverse of that exhibited in the first mode„ The upper, or, in the case of close clusters, the centred flowers open first. In either mode, if there is but one flower in each axil, or but one flower at the end of each branch, the flowers are said to be solitary. 122. Of indeterminate inflorescence there are several varieties. In Shepherd 's-Purse we have an instance of the raceme, which may be described ac z cluster in which each flower springs from an axil, and IS supported on a pedicel of its own. If the pedicels are absent, and the flowers consequently sessile in t] : axils, the cluster becomes a spikcj of which the common Plantain and the Mullein furnish good examples. The catkins of the Willow (Figs. 63, 64) and Birch, and the spadix of the Indian Turnip (Figs. 80, 81) are also spikes, the former having scaly bracts and the latter a fleshy axis. If you suppose the internodes of a spike to be suppressed, so that the flowers are densely crowded, you will have a head, of which Clover and Button -bush supply instances. If tlie lower pedicels of a raceme are considerably longer than the upper ones, so that all the blossoms are noarly on the same fiLlillElsTS OF STRUCTURAL BOTANY. 83 Fig. 185. 1 ig. 136. level, the cluster is a corymb (Fig. 135). If the flowers in a head were elevated on separate pedicels of the same length, radiating like the ribs of an umbrella, we should have an umbel^ of which the flowers of Geranium and Parsnip (Fig. 49) are examples. A raceme will be compound (Fig. 13G) if, instead of a solitary flower, there is a raceme, in each axV , and a similar remark will apply in the case of the spike, the corymb, and the umbel. 123. The inflorescence of most Grasses is what is called a panicle. This is a compound form, and is usually a kind ot raceme having its primary divisions branched in some irregular manner. If the panicle is 84 ELEMENTS OF SIRULTLRAL BOTAMT. compact, as in the Grape and Lilac, it is what is called a thijrse, 124. Of determinate inflorescence the chief modification is the cijnie. Thia is a rather flat-topped cluster, having something the appearance of a com- pound corymb, but easily distinguished by this peculi- arity, that the central hlossum opens Jirst, then those at the ends of the first set of branches of the cluster, then those on the secondary branches, and so on until the outer buds are reached. The Elder, Dogwood, and St. John's Wort furnish good examples of the cymose ■■•\ Fig. 137. structure. Fig. 137 s'hows a loose open cyme. 125. It has already been pointed out that cauline leaves tend to diminish in size towards the upper part of the stem, where the flowers are found. Such re- duced leaves, containing flowers in their axils, are called bracts. In the case of compound flower-clusters, this term is limited to the leaves on the peduncle, or main stem, the term hractlet being then applied to those oc- curring on the pedicels* or subordinate stems. In tbQ ELEMENTS OF JTRUCTUKAL BOTANY. 85 case of the umbel and the head^ it generally happens that a circle of bracts surrounds the base of the cluster. They are then called, collectively, an involucre, and in tho case of compound clusters a circle of bractlets is called an involucel. Bracts are often so minute as to be reduced to mere scales. From our definition, it will be evident that the spathe surrounding the spadix in Indian Turnip is merely a bract. 126. It has already been stated that the parts of the flower, equally with the foliage-leaves, must be regarded as modifications of the same structure, and some proofs of this similarity of structure were given. We shall now proceed to consider in detail the variations in form asf-umed by these organs. 127. The Calyx. As you are nov; well aware, this term is applied to the outer circle of floral leaves. These are usually green, but not necessarily so ; in some Ex- ogens, and in nearly all Endogens, they are of some other colour. Each division of a calyx is called a sepal, and if the sepals are entn-ely distinct from each other, the calyx is pohjsejKilous ; if they are united in any de- gree, it is 'jamcsepalous. A calyx is rc(jHlar or irregular, according as the sei)als are of the same or diflerent shape and size. 128. In a gamosepalous calyx, if the sepals are not united to the very top, the free portions are known as cahjx-teeth, or, taken collectively, as the limb of the calyx. The united portion, especially if long, as in Willow-herb, is called the calyx-tiihe, and the entrance to the tube its throat. In many plants, particularly those of the Composite Family, the limb of the calyx consists merely of a circle of bristles or soft hairs, 111 I 51 86 ELEMENTS OF STKUCTUEAL BOTANY. J*! and is then described as pappose. In other cases the Umb is quite inconspicuous, and so is said to be obsolete, A calyx which remains after the corolla has disappeared, as in Mallow (Fig. 81), is persistent. If it disappears when the flower opens, as in our Bloodroot, ii is cadii- couSf and if it falls away with the corolla, it is deciduous. We must repeat here, that when calyx and corolla are not both present, the circle which is present is con- sidered to be the calyx, whether green or not. 129. The Corolla. The calyx and corolla, taken together, are called the floral envelopes. When both envelopes are present, the corolla is the inner one ; it is usually, though not invariably, of some other colour than green. Each division of a corolla is called a petal, and the corolla is polt/jwtalous when the jietals are com- pletely disconnected ; but gamopetalous if they are united in any degree, however slight. The terms regular and irregular, applied to the calyx, are applica- able also to the corolla, and the terms used in the description of leaves are applicable to petals. If, however, a petal is narrowed into a long and slender portion towards the base, that portion is known as the claw, whilst the broader upper part is Fig. 138. called the limb (Fig. 138). The leaf- terms are then applicable to the limb. 130. Gamopetalous corollas assume various forms, most of which are described by terms easily understood. The forms assumed depend almost entirely on the shape of the petals which, when united, make up the corolla. If these, taken separately, are linear, and ar^ \ ^ ELEMENTS OF STRUCTURAL BOTANY. 87 \)>l^ uiiited to tlie top, or nearly so, the corolla ^4j;/ will bo tubular (Fig. 189.) If the petals are wedge-shaped, they will by their union produce a fu mid-shaped corolla. (Fig. 140.) In the cumpanidate or bell-shaped form, the enlargement from base to summit is more gradual. If the petals are narrowed abruptly into long claws, the union of the claws into a Fig ud tube and the spreading of the limb at right angles to the tube will produce the salver-shaped form, as in Phlox (Fig. : T 141). The rotate corolla differs from this in having a veru short tube. The corolla of the Potato is rotate. 131. The most* important irretjular gamopetalous corollas are the Ululate, which has been fully described in the examination of the Dandelion, and the labiate, of which we found an example in Fig. i40. Catnip (Fig. 59). The corolla of Turtle-head (Fig. 142) is another example. When a labiate corolla pre- sents a wide opening between the upper and lower lips, it is said to be ringent , if the opening is closed by an rig. 141. Fig. 142. Fig. 143. upward projection of the lower lip, as in Toadflax (Fig. 143), it is said to hQ personate , and the projectim in I. t\ 6b r.:,VMV.ST9> OF STRUCTliriAL liOTANY. tliiscr.30 is knuv/n as iha ^>aiafc, A good m:.;iy corol Ijis Guch as those of Toadflax, Dicontra, Snapdragon, Columbine, and Violet, have protuberaiices or ,y>m':. at the base. In Violet one petal only is spurred ; in > 'oliuubine the whole five are so. 182. The Stamens. As calyx and corolla arc called collectively the floral envelopes, so stamens and pistil are 8X)oken of collectively as the cssoUial orfjans of the flower. The circle of stamens alone is sometimes oalled the andrmiiun. A complete stamen consists of a slender stalk known as the filammt, and a small sac called the anther. Ti e filamont, however, is not un- commonly absent, in wliich case the anther is sessile. As a general thing, the anther consists of two oblong cells with a sort of rib between them called the connec- tive, and that side of the anther which presents a dis- tinctly grooved appearance is the face, the opposite side being the hack. The filament is invariably attached to the connective, and may adhere through the entire length of the latter, in which case the anther is adnate k ! Pig. 144. Fig. 145. Fig. 146. (Fig. 144), or the base of the connective may rest on the end of the filament, a condition described as innate (Fig. 145), or the extremity of the filament may be attached to the middle of the lack of the connective, so that the anther swings about ; it is then said io be '■j(rr€atile (Fig. 14G). In all these cases, if the face of m ELE?IENTS OF STRUCTURAL BOTANY. sd the lui'bcr is turned towards the ccntr of the tiower, it "ij saicL to l)e iiitivrcc; if turned outwards, e.rtrorr..\ 1^3. Tlie cells of anthers commoiil" open along their outer edges to c'lia- cliarge then- poUon (Fig. 147). In most of tho Heaths, liowever, the pol- len is dischr.rged 'lirougl^ a, minute A aperture at tho top Ox each eel) (J?i3'o ji....s).Fig.-:3.i^3^^ r.nd in our F-i :o Cohosh oack ::.', S:5i'^.''":H with a lid cr va^ve near ohe top, T,!::c.: opens n 1 id-id of iiinre (Fig, '.i.iC), Vj6o 6,:Ta2n,: mcsy 'co Gitlici' euurely distinca from ac': Cthor, in which case Jihcy are described ac dian- ch'ouGj 'jpeui.id^injSy ociandroitCy t:c., accordinp; io ohcii ]iumbcr (or, ii 'Jioro than tvronty, t^s indefinite), or tlioy ma; - be united in various wr^ySo i: their anthers r^rc unitec. i:. r^ circle, '.vhile the iiiamcnts are separate (Fisr w.-) they are ^aia to ^o sinifjencrAnm , but it th: iiiamcutc anite to form :, tube, whiL the antherc rcmai::i distmcj, they are said to be monaJeljjhouz (Figc 8'^) ; rl they are in two groups they aro dmddphous (I ig. W,\ " if in threCj tfiadelphous ; if in moro than three, potya- chlphouSo 10^, As to insertion, when stamens are insertec.on the receptacle, they arc liypogynous ; when borne on the calyx, periqiinous ; when borne on the ovary, epirjy- nous ; :.nd it' inserted on the corolla, epipetalouo. They may, howe^'cr, be borne even on the style, as in Orchic. and then they t.rc described as gynandrous. ISO. If the stamens are four in number, e.nd in two -gcXvz of dif!crent lengths, they are said to ])c didyna- mous (Fig. .VG) ; if cin in number, fonr long and twc short, they ?.yc ■^ct'-.xuhrzcLmou^ (lir;. l3), cjndi, naaiiiy. 90 ELEMENTS OF STRUCTURAL BOTANY. if the stamcus arc liiddcn in the tube of a gamopetalous corolla, they are said to be inrlndcd, but if they protrude beyond the tube tlioy arc e.rscrtcd (Fig. 180). 137. The Pistil. This is the name given to the central organ of the llower. It is sometimes also called the (lymt'cium. As in the case of the stamens, the structure of the pistil must be regarded as a modifica- tion of the structure of leaves generally. The pistil may be formed by the folding of a single carpellary loaf as in the Bean (Fig. 159), in which case it is simple ; or it may consist of a number of carpels, either entirely separate from each other, or united together in various ways, in which case it is compoumJ. If the car- pels are entirely distinct, as in Buttercup, the .pistil is aj)oca?'2)oiis ; if they are united in any degree, it ir: sj/ncarpoiis, 188. In our examination of the Marsh Marigold (Figs. 24, 25) wo found an apocarpous pistil of several carpels. We found also that each carpel contained a number of seeds, and that, in every case, tlie seeds were attached to that edge of the carpel which was turned tmvards the centre of the flower^ and that, as the carpels ripened, they invariably split open along that edge, but not along the other, so that the carpel when opened out presented the appearance of a leaf v' li seeds attached to the margins. The inner edge of a simple carpel, to which the seeds are thus attached, is called the ventral suture^ the opposite edge, corresponding to the mid-rib of a leaf, being the dorsal suture. iSOo if we suppose a number of simple carpels to iipproacli each other, and unite in the centre of a flower, it is evident that the pistil so formed would contain as man7 cells as there were carpels, the cells being sepaiv ELEMENTS OF STRL URAL liOJANY. 91 Fig. 151. rig. 150. ated from each other by a do u hie wall, and tliat the seeds would be found arranged about the centre or axis of the pistil ; aLd this is the actual state of thinjL,'s in the Tuhp, whose pistil is formed by the union of three carpels. AVhen the pistil ripens, the double walls sepa- rating the cells split asunder. To these separating walls the name dissepiment or partition is given. 110. But it often happens that though several car- pels unite to form a compound pistil, there is bu,', one cell in the ovary. This is because tlie separate carp ' lary leaves have not been folded before uniting, . Vave been joined edge to e.h'p, or rather with their edges slij, tly turned inwards. In these cases the seeds cannot, of course, L^j in the centre of the ovary, but will be for.iid 071 the IOC Us, at the junction ol the carpels (Figs. 150, 151). In some plants the (.vary is one-celled, and the seeds are ari-anged round a column which rises from the bottom of the cell (Figs. 152, 153). This case is i53. explained by tie early obliteration of the partitions, which must at first liave met in the centre of the cell. 141. In all cases the line or projection to which tVo seeds are attached is called the placenta, and the term placentation has reference to the manner in which the placentas are arranged. In the simple pistil the placentation is manjinal or sutural. In the syncarpouB pistil, if the dissepiments n.et in the centre of the ovary, thu dividing U into snarate cells, the placenta- tion is cerU7'al or axile ; if tho ovarj* i' one-celled : - ! bears the seeds on its walls, jhc placentation ispariciu' Fi 's 1 92 ELEMENTS OP STRUCTURAL BOTANY. i'r and if the seeds are attacl ed to a central column, it is free central. 142. Besides the nnicn of the ovaries there may also be a union of the styles, and even of the stigmas. 143. A very exceptional pistil is found in plants of i-arfW^v. the Pine Family. Here the ovules, in- stead ( f being enclosed in an ovary, are usually simply attached to the inner sur- Fig. 154. face of an open carpellary leaf or scale, the scales forming what is known as a cone (Figs. 154, 155, 156). The plants of this family are hence called rigs. 155, i5i. (jymno-^iwrmous^ or naked- seeded. 144. The Fruit. In coming to tlie consideration of the Fruit, you must for the present lay aside any popu- lar ideas you may have acquired as to the meaning of this term. You will iiud that, in a strict botanical sense, many things are fruits which, in the language of common life, are not so designated. For instance, we hardly speak of a pumpkin or a encumber as fruit, and yet they arc clearly so, according to the botanist's defi- nition of that term. A fruit may be defined to be tlie ripened pistil together io!fh ar,ij other organ, such as the calyx or receptacle, which 7nai/ be adherent to it. This definition will ])erhaps be more clearly understood after a few specimens liave been attentively examined. 145. For an example of the simplest kind of fruit let us revert to our Buttercup. As the cai'pels ripen, the style and stigma are reduced to a mere point. On cutting open one of these carpels when fully ripe, we find it contains a single ^eel, n;)t quite filling the cavity, but attached at one point to the wall of the latter. What you have to guard against, in this ¥ ' ELEMENTS OF STRUCTUIIAL lit/IANV. CJ instance, is the mistake of considering the entire carpel to be merely a seed. It is a seed envel- oped in an outer covering wliich we called the ovary in the early stages of the flower, but which, now that it is ripe, we shall call the pericarp. This pericarp, with the seed which it contains, is tlie fruit. The prin- cipal difference between the fruit of Marsh-Marigold and that of Buttercup is, that, in the former, the peri- carp envelopes several seeds, and, when ripe, sputs open down one side. The fruit of Buttercup does not thus split open. In the Pea, again, the pericarp encloses several seeds, but splits opjn along both margins. The fruits just mentioned all result from the ripening of apocarpous pistils, and they are consequently spoken of as apocarpous fruifs. 14G. In Willow-herb, you will recollect that the calyx tube adheres to the whole surface of the ovary. The fruit in this case, then, must include the calyx. When the ovary ripens, it splits longitudinally into four pieces (Fig. 41), and, as the x^istil was si/?icarpous, so also is the fruit. 147. In the Peach, Plum, Cherry, and sf one-fruits or drupes generally, the seed is enclosed in a hard shell called a putamen. Outside the putamen is a thick layer of pulp, and oriside this, enclosing the whole, is a skin-like covering. In these fruits all outside the seeds is the pericarp. In one respect these stone-fruits resemble the fruit of the Buttercup : they do not split open in order to discharge their seeds. All fruits having this peculiarity are said to be indehiscent, whilst those in which the pericarp opena, or separates into pieces (called valves), ave de- hiscent. I I i u >; ELEMENTS OB* STKUCTtRAL BOTANV 148. In the Apple (Fig. 48) and Pear, the seeds are contained in five cells in the middle of the fruit, and these cells are surrounded by a firm fleshy mass which is an enlargement of the calyx. In fact, the remains of the five calyx- teeth may be readily detected at the end of the apple opposite the stem. As in Willow-herb, the calyx is adherent to the ovary, and therefore calyx and ovary together constitute the pericarp. These fie shy -fruits, or pomes, as they are sometimes called, are of course indehlscent. 149. In the Currant, as in the Apple, you will find the remains of a calyx at the top, so that this fruit, too, is inferior, but the seods, instead of being separated from the mass of the 1 .nit by tough cartilaginous cell- walls, as in the Apple, lie imbedded in the soft juicy pulp. Such a fruit as this is a berry. The Gooseberry and the Grape are other examples. The Pumpkin and other gourds are similar in structure to tlie berry, but besides the soft inner pulp they have also a firm outer layer and a hard rind. The name pepo is generally given to fruits of this sort. 1 50. A Raspberry or Blackberry (Fig. 157) proves, on examination, to be made up of a large number of juicy little drupes, aggre- gated upon a central axis. It cannot, therefore, be a true berry, but may be called Fig. 157. an aggregated fruit. 151. A Strawberry (Fig. 158) is a fruit consisting chiefly of a mass of pulp, hav- ing its surface dotted over with little carpels (achenes) similar to those of the Buttercup. The flesh of the Strawberry '^ ^ Tig. 158. ELEMENTS Oj" STRUCTURAL BOTANY. 96 is simply an enlarged receptacle ; so that this fruit, dso, is not a true berry. 152. The fruit of Sweet-Brier (Fig. '15) consists o:'a red fleshy calyx, lined with a hollo vr receptacle which bears a number of achcncs. This fruit is therefore analogous to that of the Strawberry. In the latter tJie achenes are on the outer surface of a raised receptacld, while, in the former, they r.ro on the inner surface of a hollow receptacle. 153. Tho Gone of the Pine (Fig. 154) is a fruit which diflers in an important respect from all those yet men- tioned, inasmuch as it is the product, not of a single flower, but of as many flowers as there are scales. It may therefore be called a collective or multiijle fruit. The Pine-Apple is another instance of the camo thing. 154. Of dehiscent fruits there are some varieties which receive special names. The fruit of ilie Pea, or Bean (Fig. 159), whox. pericarp splits opo:^ along both margins, la called a legume ; tlif-t of Marsh-Marigold (r'ig. Fig. i£o. 25), which opens Jovn one side only, is a Jollicle. Both of these arc apocar- pous. 155. Any syncarpous fruit, having a dry dehiscent pericarp, is crJled a capside. A long and olonclcr cap- sule, having tv/o cclb ccpr^rated by ii mombranous partition bearing tho seed, and from '.7?uc!i, when ripe, the valvco fall cs^C'j on each side, ic caUccl r. silique fjo ELEMENT!:. OF STRUCT JIIAL BOTANY. I Fig. 100). If, as i. Shepherd's Purse (Fig. 29), the capsule is short and broad, it is ^if^ called a sUlcle. If the capsule opens ^^ hor{z())itaUi/, so that the toj) coDies X/ off like a lid, as in Purslane (Fig. Fig. 101. 161), it is a pyxis. 150. Any dry, one-seeded, indehlscent fruit is called an achene, of which the fruit of Buttercup (Fig. 14) is an exampleo In Wheat the fruit differs from that of Butter- cup in having a closely fitting and adherent pericarp. Such a fruit is called a caryojAsis or grain. A nut is usually syncarpous, with a hard, dry peri- carp. A wintjed fruit, such as that of the Maple (Fig. 102), is called a samara or key. 157. The Seed. The seed has already been de- scribed as the fertilized ovule. It consists of a nucleus, enveloped, as a rule, in two coats. The outer one, which is the most important, is known as the testa. Occasionally an additional outer coat, called an aril, is found. In the Euonymus of Canadian woods, the aril is j)articularly prominent in autumn, owing to its bright scarleii colour. The stalk, by which the seed is attached to the placenta, is i\iQ funiculus, and the scar, formed on the testa where it separates from the seed-stalk, is called the hilum. In the Pea and the Bean this scar is very distinct. 158. Germination of the Seed. When a seed is lightly covered with earth, and supplied with warmth and moisture, it soon begins to swell and soften, owing ho the absorption of water, and presently bursts its Fig. 102. ELEMENTS OP STRUCTURAL BO TAW. 97 coats, either to such a degree as to Hberate the cotyle- dons completely, or so as to permit the escape of the radicle and the plumule. The former immediately takes a downward direction, developing a root from its lower end, and either elongates through its whole length, in which case the cotyVdons are pushed above the surface, as in the Bean, or remains stationary, in which event the cotyledons remain altogether under ground, as in the Pea and in Indian Corn. Before the root is developed, and the little plantlet is thereby enabled to imbibe food from the Eoil, it has to depend for its growth upon a store of nourishment supplied by the parent plant before the seed was cast adrift. The relation of this nourishment to the embryo is different in different seeds. In the Bean and the Pumpkin, for example, it is contained in tlie cotyledons of the embryo itself. But in Indian Corn, as we have already seen, it constitutes the bulk of the seed, the embryo merely occupying a hollow in one side of it. In such cases as the latter, it will be remembered that the term albumen is applied to the nourishing matter, as distinguished from the embryo. 159. As to the number of cotyledons, it may be re^ peated that, as a rule, seeds are either dicotyledonous or monocotyledonous. Some plants of the Pine Fam- ily, however, exhibit a modification of the dicotyledo- nous structure, having several cotyledons, and beii: consequently distinguished a,^ polyeotyledomrus. i 98 ELEMENTS OF STRUCTURAL BOTANY. CHAPTER XV. ON THE MINUTE STRUCTURE OF PLANTS EXOGENOUS AND ENDOGENOUS STEMS FOOD OF PLANTS. 160. Up to this point we have been engaged in observing such particulars of structure in plants as are manifest to the naked eye. It is now time to enquire a little more closely, and find out what- we can about the elementary structure of the different organs. We have all observed how tender and delicate is a little plantlet of any kind just sprouting from the seed; but as time elapses, and the plant developes itself and acquires strength, its substance will, as we know, assume a texture varying with the nature of the plant, either becoming hard and firm and woody, if it is to be a tree or a shrub, or continuing to be soft and compressible as long as it lives, if it is to be an herb. Then, as a rule, the leaves of plants are of quite a different consis- tency from the stems, and the ribs and veins and petioles of foliage leaves are of a firmer texture than the remaining part of them. In all plants, also, the newest portions, both of stem and root, are extremely soft compared with the older parts. It will be our object in this chapter to ascertain, as far as we can, the reason of such differences as these; and to accomplish this, we shall have to call in the aid of a microscope of much higher power than that which has hitherto served our purpose. 161. ir a small bit, taken from a soft stem, be boiled for a while so as to reduce it to a pulp, and a little of this pulp be examined under the microscope, it will be ifoiv-Hi to be entirely composed of more or less rounded r.LJiMENTS OF STRT'CTURAL BOTANY. 09 AND or oval bodies, which are either loosely thrown together (Fig. 163), or are pressed into a more or less compact Fif:'. 1G3. Fi". 164. Fig. 104 (a). mass. In the latter case, owing to mutual pressure they assume a somewhat angular form. These bodies are called cells. They are hollow, and their walls are usually thin and transparent. The entire fabric of every plant, without any exception whatever, is made up of cells ; but as we proceed in our investigation, we shall find that these cells are not all precisely alike, that as they become older they tend, as a rule, to thicken their walls and undergo changes in form, which, t ) a great extent, determine the texture of the plant's ' ubstance. 1G2. A fabric made up of cells is called a tissue. A collection of such cells as we found constituting our pulp, and as we should find constituting the mass of all the soft and new parts of plants, as well as of some hard parts, is called cellular tissue. The cells com- posing cellular tissue vary a great deal in size in different plants, being, as a rule, largest in aquatics, in which they may sometimes bj observed with the naked eye. Ordinarily, however, they are so minute that millions of them find room in a cubic inch of tissue. 163. When young, the walls of the cells are quite unbroken. Each cell is lined with an extremely thin membrane, and a portion of its cavity is occupied by a ! ' i *y ICO ELEMENTS OF STiJT( tTTRAL ROTxXY. soft body called the nucleus. The s[)mcc between the nucleus and the lining of the cell is filled with a thick- ish liquid called protoplasm,, and the microscope re- veals to us the fact that, as long as the cells are liiinfj cells, a circulation or current is constantly kept up in the protoplasm of each. To this curious movement the term cijchms has been applied. As the cells become older, the nature of their contents is altered by the introduction of watery sap, in which other substances are found, notably starch, sugar, chlorophyll (to which leaves owe their green ( clour), and crystals (raphides) of various salts of lime. The substance of wdiich the cell-wall is composed is called cellulose, and is a chemical compound of carbon, hydrogen, and oxygen. In the protoplasm nitrogen is found in addition to the Kihree elements just mentioned. 1G4. The f/rouih of a plant consists in the multiplication jf its cells. Every plant begins its existence with a single c<'ll, and by the repealed division of this, and the growth of the successix e sections, the whole fabric of the plant, whether herb, shru >, or tree, is built up. The division of a cell is accomplished by the formation of a partition across the middle of it, the nucleus having previously separated into two pieces. The partition is formed oat of the lining of the cell. Each half of the cell then enlarges, and, when its full size is attained, divides again, and so on, as long as the cells are living cells. 165. But in order to increase their size, food of some kind is essential. Growing plants supply this to their cells mainly in the form of sap, which is taken in by the root-fibres, and mi.de suitable, or elaboratedf ox assimilated t by chemical action in the plant itsell "Bj Elements of structural botany. 101 a very curious process, the liquids absorbed by the root pass from cell to cell, though each is quite enclosed, until thoy reach the leaves, where the elaboration is performed. The process is carried on under the law, that if two liquids of different density be separated by a thin or porous diaphragm, they will permeate the diaphragm, and change places with greater or less rapidity according to circumstances, the liquid of less density penetrating the diaphragm more rapidly than the other. The cells of plants, as we have said, contain dense liquid matter. The moisture present in the soil, and in contact with the tender root-hairs (which are made up of cells, you will remember), being ( f less den- sity than the contents of the cells, flows into them, and is then passed on from cell to cell on the same princi- T \Q^. The supply of assimilated matter is thus renewed as fast as it is appropriated by the newly divided and growing cells. IGO. If a plant, during its existence, simply multiplies its cells in this way, it can of course only be a mass of cellular tissue as long as it lives. But we see every- where about us plants, such as trees and shrubs, whose stems are extremely firm and enduring. How (^o laese stems differ from those of tender herbs ? How d ) they differ from the soft p*irts of the plants to which they themselves belong ? A moment's consideration will make it evident that, as every plant begins with a single cell, and increases by successive multiplications of it, every part of the plant must at some time have bee. . composed c^ cellular tissue, just as the newer portions are a' ; resent. The ceils of those parts which are no u\ ill ■' I -; M \i% 'i:\ if 102 ELEMENTS OF STRUCTCKAL UoTANV. linger soft must, then, have undergone a change of some kind. Let us try to understand the nature oi this change. It has been stated that the walls of new cells are extremely thin ; as they become older, however, they, as a rule, increase in thickness, owing to deposits of cellulose upon their inner surface. It sometimes happens, indeed, that the deposits are so copious as to almost completely fill up the cavity of the cell. The idea will naturally suggest itself, that this thickening of the walls must impede the passage of the sap, but it is found that the thickening is not uniform, that there are, in fact, regular intervals which remain thin, and that the thin spot in one cell is directly opposite a cor- responding thin spot in the wall of its neighbour. Eventually, however, these altered cells cease to convey sap. 167. The hard parts of plants, then, differ from the Foft parts in the different consistency of their cell-icalls. But they differ also in the form of the cells themselves. In those parts where toughness and strength will be required, as, for ex- ample, in the inner bark, in the stem, and in the frame-work of the leaves, the cells become elongated and their extremities as- sume a tapering form, so that they overlap each other, instead of standing end to end as in ordinary cellular tissue (Fig. 1G5). To this drawing-out process, combined with the Fig. 165. hardening of the walls, is due the firmness of wood generally, and the tissue formed by these modi- fied cells is known as woody tissue. On account of the great relative length of the cells found in the inner £L£MEKT3 OF t liiUCTUIUL IlOTANY. 100 br,rlr, and the consequent toughness conferred upon that part, the tissue formed by them is specially dis- tinguished as bast tissue. Associa«ted with the wood- cells are commonly found others, differing from them chiefly in being larger in diameter, and formed out of rows of short cells, standing end to end, by the disap- pearance of the partitions which separated them. These enlarged cells, produced in this way, are called vcasfh or diictSf and a combinal^ ^ of them is known as vascular tissue. Ducts in- variably show markings of some sort on their walls. The one figured in the margin (Fig. IGG) is a doited duct, the dots being spaces which have not been thickened by deposits of cellulose. Other ducts are spindly marked on their inner surface, but in this case the mark- ings are themselves the thickened part of the ng. mn. cell- wall. It is convenient to speak of the mixture • -f woody and vascular tissue as the Jihro-vascidar si/stem. The name jmrenchjma is commonly applied to ordi- nary cellular tissue, whilst tissue formed of long cells is called proscnchuma. It will be understood, then, that all cells of every description, found entering into the composition of a plant, are only modifications of one original form, the particular form ultimately assumed by the cells depend- ing mainly on the functions to be discharged by that portion of the plant in which the cells occur. N-^' EXOGENOUS AND ENDOGENOUS STEMS. 1C8. It has already been liinted that the two great classes of plants, Dicotyledons and Monocotyledons, differ in the mode of growth of their stem.s. We ehall 104 ELEMENTS OF bTKUcTUBAL BOTANY, c fr: \ now explain Homewliat more in detail the nature of this difference. Bearing in mind the fact stated in the pre- ceding part of the chapter, that old and new parts differ mainly in the sliape of their component cells and the lexture of the cell-walls, it will be found that the dis- tinction between Exogenous aad Endogenous growth depends mostly upon the relative situation of the new cells and the old oi^es — of the paretichyma and the jtrusenchynui. 109. Let us begin witli the stem of a Dicotyledon. i'l;/. 107 shows a section of a young shoot. The whole of the wljite part is cellular tissue, the central portion being the ]>ith. The dark wedge-shaped portions are iibro-vascular bundles, consist- ing mainly of woody tissue, a few vessclsy easily recognised by their larger openings, being interspersed. As the shoot becomes older, these bundles enlarge, nnd others are formed between them, so that the radiating channels of c<^llular tissue wliicli separate them are in the end r( - duccd to much smaller compass than in the earlier stages of growth / (Fig. 108). The narrow channcL are the wrthillari/ raf/s. The cells of which they are composed are flattened by compression. Eventually, a ring of wood is formed, the medullary rays intersecting it in fine lines, a*s the sawed end of almost any log will show. Outside the zone of wood is the barky which at first consists altoge! er of cellular tissue. As the season advances, Fig. 107. Fig. If 8. ELEMENTS OF STRUCTURAL BOTANY. 106 however, loug bafit cells are formed in the uiner part, next the vood, wliicli part. is thereafter specially desig- nated the liber. The outer ring of all, enclosing the whole stem, is the epldermi.i or skin. 170. It is now to be observed that, year after year, the riugs of wood are increased in thickness hy Ji r^ilf'^Ji- cation of their outer cells. Tlieie is, con.se^**^ <'iiev remain un- changed, and the growtn ol tht stem consists in tiie production of new ones. These (which origmate ai the bases of new leaves) being introduced amongst tho older ones, act as wedges, and swell the stem as a whole. THE FOOD OF PLANTS. 172. A word or two is necessary on this subject in addition to what has alreacV been said. The nature of a plant's food may be determined by making a chemical aualysin of the plant's substance. A,: already statod the chemical elemeni,3 found in plants are chiefly fo"** carbon, oxygen hydrogen au(x nitrogen, th3 latter el-^- menl occurring in thi protoplasi . of active ceils. What, then, are the souroer: from which the plan' obtains the«p materiak of its growth ? In the atmosphere there »i^ always prcsen a ga^ knowi: as carbon dioxide, or ca**- bonic acid. This gas, which is a compound of carbo«» and oxygon, i: produced largely in the lung., of animaf anc". by then exhaled. .l\l is readily soluble in water, tha rain-drop, in their passage through the airdissol'-' 'S, diii carry i with them into the soil. Again, where^- - &ni:iia. or vegetabL matter is decaying there iu prr; duoec. a gas called ammonia, a compound of nitrogen and hydrogen, and, likw carbonic acid, readily soluble, so that tin, also is present in rain-water. An ", when i' is consideroc thai .. ver;^- large proportion of th^air con- sists of frou nitrogen, soluble to some extent in water, anc! that 1 elements c" water itself arc oxygen and hydro- gen i' will be y.lc" i-rl that the moisture in th: eftifih coutaii::i a suj^piy of ev< one of the elements .^LB^c^ENTS OF STRUCTURAL BOTANY, 107 IC. chiefly requL-cd b^ the plant. Now it is a matter of common experience ihat, with rare exceptions, a plant will wither and die unless supplied with adequate mois- ture. We therefore come to the conclusion, that at any rate the greater pait of the nourishment of plants is imhibed in liquid form through the roots. The law of endosmose, in accordance with which this imbibing goes on, has already been explained. The sajij as it is called, ascends through the newer tissues, and is at- tracted to the leaves by the constant evaporation going on there, and the consequent thickening of the contents of the cells in those organs. 173. And this leads to the question — How does the water- vapour make its escape from the leaves ? The microscope solves this difficulty for us. A leaf almost always presents one surface towards the sky and the other towards the ground. It is protected on both sides by an epidermis or skin, consisting of very closely packed cells. The side exposed to the sun is almost unbroken, but the lower side is seen, under the microscope, to be perforated by innu- merable little openings, which lead into the body of the leaf. These openings, to which the name stumata, or Uomatcs (Fig. 170) has been given, have th^. power of expanding when moistened by damp air, and contract- ing when dry. By this wonderful contriv- ance, the rate of evaporation is regulated, and a proper balance maintained between the supply at the root aud the loss from the leaves. The stomates, it mav bo noticed, serve also as means whereby carbonic acid may be directly absorbed from the air. In those plants whose leaves float on water the stomates are Fig. 17U. H I " T 108 ELEMENTS OF STRUCTURAL xiOTANY. fn i found on the upper surface, and in vertical leaves they occur pretty equally on both surfaces. Immersed lecvei; are without stomates. 174. The crude sap, then, which ascends into the leaves is concentrated by the evaporation of its super- fluous water. When so concentrated, the action of sun- iii^ht, in connection with the green colouring matter existing in the cells of the leaves, and known as chloro- phyll, decomposes the carbonic acid, contained in the f-ap, into its carbon and oxj^gen. The latter gas issuer from the leaves into the air, whilst the carbon is retained and combined with the r?maining element? to form rlahorated sap, out uf which the substance of new c lis is constructed. 175. It thus appears that the chemical action which goes on in the leaves o:. plants is precisely the reverse of what takes place in the lungs of animals. The latter inhale oxygen, combine it with the carbon of the blood, and exhale the resulting carbonic acid. The former take in carbonic acid, decompose it in the leaves and other green parts, and exhale the oxygen. Plants may there- fore be regarded as purifiers of the air, 17G. It remains to be added, that besides the four substances, carbon, oxygen, hydrogen, and nitrogen, wliich are called the on/anic elements, many others are found in the fabric of plants. When a piece of wood is burnt away, the organic elements disappear, but a quantity of a^/t remains behind. This contains the various mineral substances which the water absorb- ed by the plant has previously dissolved out of the soil, but which it is not necessary to our present purpose to enumerate hero. SLEMfiMTS OF STRUCTURAL BOTANY. 109 CHAPTER XVI. CLASSIFICATION OF PLANTS ACCORDING TO THE NATURAL SYSTEM. 177. Hitherto, our examination of plants has been confined to a few selected specimens, and we have examined these chiefly in order to become acquainted with some variations in the details of growth, as exem- plified by them. Thus, we have found plants which agree in exhibiting two cotyledons in the embryo, and others, again, which are monocotyledonous. Some members of the former group were found to exhibit two sets of floral envelopes, other only one, and others, again, were entirely without these organs. And so on through the various details. "We now set out with the vegetable world before us — a world populated by forms almost infinite in number and variety. If, therefore, our study of these forms is to be carried on to advantage, we shall have to resolve upon some definite plan or system upon which to proceed ; otherwise we shall merely dissipate our energies, and our results will be without meaning. Just as, in our study of language, we find it convenient to classify words into what we call paits of speech, and to divide and subdivide these again, iu order to draw finer distinctions, so, in our study of plants, it will bo necessary to arrange them :\i 110 ELEMENTS OF :.;^rui:AL botany. first of all into comprehensive groups, on the ground of some characteristic possessed hy every member of each group. Just P.S, in Latin, every noun whose genitive case is found to end in m is classed with nouns of the first declension, so in Botany, every plant presenting certain peculiarities will he placed in a group along with all the other plants presenting the same peculiar- ities. 170. Some hints have already been given you as to the kind of rosemblances upon which classification is based. For instance, an immense number of plants arc found to produce seeds with a dicotyledonous embryo, while an immense number of others have monocotyledonou^' embryos. This distinction, there- fore, is so pronounced, that it forms the basis of a divis- ion into two very large groups. Again, a very large number of dicotyledonous plants have their corollas in separate petals ; many others have them united, whilst others again have no petals at all. Here, then, is an opportunity to subdivide the Dicotyledons into poly- petalous. gamopetalous, and apetalous groups. And so we go on, always on the plan that the more widely spread a peculiarity is found to be, the more compre- hensive must be the group based on that peculiarity ; and so it happens, that the smallest groups of all come to depend upon distinctions which are, in many cases, by no means evident, and upon which botanists often find themselves unable to agree. 179. As our divisions and subdivisions will neces- sarily be somewhat numerous, we shall have to devise . a special name for each kind of group, in order to avoid confusion of ideas. We shall, then, to begin with, ^raw a broa4 line of distinction between those plants ELEMENTfJ Cr STR^^CTURAL DOTAIJY. Ill T,hich produce flowers of some kind, and those which dct 7iGtt and to each of these great groups we shall give th^ name Series. We thus h v the Flo' /ering, or, to use the Greek term, Phai- ro^a.T.CUs, Series, and tha Flowerless, or Crypto^ .racU:3, ueries ; or we may sn ak of thrm briefly as Phanercrk^m^ and Crypto- ' ms. Then, leaving the Cryptogams aside foi tne moment, we may break up the Phanerogams into two great Classes, Exogens (or DL^-t^'ledons) and Undoger ; (or Monocotyledon ). for reasons al- ready explained. By far the greater number oi Exogens produce seeds which are enclosed in a pericarp ol some kind ; but there is a remarkable group of plants (repre- sented in Canada only by the Pines and their imme- diate relatives) whicli dispense with the pericarp alto- gether, and whose seeds are consequently naked. So that we can make two bub-Classes of tli,, Tlxogens, on the basis of this difference, and these we ::licM call the Angiospermous Sub-Class, and the Gym::icGpcr- mous (naked-seeded) Sub-Class« The first of these may be grouped in three Divisions, the Pohjpp.tahus^ Gamopetalous, and Apetnlous, and the Endogenj aiso jin three, the Spadkeous, the Petaloideous, and the (jrlumaceoiis, types of which we have already examined :':■» the Marsh Calla (spadiceous), Trillium (pctaloideous)^ and Timothy (glumaceous), and the distinctions between which are sufficiently obvicus. j.he Cryptogams are divided into three great Classes, viz. : Acrog-ns, embracing Ferns, Horse- tails and Club-mosses: Anophytes, embracing Mosses and Liverworts; and ihallopliytes, embracing Lichens, Seaweeds, and Musln-ooms. i I 112 ELEMENTS OP STRUCTURAT. BOTANY. o n H A > So far, then, our classification is a:: follows : / r Sub-class l—Argiosperms Series I. Phanero- gams Class I— Exogens -A Folypetalous Division. Gamnpcialous '' Apctaloufi ( Sub-class 2-r.ynii.()s: liims C Spadiceous Division. Class II.— Endogens-I Pctaloideoxis Division. I L Glnmaccnits Division. /^Class III.— Acrogens. -i Class IV.— AnophytGs. L Class v.— Thallophytes. 'tiSv. Series IT. Cryptogams Each of the Divisions r.j sub-diviucii into number nf Families or Orders ; eacli Order into a number of Genera; and each Genus into Species. A species is the snu^ "^^ all the individual plants wliOc,o resemblances m all essential respects are so great as to warrant the belief that they have sprung from one common s jOck. De Candolle has this statement : " We unite under lie designation or -^ species al) those individuals that mutu- ally bear t > each other so close a resemblance as to allow of our supposing that thry may have proceeded originally from a single being or a single pair." Wc may also speak of each one of these individual plants as a specieso For example, you may say, after finishing the first lesson of this book, that you have examined a species of Buttercup, Mere differences of colour or size are not sufficient to constitute different species. The Balsams of our gardens, for instance, are of various colours, and the plants vary greatly in size, yet they all belong to one species. These minor differences, v/hich arc mainly the result of caro and cultivation, give rise to varieties. These are of great interest to the borticul- ELEMENTS OF STRUCTURAL BOTANY. 113 turist , but the study of si>ecie8 is the great end and aim of the botanist. IHO. Those Species which are considered to resem- ble each other most nearly are grouped into Genera, and the Genera, in like manner, into Orders ; but these particular groupings are more or less artificial, and are subject to continual alteration in con- sequence of our imperfect knowledge. As, year by year, new facts are brought to light, modifications in arrangement take place. In the Classification which constitutes the Second Part of this work, the Divi- sions spoken of above are placed in the order named. In. the Polypetalous Division, those Orders are put first which embrace plants with lujpoaynous stamens and apocarpous pistils, the parts of the flowers boi.i ; consequently separate ; then those with similarly in- serted stamens, but syncarpous pistils ; then those with perigynous stamens ; and, generally, we proceed from plants whose flowers have all their parts separate to those exhibiting more or less cohesion and adhesion^ and finally to those having one or more parts of the flower wanting. 181. In looking up the name of a plant, it will be your object to determine the Genus to which it belongs, and also the Species. The name of every plant consists of two parts : its Genus first, and then its Species. The name of the Genus is a Latin noun, and that of the Species a Latin adjective agreeing with the noun. The Buttercup, for example, which we examined at the outlet, belongs to the Genus Ranuncuhis. In this Genus are included many Species. The particular one Gzamined by us is known as acris ; so that the full name 114 ELEMENTS OF STRUOTtJBAL DOTANY. II of the plant is Ranunculus acris. ^n like manner, the name of the plant popularly called Marsh-Marigold is Calt/i a palust ris. 182. The Key which is prefixed to the Classification will enable you to determine without much difficulty the Order to which a plant belongs, but nothing more. Having satisfied yourselves as to the Order, you must turn to the page on which that Order is described, and, by carefully comparing the descriptions there given with the characters exhibited by your plant, decide upon its Genus, and, in the same manner, upon its Species. 1 1 THE HERBARIUM. Those who are anxious to make the most of their botanical studies will find it of great advantage to gather and preserve specimens for reference. A few hints, therefore, on this subject will not be out of place. It will, of course, be an object to collectors to have their specimens exhibit as many of their natural char- acters as possible, so that, although dried and pressed, there will be no difficulty in recognizing them ; and to this end neatness and care are the first requisites. Specimens should be collected when the plants are in flower, and, if possible, on a dry day, as ^he flowers are then in better condition than if wet. If the plant is small, the whole of it, root and all, should be taken up ; if too large to be treated in this way, a flower and one or two of the leaves (radical as well as cauli e, if these be different,) may be gathered. As many of your specimens will be collected at a dis* tance from home, a close tin box, which may be slung over the shoulder by a strap, should be provided, in which the plants may be kept fresh, particularly if a few drops of water be sprinkled upon them. Perhaps a better way, however, is to carry a portfolio of conveni- ent size — say 15 inches by 10 inches — made of two pieces of stout pasteboard or thin deal, and having a couple of straps with buckles for fastening it together. Between the covers should be placed sheets of blotting paper, or coarse wrapping paper, as many as will allow the specimens to be separated by at least five or six sheets. The advantage of the portfolio is, that th© w 116 ELEilENTd OF STRUCTURAL BOTANY. IN ii m pi plauts may be placed oetvveeu the sheets of blotting paper, and subjected to pressure by means of the straps, as soon as they are gathered. If carried in a box, they should bo transferred to paper as soon as possible. The specimens should be spread out with great care, and the crumpling and doubling of leaves guarded against. The only way to prevent moulding is to place plenty of paper between the plants, and cIkukjc the paper frequently , the frequency depending on the amount of moisture contained in the specimens. From ten days to a fort- night will be found sufficient for the thorough drying of almost any plant you are likely to meet with. Hav- ing made a pile of specimens with paper between them, as directed, they should be placed on a tabic or floor, covered by a Hat board, and subjected to pressure by placing weights on the top ; twenty bricks or so will answer very well. When the specimens are thoroughly dry, the next thing is to mount them, and for this purpose you will require sheets of strong white paper ; a good quality of unruled foolscap, or cheap drawing paper, will be suit- able. The most convenient way of attaching the spec- imen to the paper is to take a sheet of the same size as your paper lay the specimen carefully in the centre, wrong side up, and gum it thoroughly with a very soft brush. Then take the paper to which the plant is to be attached, and lay it carefully on the specimen. You can then lift paper and specimen together, and, by pressing lightly with a soft cloth, ensure complete ad- hesion. To render plants with stout stems additionally secure, make a slit with a penknife through the paper immediately underneath the stem ; then pass a narrow baud of paper round the stem, and thrust both ends of ELEMENTS OF 8TRUCTUKAL BOTANY. 117 the band through the sht. The ends may then be gummed to the back of the sheet. The specimen having been duly mounted, its botan- ical name should be written neatly in the lower right- hand corner, together with the date of its collection, and the locality where found. Of course only one Species should be mounted on each sheet ; and when a sufficient number have been prepared, the Species of the same Genus should be placed in a sheet of larger and coarser paper than that on which the specimens arc mounted, and the name of the Genus should be written outside on the lower corner. Then the Genera of the same Order should be collected in the same manner, and the name of the Order written outside as before. The Orders may then be arranged in accordance witli the classification you may be using, and carefully laid away in a dry place. If a cabinet, with shelves or draw- ers, can be specially devoted to storing the plants, so much the better. INDEX AND GLOSSARY The references are to the Sections, unless Figuies are sfecified. ^Abruptly pinnate, 114. Absorption by roots, '-?, 165. 172. Acaulesceut : apparently without a stem, 18. Accessory fruits: Buch as consist chiefly of an enlargement of some organ, such as t^'' caly: or receptacle, not orgacically united with the pistil, 151, 152. Achenium or Achene, 156 y Achlamydeous : having neither calyx nor corolla, 56 Acicular, Fig. 110. Acrogens, 179. yAcumiiiate : with c long tapering point. Acute: r'Larp-pointed, 110. Adherent: r. term applied to the union of unlike parts; e.g. stamens with corolla, Ac. Adnate (anthers), 132. Adventitious : occurring out of the natural position. Adventitious roots, 86. Adventitious buds, 88. Aerial roots, 86. Aestivation : the folding of the floral envelopes in the bad. Aggregate fruits, 150. Air-plants (epiphytes), 87. Albumen (of the seed) : solid nourishing matter distinct from tbc embryo, 12. Albuminous seeds, 59. /Alternate (leaves), 99. Ament or Catkin, Figs. 63, 64. ^Amplexicaul : clasping a stem. Anatropous : a term applied to ovules when inverted, uo thai; the micropyle is close to the point of attachment. Androecium : the ciroio of stamens collectively, 132. Androus : an ending of adjectives descriptive of stamens, e.g.^ monandrous, polyandrous, Ac. Angiospermous : applied to plants whose seeds are enclosed in an ovary. Annual : a plant which grows from the seed, flowers, and dies, it the same season. Anophytes, 179. Anthc : the essential part of a stamen, containing]; the pollen, 132. Apetalou! : without a corolh ; having onlv on zot ol floral "nvelopes, 20 120 INDBX AND OLOSSABV. Apocarpous: applied to pistils when the carpels are free from each ether. Append ORe : anything attached or added. Appn^ssed : in coutactf but not united. Aquatic : growing in the water, whether completely, or only partially, immersed. Arborescent : resembling a tree. Aril, 157. ^Arrow-shaped, Fig. 120. ^^Bcending : rising upward in a slanting direction ; applied chiefly to weak stems. .Ascending axis : the stem of a plant. ' Ascidium : a pitcher-shaped leaf, Fig. 134. Ashes of plants, 176. Assimilation, 165. ^.Auriculate : same as auricled, having rounded lobes at the base ; applied mostly to leaves. /Awl-shaped, Fig. 112. Awn : a bristle, such as is found on the glumes of many Grasses, Barley for example. ^Axil, 3. ''Axile : relating to the axis. ^Axillary : proceeding from an axil. /Axillary buds, 88. Axillary flowcrS; 120. Axis : the stem and root. baccate : like a berry. Bark, 169. Bast, 167. Bearded : furnished with hairs, like the petals of some Violets, &G. Bell-shaped, 130. ^erry, 149. Biennial : a plant which grows from seed in one season, but pro- duces its seed and dies in the following fieason. Bifoliolate : having two leaflets. Bilabiate: two-lipped, Fig. 142. Bipinnate : twice pinnate, Fig. 132. ^Bipinnatifid : twice pinnatifid, Fig. 123. • Blade : the broad part of a leaf or petal. ^ Bracts, 39, 125. ^Bracteate : subtended by a bract. ^Bractlets : secondary bracts growing on pedicels, 126. "^^Branches : growths from the sides of a stem, originating in axil- lary buds, 3. Breathing-pores (stomates), 173. /Bud : an undeveloped stem or branch. /Bulb, 92. '<^^-\ INDEl AND aLOSSABY. 121 Bnlbiferons : producing bulbs. Balblets, 95. ^Bulbous : like a bulb in shape. Caducous, 128. /Calyx, 6. Cambium layer, 170. ^ampanulate, 130. Capillary : fine and hair-like. Capitulum : same as head, 122. Capsule, 166. Carina, or keel : the two coherent petals in the front of a flower of the Pea kind, Fig. 36. Caryopsis, 156. ^Carpel, 7. Carpellary : relating to a oarpel, e.y , a carpellanj I aj\ &c. Cartilaginous: tough. ^Catkin, Figs. 63, 64. Caulescent : with an eyident stem. Caulicle : another name for the radicle. ^Cauline: relating to the stem, e.g., caulinc leaves, &g., 4. Cell : the hollow in the anther, which contains the pollen. See also 161. Cell-multiplication, 164. Cellular tissue, 162. Cellulose, 163. Centrifugal inflorescence, 121. Centripetal ii) florescence, 120. Chalaza : the part of an o\ule where the coats are united to the nucleus. Chlorophyll, 163, 174. Ciliate, 116. /Circinate : curled up like the young frond of a Fern. Circulation in cells, 163. CircumcisFile: opening like a pyxis. Fig. 161. Classification, 177. Claw (of a petal), 40, 129. ^Climbit g Btems, 90. ' Club-shaped: with the lower part nioie slender than the upper, as th- style of Dog's-tooth Violet, Fig. 73. Cohesent: a term applied to the union of like parts, 26. Cohesion, 26. Collerm, or reck : the junction of the si^m and root. Coll active fruits, 153. Column, 72. Coma : a tuft of nairs, such as that oc the seed of Dandelioc, Fig. 66. Complete, 8. Compound, or Composite, f owors, iS). U I22 tNDEX AND OLOSSABT. pi ^Compounu kri, 100. yCompoune rpike, corymb, Ac, 122. Cone, 14Co ^XoniforouE : bearing cones. xLonnate : growi? together, ^^onnate-perfoliate, Fig. 130. Connective, 13*2. Convolute : rolled inwards from one edge. /Cordate, 108. Corm, 66. .Corolla, 6. Corymb, Fig. 135. Corymbose : like a corymb. Cotyledons, 68. / Creeping, 90. /Crenate, Fig. 128. ^^ruciform : cross-shaped, as the flowers of Shepherds Purse, &c. Crude Bap, 174. Cryptogams, 179. Culm, 90. Cunoatc : wedpe-ahaped. Cusi^idate, Fig. 126. "'Cyclocic, 163. Cyme, 124. ^C;;i.iosfe: hke a cyme. Decandrour : with ten separate stamens. Deciduous 5. Deooiapoun : applied to leaves whose blades are divided and subdivided. Decumbent: applied to stems which lie on the ground but turn upward at the extremity. /-Decurrent, Fig. 131. Decussate : applied to the arrangement of leaves, when successive pairs of opposite leaves are at right angles, as iu the plants of the Mint family. Definite inflorescence, ICl. Deflexed : bent down. Dehiscent, 147. '' Dehiscence of anthers, Figs. 147, 148. 149. Deliquescent : applied to stems which dissolve into branches. /Deltoid, 146. ^entate, 112. Depauperate : innaturally small. Repressed : flattened down. DeBCcnding axic : the root, 33, "i Determinate iufloresccnco, ICl. DiadclpbouB : opplied to rjtc.ncn;:, C>C<. Piandrous : witr :v;o sepaiT.t^ ptr.ineu'j. INDEX AND GLOSSARY. 123 ^Dichlamydeous : having both sets of floral envelopes. Dicotyledonous, 58. ' Dicotyledons, 59. ' Didynamous (stamens). 50 Digitate, 101. Dioecious, 56. Disk : iu flowers of the Composite Family, the centre of the head as distinguished from the border ; a fleshy enlargement of the receptacle of a flower. Dissected : finely cut. Dissepiment, 139. Distinct: not coherent, (see Coherent). Divergent : separating from one another. Dodecandrous : with twelve distinct stamens. ^ Dorsal suture, 138. Dotted ducts, Fig. 166. Doable flowers : abnormal flowera in which stamens and carpels have been transformed into petals. •^Do'.vny : covered with soft hairs. ^vDrupe, 147. Drupelet, a little drupe. Ducts, 167. 1 i Earthy constituents of plants, 176. Elaborated sap, 174. EleL-^.cntary constituents of plants, 176. Ulementary structure, 160. ^Elliptical : same as oval, 105. ^ Emarginate, 111. Embryo, 12. Embryo-sac, 16. Emersed : raised above the surface of water. , Endocarp : " When the wall&of a pericarp form !iwo or more lay- ers f dissimilar texture, the outer layer is called the Epicarp, the : iiiddle one J/^socarp, and the iimcrmost Endocarp/' — Gray. Endogen, 81. Endogenous growth, 171. Endosmose, 172, 165. Enneandrous : with nine distinct stamens. Entire, 112. Ephemerf : last: ' one day only. Epicalyx, 33. Epicarp : eee Endocarp. Epidermis, I'oJ. Epigynous : inserted on the ovary, 46. Epipetalous : inserted on the corolla, 47f Epiphytes, 87. Ei^uitaut (leaves), 98, / / 1^4 nvyiir: ;.3HIj c:lossary. i^D^ential organB, 17. Evergreen : retaining foliage during winter. Exalbuminous, 69. Excurrent: said of main stems which are distinct, and well- markeJ to the top, as in the Pine and Fir ; the reverse of deliquescent. Exhalation, 175, 173. Exogen, 60. Exogenous growth, 169. Exserttnl protruding, 136. ^Exstipulatc, 115. Extrors^, 132. !;■• /Fascicle: a close bundle, either of leaves or flowora. i'ascicled roots, 85. feather-veined : same as pinnately-veined, 101. Fertile flowe. '3 Fertilization, . /Fibrous thread , 2. Fibro-vascular sysioin, 167. /Filament, 6. ^yi^iliform, 117. ^ Fimbriate : fringed. Fleshy fruits, 148. Flora : a description of the plants of a district ; a collective name for the whole of the species of a district. Floral envelopes, 14. Floret, 48. riower : the part of a phanerogamous plant in which the stamens and pistil are situated. / Flower-leaves, 11. Flowering plants, 179. riowcrless plants, 179. I'oliaceous : like a leaf in appearance. ^'oliolato : having leaflets. I'ollicle, 154. .I?ree, 6. rruit, 144. Fugacious : falling away early. •Funiculus, 157. /Funnel-shaped, Fig. 140. Furcate: forked, ^^usiform : same as spindle-shaped, 85. GrJea : an arching petal or sepal, as the two upper ones in Catmp^ Camop. iloua, C3. /Crjnopetalours, 120. / C iOioBepaloua, 127. *«.«<,'• INr^fiJ: AND GLOSSARY. l*i\J I. Df z' Genera : plural o* genus. Genus, 179. Germ : same as embryo. Germination, 150. Gibbous : swollen on ono side. Glabrous, 116. Gladiate : sword-shaped. Glands ", applied generally ^o cells or huirs on the surfaces of plants, in which resinous or oily matters are secreted ; but the term is also used to describe any projection, the use of which is not clear. Glandular : bearing glands. Glaucou^ 116. Globose : like a globe or sphere. Glumaceous : bearing or resembling glumes. Glumes, 75. Gourd, 149. Grain, 156. Granules : particles. Gymnospermous, 143. GymnospermS; 179. Gynoecium, 137. Gynandrous, 135. i 16 IS Habitat : a term applied to the region most tavourabie to the growth of a plant : the place where it grows naturally. /Hairs, 116. /Hairy, 4. Halberd-shaped, Fig. 119, /Hastate. Fig. 119. Head, 122. /Heart-shaped, 108. Heptandrous : with seven distinct stamens. Herb, 89. Herbaceous, 89. Herbarium : a botanist's collection of dried plants. Hexandrous : with six distinct stamens,. Hilum, 157. /Hirsute : rough with hairs. Hispid : covered with stiff hairs. Hoary : densely covered with fine grayish hairs Hortus siccus : same as herbarium. Hybrids : plants resulting from the crossing o. nearly related species. Hypogynous. 135. Imbricate : overlapping like shingles on a roof. Immersed : wholly under water. Imperfect, 63. 126 INDEX AND GLOSSAHIfo if? il . Included, 136. ^Incomplete, 19. ^Incurved (petals) Fig. 60. Indefinite, 20, 134. Indefinite inflorescence, 120. ^udebiscent, 147. Indeterminate iuflcrescence, 120. Indigenous : naturally growing in a country. Inferior : underneath ; farthest from the axis ; the ovary is inferior when the calyx adheres to it throughout ; the calyx is inferior when free from the ovary. ^Inflorescence, 119. Innate, 132. /-Inserted : attached to. • /Insertion : the point, or manner, of attachment. /Intornodes, 4, ^ Interruptedly pinnate, Fig. 138. Introrse, 132. ^ Involucel, 125. /Involucre, 125. /^Involute : roiled inwards from both edges. /-Irregular, 35. Isomerous ■• Imvirfj the parts equal in number. y Joints : a name sometimes given to the nodes of a stem. Keel, see Carina. Kernel, 16. Key-fruit, 156. ^idney-shaped. Fig. 121. Labellnm (or lip), 71. /Labiate, 60. /x Lanceolate, Fig. 113. ^Leaf, 97. Leaf-arrangement, 99. Leaf -green, Bee Chlorophyll. /Leaflet, 100. y Leafstalk, 4. /Legume, 164. .Leguminous : producing or relating to legumes. Liber, 169. Ligneous: woody. ^ Ligulate, 131. y: Ligule: a Btrap-ehaped corolla n Grasses, a scale-iiko projec- tion between the blade of a leaf and the sheath. Limb, 129, 130. '^Lip, 866 Labellnm. Linear, Fig. 111. fi INDEX AND GLOSSARY. 127 ^Lobe, 4, 100. Locuiicidal (dehiscence) : eplittiug midway between the partitions. Loment : a jointed legume. / Lyrate : pinnately-lobed, with the terminal lobe much larger than the others. y IS ilyx Marcescent : withering persistent. Marginal : relating to the margin. Markings (on cells) , 167. Medullary rays, 169. ^Membranous : thin, like a membrane. j.Mesocarp: see Eudocarp. Micropyle, 16. ^Midrib, 101. Monadelphous, 134. Monandrous: with a single stanipn, 72. ^Monochlamydeous : with only one set of floral envelopes. ^ Monocotyledonous, 80. ^Monocotyledons, 81. Monoecious, 63. Morphology, 82. >.Mu,.onate, 110. Multifid, 109. Multiple fruits, 153. 30- / Naked flowers : those which are destitute of calyx and corolla. Naked seeds . those not enclosed in an ovary, 143. -Napiform, 85. ^Natural system of classification, 177, &c. Naturalized ; introduced from other countries, but growing spon- taneously from seed. Neck, see CoUum. Nectary : that in which nectar is secreted. Needle-shaped, Fig. 110. Net-veined, 4. Neutral flowers : those having neither stamens nor pistil. ^Nodding : hanging with the top downwards, like the flower in Fig. 72. ^Nodo, 4. Normal : regular; according to rule. ^Nucleus (of an ovule), 16, 157 ; (of a cell), 163. / Nut, 156. Nutlet : a small nut, or nut-like body, 60. ^bcordate, 108. / Oblanceolate, 107. Oblique : having the sides unequal. Obliteration (of partitions), 140, ^Oblong, 106. 128 INDEX AND OLOSSABY. Obovate, 107o 'Obtuse, 110. Gchrea : a tube formed by the union of both edges of a pair of ctipules. /Ochreate : Laving ochreae. Octandrous : having eight separate stamens. OUset: a short, prostrate branch, rooting at the end. /Opposite, 99. ^I'bicular, 105c Orders, 179. Organic elements, 176. Organc; : the parts or members of a living body. Organs Oi Kerroduction : the parts of the flower. Organs ci Vegetation : root, stem, and leaves. Orthotropous : applied to ovules when straight, so that the micro. pyle is as far as possible from the »>oint of attachment. /Oval, 105, /Ovaiy, 7. ^,Ovate, 106. ' Ovoid : egg-shaped. ^Ovule, 7. xPalate, 131. Palet, 75. ^ Palmate, 101. /Palmately-lobed, 109. /Palmatifid, 109. Panicle, 123. Papilionaceous, 35 Pappo-e, 128. Pappus : a circle of bristles or hairs representing the limb of th? calyx in flowers of the Composite Family, 48. parallel-veined : same as straight-veined, 62. Parasites, 87. Parenchyma, 167. Parietal : on the walls, 141. Parted : almost completely cut through. Pectinate : pinnatifid with lobes like the teeth of a comb. Pedate, Fig. 125. '/Pedicel, 27. •Peduncle, 5. ^Peltate, Fig. 123. ' Pentandrous : with five distinct stamens. /Pepo, 149. Perennial : a plant which continues to grow year after year. Perfect : having both stamens and pistil. ^Perfoliate, 113. ^Perianth, 63. Pericarp, 145. . • .. : ' • i., INDEX AND OLOSSABY VAd P^rigynous, 36. Persistent, 32. ^x'ersonate, 131. JPetal, 5. ^etiolate : having petioles. -Petiole, 4. Phanerogamous or PhcBnogamous, 179. Pilose : having long soft hairs. Pinna : a primary division of a pinnatHy compound leaf. ^Pinnate, 101. ^Pinnately-lobed, 109. ^Pinnatifid, 109. Pinnule : a secondary division of a pinnately compound leaf, pistil, 137, 7. ^P:,5tillate : having a pistil, 63. Pitoher-shaped (leaf), Fi^'. 134. Pith, 169. ^ Placenta, 141. Placentation, 141. Plumose : feathery. Plumule, 58. Pod : a dehiscent frail. Pollen, 6. -^PollPn-tube, 16. Pollinia : pollen-masses. Fig. 87. Polyadelphous, 184. Polyandrous : with numerous distinct stamens. Polycotyledonous, 159. Polygamous: having perfect as well as imperfect flowers, / Polypetalous : having separate petals. y Polysepalous : having separate sepals. Pome. 148. Posterior : next the axis. PrBBfl' rati'^n, see Estivation. Prrofoliation : the disposition of leaves in the b'?d. ^Prickles, 96. Procumbent : lying on the groand, Prosenchyma, 167. /Prostrate, 90. Protoplasm, 163. PuV'^'-cent : covered with fine down. Pimotute : having transparent dots, like the ler^ves of bt. John's Wort. .• accimcn, 147. PyxiB, 155. ..•' Quinquefoliolate : having five Idaflets, xBaceme, 128. ii? 130 INDEX AND GLOSSABY. ^Racemose : like a raceme. xRaohis: nn axis. Radiate, 101. /Radical : pertaining to the root. /Radical leaves, 4. Radicle, 58. Raphides, 163. Ray : the marginal florets of a comp'^ "He flower, as distinguished from the d'sk. Ileceptaclo, 8. Recurved : curved backwards. Reflexed : bent backwards. , Regular : with parts of the same size and shape. ^ Reniform, Fig. 121. Reticulated : netted. ^Retuse : slightly notched at the apex. /Revolute : rolled back. yRhizome, 91. Pibs, 101. Ringent, 131. Root, 2, 83. Root-hairs, 165. Rootlet, 2. Rootstock, 91. ^Rotate, 130. Rotation in cells, 163. Rudimentary : imperfectly developed. Rugose : wrinkled. .Runcinate: with teeth pointing backwards, as in the loaf Dandelion. /Runner, 90. h i / ^Sagittate, Fig. 120. Salver-shaped, Fig. 14 i Samara, Fig. 162. Sap, 172, 174. Saroocarp : the flesh of a drupe. Scabrous : rough. Scandent: climbing. Scape, 19. Scar, 157. Scion : a young shoot. Seed, 17, 157, 158. Seed-vessel, see Ovary. ^Sepal, 6. Septicidal (dehiscence) : splitting open along ih partitions.e Septum : a partition. Series, 179. Serrate, 112 INDEX AND GLOSSARY. 181 ed ^cui yj.- ,C essile, 4. etaceous : like a bristle. y Sheath : •. tuho Buirounding a Btem, 62. Sheathing : surrounding like a ebeath. Shield-shaped, see Peltate. Shoot : a newly formed branch. Shrub, 89. ^ Silicle, 155. Silique, 155. C Simple (leaves), 100; (pistil), 137. •Sinunte : wavy on the margin. ^Solitary, 121. Spadiceous, 179. Spadix, 69. Spathe, 69. /Spathulate, 107. Species, 179. Spike, il2. Spikelet, a secondary spike. /Spindle-shaped, 85. Spine, 96. Spiral markings, 167. ^ Spores : the reproductive bodies in CrypI ogams which correspond to the seeds of Phanerogams. /Spur, 131. ^Stamen, 6, 132. Staniinate (flower) : having no pistil, but only stamens, i^^ Standard : the broad upper petal of a papilionaceous corolla. 'Stem, 3, 88. Stemless, 18. ^Sterile (flower) : having no pistil. Stigma, 7. Stigmatic : bearing the stigma. Stipulate: having stipules, 115. .Stipule, 31, 115. Stolon : L. short branch which droops to the ground and takes root. Dtomate, 173, Stone, see Putamen. ,Stone-fruit, see Drupe. ^Strap-shaped, see Ligulate. Striate : marked lengthwise with lines or furrows. Strobile : same as Cone. Style, 7. /Bub-class, 179. •Subulate, Fig. 112 Succulent : juicy ; fleshy. Sucker : an underground branch, at length emerging and form- ing a stem. / /t ■!■ 183 INDEX AND GLOSSARY. / Superior, 7, 37, 44. Buppression : absence of parts. Suspended : hung from above. Suture, 138. Symmetrical, 42. Syncarpous, 20. Syngeuesious, 47. m / ^Tap-root, 84. Te(th (of calyx), 32. Tendril, 90. Terete : cylindrical. /Terminal: at the end of a stem or branch. Teruate : in threes. Testa, 157. TetradynamouB, 28, 136. Tetrandrous : having four distinct stamens. Thalamiflorous : having the stamens inserted on the receptacle. Thalamus : the receptacle. /Thread-shaped, see Filiform. /Throat (of cilyx), 128. Thorn, see Spine. ^Thyrse, 123. Tissue, 162. Tomentose : woolly. Toothed, see Dentate, 112. Torus : same as receptaolf. Tree, 89. Triadelphous, 134. Triaudrous : having three distinct stameQI* Triennial : lasting three years. Trifoliolate : having three leaflets. Truncate, 111. Trunk : the main stem. Tube, 84, 128, Tuber, 91. Tuberous : like a tuber. Tunicated, 92. , ^Twining, 90. ^Tv^o lipped, see Labiate, 60. /Umbel, 122. ^Umbellet : a secondary umbel. Ungaiculate : having a claw. Valvate : edge to edge, but not oyerlapping. ^ Valve, 41, 133, 147. Valved : having valves. Varieties, 179. A e. INDKX AND GLOSSARY. Vascular tissue, lG7. X Veins : the finer parts of the framework of « leaf. /Venation, 101. mwm. ^ Ventral suture, 138. "^Vernation, flame as Pra>foliatiou VersatilA, 132. Vertical loaves, 98. Verticillate, 99. Vessels, 167. •Villose, 116. 133 i tl I. i 11 vi APPENDIX. !R' ^^krtions from S^amiuutbn ^ap^rs. UNIVERSITY OF TORONTO. 1. Define suckers, stolons, ofi^sets, runners, tendrils, thorns, and prickles, describing their respective origins and uses, and giving examples of plants in which they occur 2. What are the functions of leaves ? Describe the iifferent kinds of compound leaves. 8. What is meant by inflorescence ? Describe th§ different kinds of flower-clusters, giving an example of each. 4. Mention and explain the terms applied to the various modes of insertion of stamens. 6. How are fruits classified ? What are multiple or collective fruits ? Give examples. 6. Relate the differences in structure between endo- genous and exogenous stems. Describe their respective modes of growth. 7. What is the food of plants ? how do they obtain it ? and how do they make use of it ? 8. Describe the component parts of a simple flower. How is reproduction effected ? 9. Describe the anatomical structure of a leaf, and the formation and office of leaf-stomata. 10. Explain the consequences of flowering upon the health of a plant, and shew how these effects are reme- died in different climates. What practical bearing has this upon horticulture ? 11. Trace the development of a carpel from a leaf. Describe the different forms assumed by placentaB in 18i APPBNDIX. 136 compound ovarieB, and explain the origin of these variations. 12. Mention the principal modes in which ])ollen gains access to the stigma. What are hybrid plants, and how are they perpetuated ? 18. Describe the anatomy of a leaf. "What are stomata '? 14. What is the placenta in a seed vessel ? Describe the different modes of placentation. Shew how the varieties! of placentation agree with the "altered-leaf theory " vof the pistil. 15. Give the cliaracters of the Composites. How is the order subdivided ? Describe the composite flower, and mention some of the common Canadian examples of this order. 16. Give the peculiarities of Endogens in seed-leaf, leaf, and stem. Subdivide the class. Describe shortly the orders Araceae and Gramiueae. 17. Describe the wall of a seed-vessel, and notice its varieties of form. 18. What is meant by the dehiscence of a capsule ? Show the different modes in Wxiich pods dehisce, and give examples of each. 19. Give the characters and orders of Gymnosper- mous Exogens. 20. Give the characters of RauunculacesB. Describe shortly some of the principal plants of the order. 21. Give some account of the special forms which the leaves of plants assume. 22. What are stipules ? What their size and shape ? 28. What la meant by Imperfect, Incomplete, and Un symmetrical flowers respectively ? 24. Describe Papilionaceous and Labiate corollas. 25. Write notes on Abortive Orgaixs, Gymnosper- mous Pistil, and Pollen Grannie. 26. Distinguish between the esr 3ntial and ncn-esseu- tial materials found in plants, and notice the non-es- sential. 27. What if J vegetable growth ? Illustrate by a ref •I 186 APPENDIX. r S*) '1 r. i :i'n m it. ft ;■ erence to the pollen granule in its fertilization of the ovary. 28. What is an axil ? What is the pappus ? 29. What are the cotyledons ? What is their func- tion, and what their value in systematic Botany ? 80. Distinguish between Epiphytes and Parasites; Describe their respective modes of growth, and give ex- amples of each. 81. What is the difference between roots and subter- ranean branches ? Define rhizoma, tuber, corm, and bulb, giving examples of each. How does a potato differ botanically from a sweet-potato ? 82. Describe the calyx and corolla ; y .c modifica- tions of parts take place in double flowers */ 83. What is a fruit in Botany ? Explain the struct- ure of an apple, grape, almond, strawberry, fig, and pineapple. 84. What organs appear in the more perfect plants ? In what two divisions are they comprised ? 85. Weak climbing stems distinguished according to the mode in which they support themselves, the direc- tion of their growth, the nature of their clasping organs. 86. Structure and parts of a leaf : What is most im- portant in their study ? Give the leading divisions, and mention what secondary distinctions are required in specific description ? 87. Function of the flower : its origin : its essential and accessory parts : names of the circles and their component organs: circumstances which explain the differences among flowers. 88. Parts of the fully formed ovule and distinctions founded on their relative position. 89. Sub- kingdoms and classes of the vegetable king- dom. SECOND CLASS TEACHERS' CERTIFICATES, PROVINCE OF ONTARIO. 1. Name the parts of the pistil and stamens of a flower and give their uses, .iPPENDIX. lar How are leaves constituents of ^ 2. What are Perennial plants ? Describe their mode of life. 3. '* There are two great classes of stems, which differ in the way the woody part is arranged in the cellular tissue." Fully explain this. 4. Describe the functions of.leaves. classified as to their veinmj / 6. Name and describe the organic plants. 6. Name the organs of reproduction in plants, and describe their functions. 7. Give, and fully describe, the principal parts of t}ie flower. 8. What are the different narts of a plant ? Describe the functions of each part. 9. State all the ways by which an Exogenous stem may be distinguished from an Endogenous. 10. Describe the functions of leaves. What is the cause of their fail in autumn ? Draw and describe a maple leaf. 11. Name the different parts of a flower, and describe the use of each part. Draw a diagram showing a sta- men and a pistil and the parts of each. 12. What is the fruit ? Why do some fruits fall from the stem more easily than others ? 13. Of what does the food of plants consist ? In what forms and by what organs is it taken up, and how is it asssimilated ? Name the substances inhaled and those exhaled by plants, and the uses of each in the economy of nature. 14. Describe fully (1) the plant in Vegetation ; (2) the plant in Reproduction. 15. Describe Fibrous roots, Fleshy roots, and differ- ent kinds of Tap-root. 16. Describe the structure and veining of leaves. 17. "The nourishment which the mother plant pro- vides in the seed is not always stored up in the embryo," Explain and illustrate. " 8. Describe the various modes in which Perennials 38 APPENDIX. R*i it 4 iv I "provide a stock of nourishment to begin the new growth." 19. Describe fully the organs of reproduction in a plant. Describe the process of germination. 20. What are the parts of a flower ? Give illustra- tions by diagram, with a full description. 21. Name and describe the principal sorts of flowers. 22. What elementary substances should the soil con- tain for the nourishment of plants ? 23. How are plants nourished before and after appearing above ground ? 24. Tell what vou know about the various forms of the calyx and the corolla. 25. Explain the terms Cotyledon, Pinnate, Eoot- stock. Filament, and Radicle. 2G. Explain the terms Papilionaceous, Cruciferous, Silique, and Syngenesious ; and in each case name a family in tlie description of which the term under con- sideration may be properly applied. 27. Give the characters of the Rose family. 28. Describe the various modes in which biennials store up nourishment during their first season. 29. Explain the meaning of the terms Sepal, Bract, Raceme, and Stipule. Describe minutely the Stamen and the Pistil, and give the names applied to their j)arts. 30. Are the portions of the onion, the potato, and the turnip which are capable of preservation through the winter, equally entitled to the name of roots ? Give reasons for vour answer. j' I If! FIRST CLASS CERTIFICATES. 1. What are the cotyledons^ Describe their func- tions, kc. State their value in systematic botany. 2. Describe the difterence in structure and modes ol growth of exogenous and endogenous stems. 8. Describe the circulation in plants. " In the aoi of making vegetable matter, plants purify the air for animals." Explain this fully. APPENDIX. 139 4. What are Plioenogamous plants ? Define Kaceme, / Corymb, Head, Panicle, Ament. 5. Give the characters of (a) The classes Exogeng and Endogens ; (h) The Mint and Lily famihes. 6. To what family do the Cedar, Clover. Mustard, and Dandelion respectively belong ? 7. Why does a botanist consider the tuber of the po- tato an underground stem ? 8. Give the philosophical explanation of the nature of a flower considered as to the origin and correspond- ences of its different parts. / 9. Draw a spathulate, an obcordate, a truncate, a palmately-divided and an odd pinnate leaf. 10. Explain the constitution of a pome or apple- fruit. 11. What organs appear in the more perfect plants, and in what divisions are they comprised ? 12. Give the function of the flower, its origin, and its essential and accessory parts. 13. Describe the nature and chief varieties of roots, and .iistinguish between them and underground stems. 11. '• As to the Apex or Point letves are Pointed, ' Acute, Obtuse, Truncate, Ketuse, Emarginate, Obcor- date, Cuspidate, Mucronate." Sketch these different forms. 15. " There is no separate set of vessels, and no open tubes for the sap to rise through in an unbroken stream, in the way people generally suppose." Comment on this passage. 16. The great series of Flowering Plants is divided into two classes. Describe these classes. 17. Give the chief characteristics of the order criici- fercE (^Cress Family j, and name some common exam- ples of this order. 18. State the difference between definite and indefin- ite inflorescence, and give examples of the latter. 19. Of what does the food of plants consist ? in what form is it found in tlie soil ? How is it introduced into the plant ? What inference may be drawn respecting the culture of the plant ? * 140 AI»I>END1X. lit 5J0. Distinguish weak climbing stems according to the mode in which they support themselves, the direc- tion of their growth, and the nature of their clasping organs. 21. Name the three classes of Flowerless Plants, and give an example of each. 22. Explain the terms Spore, Capsule, Bract, Stip- ule, Albumen, and Epiphyte. 28. What are tendrils, and of what organs are they supposed to be modifications ? 24. Give the characters of the Cress Family, and name as many plants belonging to it as you can. 25. Tell what you know about the minute structure and the chemical composition of vegetable tissue. 26. Describe the origin of the different kinds of pla- centas ; and of the different parts of the fruit of the plum, the oak, and the maple. 27. Describe fully the process by which it is sup- posed that water is carried up from the roots of plants. 28. Give the meaning of the terms stomate^ indehis- cetd, thyrse, glume, pyxis. Distinguish epiphytes from parasites. 29. Describe any plant you have examined ; if you can, tabulate your description. 80. Name all the families of monopetalous dicotyle- dons which you remember, and give the characters of any one of them. McGILL UNIVERSITY. 1. Describe the germination of a plant. 2. Explain the differences in the structure of the embryo. 8. Explain the functions of the iioot. 4. Describe the structures in a leaf, ana expiain their action on the air. 5. Mention the several parts of the stamen and the pistil, and explain their uses. 6. Describe an Achene, a Samara, a Drupe and a Sili^ue. • APPENDIX. 141 7. Describe the differences in the stems of Exogens and Endogens, and the relations of these to the other parts of the plant and to classification. 8. Explain the terms Genera, Species, Order. 9. What is an excurrent stem, an axillary bud, bud scales ? 10. Explain the terms primoraial utricle, parenchymay protoplasm^ as used in Botany. 11. What are the functions of the nucleus in a living cell? 12. Explain the movements of the sap in plants. 13. Describe the appearance under the microscope of raphides, spiral vessels, and disc-bearing wood -cells . 14. Describe the structure of the bark of an Exogen. 15. Describe freely the anatomy of a leaf. IG. Describe shortly the parts and structures denoted by the following terms, spine, aerial root, phyUodiurrif cambium, stipule, rhizoma. 17. Give examples of phcenogams, cryptogams, exogena and endogens, properly arranged. 18. Describe the principal forms of indeterminate inflorescence. 19. In what natural families do we find siliques, didynamous stamens, labiate corollas, or pappus-bearing achenes. Describe these structures. 20. State the characters of any Canadian Exogenous Order, with examples. 21. Describe the ceU- walls in a living parenchymatous cell. 22. Describe the fibro- vascular tissues in an Exogen- ous stem. 23. Describe the appearance of etomata and glan- dular heirs under the microscope. 24. De^ne proseiichy ma, corm, cyclosis, thallus. 25. Explain the sources of the Carbon and Nitrogen of the plant, and the mode of their assimilation. 26. Describe the pericarp, stating its normal struc- ture, and naming some of its modifications. 27. Explain the natural system in Botany, and state the gradation of groups from the species upward^ with exampleb. J 12 APPENDIX. il^ ONTARIO COLLEGE OF PHARMACY. 1. What do plants feed upon ? 2. What do you understand by the terms Acaulescent, Apetalous, Suffrutescent, Culm ? 8. Name some of the different forms of Primary, Secondary, and Aerial Roots, giving examples. 4. Explain the loUowiug terms descriptive of forms of leaves, giving sketch : — Ovate, Peltate, Crenate, Serrate, Cleft, Entire, Cuspidate, Perfoliate. 5. Explain difference between Determinate and In- determinate inflorescence, giving three examples of each. 6. What organs are deficient in a sterile and a fertile flower ? 7. Give the parts of a perfect flower, with their rela- tive position. 8. Give the difference between simple and compound Pistil, with example of each. 9. Name the principal sorts of buds, and explain how the position of these affects the arrangement of branches. . 10. Give description of multiple and primary roots, with two examples of same ; also explain the difference between these and secondary roots. 11. Name the principal kinds of subterranean stems and branches, and explain how you would distinguish between these and roots. 12. In the classification of plants explain difference between classes and orders : genus and species. 13. Name three principal kinds of simple fruit. 14. When roots stop growing does the absorption of moisture increase or decrease ? Give reason for it. 15. Upon what do plants live ? Indicate how you would prove your answer correct. 16. In what part of the plant, and when, is the work of assimilation carried on ? 17. Name three prmcipal kinds of determinate, and some oiindetermindte inflorescence ; name the esseptiv^' organs of a flo^^^r. APPENDIX. Ud s if ie i- d In I 18. In what res^iectg do plants differ from inorganic mattei* ? And from animals ? 19. Describe a Khizome, Tuber, Bulb; and say if they belong to the root or stem ; which are Rheum, Jalapa, Sweet Potato, Onion ? 20. Define the difference between natural and special forms of leaves ; between simple and compound leaves. Give example of each. Sketch a connate-perfolialo leaf. 21. Mention the parts of an embryo. Of a loaf. Of a pistil. Of a otamen. Of a seed. 22. What is meant by an albuminous seed ? By dioecious flowers ? By a compound ovary ? 23. What is the difference between determinate and indeterminate inflorescence ? How do they influence growth of the stem ? Give three principal kinds of each. 24. Name the parts of a flower. What office is performed by the ovule ? Name two kinds. 25. Name the parts of a vegetable cell. What are spiral ducts ? 26. In what parts of the plant, is the work of absorp- tion carried on ? In what part the work of assimila- tion ? How do plants purify the air for animals ? 27. Explain the natural system of classification in Botany ? Name and characterize the classes of plants. 28. Explain the structure and functions of 1>he Leaf, Bud, Root. 29. Give some of the terms used in describing the ' shape of a simple leaf as concei'ns (a) its general con- tour, (h) its base, {c) its margin, (J) its apex. 30. Name the organs in a perfect flowey ; describe fully the structure of the anther and pollen. What is coalescence and adnation of the parts of a flower ? 81. Explain the terms Raceme, Pappus, Coma, Rhi- zome, Pentastichous. 82. State the distinction between Exogens and Endo- gens. 33. What are cellular structures as distinguished from vascular ? What is chlorophyll ? RF= 144 APPENDIX. t mi 84. Mention the organs of fructification, and explain the process of fertilization in a flowering plant. 85. Explain the structure of a seed, and describe in a few words the process of germination. 86. Djfine what is meant by the following terms : — Morphology, Polycotyledonous, Epiphyte, Peduncle, Stipules. 87. Describe briefly the root stem, leaf, and flower of the common dandelion, giving the functions or ofi&ce of each. 88. Name some of the most common forms of leaves, giving a few rough outlines. 39. Of what part of the flower does the fruit nomin- ally consist ? "What additional Darts are in some inr stances present ? 40. Define the terms Drupe. Pollen, Gynandrous, Pome, Adnate. 41. Explain the process of fertilization in flowering plants, and mention the differe»^ ways in which it is brought about. 49. Enumerate the different varieties of tissue recog- nized by botanists, and give theii? situation in an Endo- genous stem. TB» "«>ND, ,i i