UC-NRLF 
 
 33fl 
 
 DEATH CAMSS 
 Plants Poisonous to Sheep and Battle 
 
 By C.S. Fleming & ff.F. Peterson 
 Univ. of Nevada Bulletin #101 - Feb. 19E1 
 
: ' Kore&try. JMaio L.ibra.r 
 
THE UNIVERSITY QF NEVADA 
 AGRICULTURAL EXPERIMENT STATION 
 
 Bulletin No. 101 
 
 RENO, NEVADA 
 
 February, 1921 
 
 To diminish suffering and loss among domestic animals 
 
 DEATH CAMAS 
 
 (Zygadenus paniculatus and Zygadenus venenosus) 
 
 Plants Poisonous to Sheep and Cattle 
 
 By 
 
 C. E. FLEMING and N. F. PETERSON 
 Of the Department of Range Management 
 
 Assisted by 
 
 M. R. MILLER 
 Of the Department of Chemistry 
 
 and 
 
 DR. L. H. WRIGHT 
 Of the Department of Veterinary Science 
 
 PUBLISHED BY THE UNIVERSITY OF NEVADA 
 RENO, NEVADA 
 
 I 55 
 
 Printed at the 
 
 STATE PRINTING OFFICE JOE FARNSWORTH, SUPERINTENDENT 
 CARSON CITY, NEVADA 
 

 NEVADA AGRICULTURAL EXPERIMENT STATION 
 
 BOAED OF CONTROL 
 
 Hon. G.F.TALBOT (1931) . . . Reno 
 
 Hon.B. F. CUBLEB (1921) Elko 
 
 Hon. WALTEB E. PRATT (1925) Reno 
 
 Hon. Mrs. W. H. HOOD (1927) Reno 
 
 Hon. MILES E.NOBTH (1929) Reno 
 
 OFFICERS 
 
 WALTER E. CLARK, Ph.D President of University 
 
 CABOLYN BECKWITH Secretary 
 
 CHABLES H. GORMAN Comptroller 
 
 STAFF 
 
 SAMUEL B. DOTEN, M.A Director and Entomologist 
 
 F. L. BIXBY, C.E Irrigation 
 
 (In cooperation with Bureau of Public Roads, U. S. D. A.) 
 GEO. HABDMAN, M.S. ....... Assistant in Irrigation 
 
 CHABLES E. FLEMING, B.S.A Range Management 
 
 EDWARD RECORDS,V.M.D. . Veterinarian 
 
 LYMAN R.VAWTEB, D.V.M Pathologist 
 
 MADGE L. FINK, B.A Secretary to Veterinary Department 
 
 M. R. MILLER, B.S Chemist 
 
 MABTHA RYAN Librarian and Secretary to Director 
 
 ^ 
 
STUDIES OF POISONOUS RANGE PLANTS IN THE 
 UNIVERSITY OF NEVADA 
 
 In undertaking the study of poisonous range plants, the Nevada 
 Agricultural Experiment Station has planned a series of experiments 
 to obtain information upon the following points : ( 1 ) the part of the 
 plant which is poisonous, (2) the time of the year when it is dangerous, 
 (3) the kinds of live stock poisoned, (4) the amount which must be 
 eaten in order to cause illness or death, (5) the symptoms shown by 
 the poisoned animals, (6) the conditions under which poisoning occurs, 
 (7) methods of cure and treatment, (8) and methods of preventing 
 poisoning. 
 
 In addition, studies are made of the post-mortem conditions shown 
 by the poisoned animal, and of the chemical nature of the poisonous 
 element found in the plant. 
 
 The basis of all these experiments consists of long series of feeding 
 tests in which plants are brought fresh from the ranges to the Univer- 
 sity and are fed to range animals in pens where they are kept under 
 close observation. 
 
 This bulletin is a report of the results obtained by feeding the plant 
 known as death camas to range sheep and cattle. 
 
 S. B. DOTEN, 
 Director, Nevada Agricultural Experiment Station. 
 
 UNIVERSITY OF NEVADA, 
 
 Reno, Nevada, January, 1921. 
 
 48130, 
 
SECTION I 
 
 DEATH CAMAS 
 
 Zygademis paniculatus and Zygadenus venenosus 
 PLANTS POISONOUS TO SHEEP AND CATTLE 
 
 SUMMARY 
 
 Death camas is a common poisonous plant of the sheep and cattle 
 ranges in Nevada. 
 
 It is a low-growing bright-green plant related to the lilies and the 
 onions. It comes up in the very early spring from a bulb buried eight 
 inches or more in the ground. The bulb is much like an onion, but it 
 has no onion odor, and is covered with a thin black coating. The leaves 
 are long, slender, and grass-like. When the plants come up they look 
 a little like Indian corn ; but the leaf is narrower and more fleshy, and 
 it has a distinct ridge or keel on the under side. At first there appears 
 to be no stem ; but later a flower stalk is sent up bearing a long cluster 
 of pale yellow flowers. 
 
 The first green shoots come up early in the spring before there is 
 grass on the range ; and it is at this season that sheep and some cattle 
 are poisoned. 
 
 It takes from one-fourth to one-half pound of the leaves to make a 
 range sheep sick when the animal is confined in a pen ; it takes a much 
 larger dose, three pounds or more, to kill a sheep under the same condi- 
 tions. On the range where sheep are driven hard and have no chance 
 to rest and recover, smaller doses are probably often fatal. 
 
 On the whole, however, under ordinary range conditions it must be 
 somewhat difficult for even one sheep in a band to obtain a fatal dose of 
 the death camas leaves; and it is probable that many losses thought 
 to have been caused by death camas were in reality caused by some 
 other plant. 
 
 Sheep fatally poisoned by death camas froth at the mouth and 
 slobber freely, and occasionally vomit. They grow weak in the hind- 
 legs and stagger when made to walk. Within a few hours they become 
 very dull and weak, standing with head and ears drooping and the 
 back arched. Later, they go down and thereafter rise with difficulty if 
 at all ; becoming gradually weaker and usually dying within twenty- 
 four hours from the time of feeding. 
 
 Cattle show much the same set of symptoms; but are apt not to 
 froth at the mouth and drool as much as sheep. When in good condi- 
 tion they vomit so freely that they recover within two or three days. 
 
 In our experiments we did not succeed in killing any young cattle 
 with death camas. Doses of three-eighths of a pound to two pounds 
 made the animal sick, but caused prompt and profuse vomiting which 
 brought about a fairly rapid recovery. On the range, death probably 
 occurs only when half -starved cattle eat a considerable quantity under 
 conditions where the system is too weak to throw off the poison or 
 where weak animals, driven hard, are poisoned and get no chance to 
 rest and recpyer. 
 
 There is no known remedy for death camas poisoning; and even if 
 an antidote were discovered, it is not likely that it could be used sue- 
 

 r-r-- 
 
 Figure 1. Toot-Hill Death Camas, the Entire Plant, in Bloom. 
 
cessfully under range conditions. Since poisoning occurs only when 
 weak and hungry animals are turned on to death camas ranges where 
 there is no grass or other green feed, and since ordinarily both sheep 
 and cattle will avoid death camas and eat almost anything else in pref- 
 erence, it is evident that the way to avoid poisoning is to keep half- 
 starved animals off death camas ranges and feed some hay until there is 
 grass ; and then let the animals scatter out and browse at will, choosing 
 their own forage. 
 
 The plants known as death camas have long been recognized as 
 poisonous, being commonly considered as among the most dangerous 
 plants of our western sheep and cattle ranges. Although discussed in 
 nearly all publications dealing with poisonous plants, there is little if 
 any definite information concerning the quantity required to make an 
 animal sick or to cause death; and not much appears to be known 
 about the classes of live stock poisoned, the conditions under which 
 poisoning is most likely to occur, and methods of preventing losses. 
 The experimental feedings and range observations presented in this 
 bulletin were made for the purpose of obtaining exact information 
 upon these points. 
 
 Classes of Live Stock Poisoned. 
 
 All of the range observations seem to show that more sheep than 
 cattle or horses are poisoned by death camas. No losses of horses have 
 been recorded by the Nevada Experiment Station; and it seems that 
 cattle have been poisoned only when hungry and in poor condition in 
 the spring of the year. Many of the losses on the open range which 
 have been attributed to death camas may in reality have been caused 
 by other plants not known at the time to be poisonous. In fact, a large 
 number of range observations made by the Station show that the 
 probability of poisoning by this plant is by no means so great as is 
 commonly supposed. This side of the matter will be discussed at length 
 farther on in this bulletin. 
 
 Common Names. 
 
 Death camas is the name by which these plants are commonly known 
 on the range; but they are also called Mystery Grass, Poison Sego, 
 Poison Onion, Lobelia, and Poison Camas. 
 
 In Nevada the most common kinds are the foot-hill death camas 
 (Zygadenus paniculatus) , and the meadow death camas (Zygadenus 
 venenosus). The former grows in the foot-hills among sagebrush 
 and other range browse ; the latter is more plentiful ,in moist, grassy 
 places. The foot-hill form is more common in Nevada, being found on 
 most of the ranges in the northern part of the State. 
 
 A Description of Death Camas. 
 
 The group of closely-related plants known as death camas were 
 formerly included in the lily family ; but this family has recently been 
 broken up by botanists who have placed the death camas in the 
 "bunch-flower family" (Melanthacece) . 
 
 The plant is erect, producing from two to eight fully formed grass- 
 like leaves. It springs from a layered bulb set from two to eight 
 inches deep in the soil. The bulbs vary in size according to the age of 
 the plant ; but they are commonly from one-half to one and one-fourth 
 inches across and are covered by thin, black, papery coats or layers. 
 The leaves are long, narrow, and curved; varying in length from six 
 
8 
 
 to eighteen inches; they 
 they look a good deal like 
 
 Figure 2. Foot-hill Death 
 Camas, the Young Plant 
 in Early Spring. 
 
 are usually less than one-half inch wide; 
 
 coarse grass blades with a projecting ridge 
 like the keel of a boat on the under side. 
 They are much thicker and more juicy than 
 ordinary grass blades. 
 
 There is at first no well-defined stem, the 
 leaves appearing to rise from near the 
 surface of the ground. The flowers are 
 greenish - yellow or whitish, about one- 
 fourth inch across ; and are produced in a 
 flower cluster from two to ten inches long. 
 The lower flowers bloom first, and may pro- 
 duce seed pods before the upper flowers 
 bloom. The seeds ripen in the summer; 
 but lie dormant until the next spring, when 
 they sprout and grow into tiny leafy 
 plants. These soon develop small bulbs 
 which may not be any larger than a pea 
 by the end of their first summer's growth. 
 It takes a new plant several seasons to form 
 a bulb sufficiently large to begin to produce 
 flowers and seeds. 
 
 The foot-hill death camas differs from 
 the meadow form by having a larger and 
 longer bulb, lying deeper in the soil, usually 
 at a depth of from five to eight inches ; 
 while the bulb of the meadow form is 
 smaller and much shorter and is rarely 
 found more than two inches deep in the 
 ground. The foot-hill death camas is also 
 a much larger plant; its flower cluster is 
 branched at the base, while the much 
 shorter cluster of the meadow form is 
 unbranched. 
 
 Plants Commonly Mistaken for Death Camas. 
 
 Death camas is most commonly confused 
 with the wild onion, although it has no 
 onion odor. When in bloom the two are 
 easily distinguished, for all of the flowers 
 of the onion cluster grow out from the tip 
 of the flower stem, while the flowers of the 
 death camas grow along the sides of the 
 stem as in Figure 4. 
 
 Where the Death Camas Grows. 
 
 Death camas plants may be found on 
 practically every stock range in Nevada, 
 growing more abundantly in the northern 
 half of the State than in the southern. 
 The ground on which the death camas 
 grows is always quite moist in the spring 
 
 of the year; and the typical grazing types in which they are found 
 
are: (1) sagebrush, (2) grass, (3) semimeadow areas, and (4) typical 
 weed ranges where the vegetation consists largely of showy flowering 
 plants. They do not grow in the shade under standing timber. They 
 are found on practically all of the mountain foot-hills, the high open 
 mountain park areas, and in the sagebrush country of northern and 
 western Nevada. 
 
 The Time of Year When Growth Begins. 
 
 The time when death camas starts to grow in the spring varies with 
 the season and also with different exposures and different soils; the 
 green shoots are sometimes found as early as the middle of March. 
 
 Figure 3. Foot-Hill Death Camas. Plants in various stages of growth, 
 from seedlings to mature plant in bloom. 
 
 The plants make their appearance first on sandy soils and on southern 
 exposures. On the dark loamy and clay soils their growth is much 
 retarded; probably because these soils are moist and consequently 
 warm up less readily. If the weather is fairly warm the death camas 
 will begin to grow from ten days to two weeks after the snow melts 
 out in the spring; and the leaves are soon high enough to cause loss. 
 By the latter part of June on the lower ranges, the plant has usually 
 died down. 
 
 How the Flavor of Death Camas Affects the Probability of Poisoning. 
 
 All species of death camas which grow in Nevada have a bitter flavor 
 and are extremely distasteful to cattle and sheep. In all our feeding 
 
10 
 
 tests it was practically impossible to get either sheep or cattle to eat 
 this plant readily, even after going hungry for two or three days. 
 When a hungry animal was first fed, a few mouthfuls would be eaten ; 
 but almost as soon as the plant juices came in contact with the mouth 
 the animal would begin to wrinkle its nose and move its tongue in such 
 a manner as quickly to get rid of what was in its mouth. 
 
 In order to get any large number of plants into an animal it was 
 necessary to resort to forced feedings, which consisted mainly in plac- 
 ing the ground leaves so far back in the animal's mouth that it had 
 to swallow what was given it. When this plant, mixed with palatable 
 
 Figure 4. Foot-Hill Death Camas (on left) and Wild Onion. Notice the differ- 
 ence in the arrangement of the flowers on the stem. The flowers of death 
 camas are scattered along the sides of the stem; those of wild onion form 
 a round cluster at the end of the stem. 
 
 weeds and grasses, was fed to hungry animals they would sort out the 
 grasses and weeds and eat them, avoiding the death camas wherever 
 possible. This shows clearly how sheep and cattle dislike this poisonous 
 plant and try to avoid eating it. 
 
 On many of the grazing ranges in the western part of Nevada, sheep 
 have been closely observed while grazing on ground supporting death 
 camas, with weeds, browse, and a scattering stand of grasses. The 
 sheep nibbled weeds and grasses all around the death camas, leaving it 
 almost untouched. Naturally, no losses occurred under these conditions. 
 
11 
 
 On several of these ranges it was noticed that the death camas plants 
 had been grazed by some animal. A study of conditions on near-by 
 ranges, where it was known that there had been no live stock that 
 season, revealed the fact that a number of rodents, common ground 
 squirrels among others, were eating the leaves and digging up the 
 bulbs. Ordinarily, if there had been sheep on these ranges and poison- 
 ing had occurred, it would have been seen that the death camas plants 
 had been grazed ; and they would have been blamed for the losses. 
 
 A series of similar observations were made on Peavine Mountain, 
 near Reno by J. A. Longyear who states that the tops of death camas 
 plants are nibbled rather freely by ground squirrels. 
 
 Because of the fact that in the experimental work it took a large 
 quantity of death camas to kill a sheep, a series of feeding tests were 
 made with the most palatable young green weeds and grasses to find 
 out the amount of such plants a range sheep will eat before its hunger 
 is satisfied. 
 
 Two yearling lambs in medium condition were fed a mixture of green 
 
 Figure 5. Foot-Hill Death Camas. 
 Plants beginning growth in early 
 spring. 
 
 Figure 6. The Foot- 
 Hill Death Camas. 
 This plant has 
 been nibbled by 
 ground squirrels. 
 
 grasses and weeds. These animals were fed during a series of days all 
 they would eat in the forenoon and afternoon. The average consump- 
 tion of weeds and grass was four and one-half pounds on each half- 
 day, or nine pounds per day. 
 
 Two old ewes weighing 80 and 90 pounds respectively were put to 
 the same test as the lambs ; and it was found that on the average each 
 would eat a little over eight pounds daily. These tests probably show 
 quite accurately the quantity of green feed eaten by a range sheep in a 
 single day. 
 
 With death camas the experimental feeding tests showed that the 
 smallest amount which will make a sheep sick is between one-fourth 
 pound and one pound. Amounts of one-fourth to two and one-half 
 pounds in each feeding made the sheep sick ; but none died from the 
 direct effects of the poisoning. However, two were so weakened that 
 they died later; one from inflammation and ulceration of the fourth 
 
12 
 
 stomach, the other from pneumonia. Quantities of three pounds or 
 more killed the animals in all cases, with the exception of a single sheep 
 which appeared far more resistant to poisoning than the average 
 animal. 
 
 When we compare the capacity of a sheep 's stomach, approximately 
 four and one-half of green grass and weeds at a single feeding, with the 
 quantity of death camas required to kill, approximately three pounds 
 or more ; then it would appear that the sheep would have to graze very 
 largely on death camas in order to secure a fatal dose. 
 
 In order to get a clear idea of how thick a stand of death camas there 
 is on the range early in the spring when the danger is greatest, square- 
 rod plots were laid out where death camas (Zygadenus paniculatus] 
 appeared most abundant on the foot-hills southwest of Reno. On 
 April 12, 1918, 32 plants, all that grew on one square rod, were cut off 
 at a height of three-quarters inch above the ground. The total weight 
 
 Figure 7. Foot-Hill Death Camas. The leaves appear to spring directly 
 from the ground without any stem. 
 
 was 32.8 grams, or a little more than an ounce. On April 15, 52 plants 
 were cut from two square rods and the total weight of leaves cut was 
 28.6 grams per square rod, or approximately one ounce. At this rate 
 it would take sixteen square rods to produce a single pound of the 
 plant. The leaves at this time were from four to eight inches high. 
 
 On all of these plots there was a far heavier stand of death camas 
 than would ordinarily be found on any of the ranges in Nevada. If 
 the plants really grew as thickly on the range as on these selected plots, 
 and if they had reached a height of from four to eight inches, then each 
 acre would produce from 10 to 12 pounds of death camas, enough to 
 poison fatally some three or four sheep. The death camas was cut and 
 weighed at a time of year when all other green vegetation was very 
 scarce, and the likelihood of poisoning was greatest. 
 
 On May 17, 1918, when other range vegetation was quite abundant, 
 
13 
 
 17 death camas plants, all that grew on a square rod, were clipped 
 three-fourths of an inch from the surface of the ground ; they weighed 
 4.8 ounces, somewhat more than one-fourth pound. The plants were 
 then in full bloom, some of them going to seed. At this rate and at this 
 time of year an acre would produce approximately 48 pounds of death 
 camas, enough to poison fatally about 16 head of sheep. However, the 
 plant does not grow as thickly as this uniformly over any sheep range. 
 The square-rod plots were selected areas, chosen because they supported 
 an unusual number of plants. 
 
 Foot-Hill Death Camas (Zygadenus paniculatus) Feeding Experiments with Sheep. 
 
 In the course of the years 1918 and 1919, 69 feedings were made to 
 sheep. Most of these feedings were of leaves, only a few feedings being 
 made of the flower-heads, seed-heads, and bulbs. The results of these 
 feedings are condensed in Table I. 
 
 The results of the experiments presented in this table may be 
 summarized as follows : 
 
 (1) None of the nine feedings of -J pound each had any appreciable 
 effect upon the animal, indicating that this quantity of the plant is 
 practically harmless ; (2) out of the 16 feedings of J pound of the tops, 
 six tests produced no visible symptoms, while 10 made the animals 
 appreciably sick. These feedings show that if sheep in a range flock 
 eat as little death camas as \ pound each, trouble may possibly follow. 
 
 A single feeding of \ pound of the bulbs made one sheep sick, but in 
 a few hours it had completely recovered. It takes several plants to 
 make \ pound of the bulbs, more plants in fact than a sheep could 
 possibly ever pull up ; so the bulbs as. a poisonous part of the plant may 
 be completely disregarded. 
 
 (3) Nine out of 12 feedings of \ pound of the tops produced typical 
 symptoms of poisoning, while three apparently had little effect upon 
 the animals. A half-pound of the tops will generally make a sheep 
 sick ; any larger quantity will almost always cause severe poisoning. 
 
 (4) Four out of five feedings of f pound each made the animals 
 sick. These sheep were much more seriously affected than those fed \ 
 pound each. 
 
 (5) Of seven feedings of one pound each, six caused severe poisoning 
 while one had no effect. Apparently one pound is as much as any 
 sheep can eat without danger of serious poisoning. 
 
 (6) Four feedings of from \\ to 1J pounds all caused severe but not 
 fatal poisoning. 
 
 (7) Five feedings of quantities varying between If pounds and 2 
 pounds caused very severe poisoning, resulting in death in two cases. 
 
 (8) All feedings of three pounds each resulted fatally. However, 
 sheep No. 18 was twice fed 3^ pounds without a fatal result, although 
 the animal was severely poisoned and was sick for more than a day each 
 time. This animal appeared to be very resistant to poisoning by death 
 camas ; later, in tests with other plants, she showed the same resistance 
 to poisoning. 
 
 (9) Three feedings of four pounds of the tops all caused death. It 
 seems fair to assume that under ordinary conditions no sheep can eat 
 such a quantity of death camas and live. Still, four pounds is a far 
 greater quantity than any sheep is likely ever to find on the range. 
 
 (10) Of three feedings of quantities of seed-heads varying between 
 
14 
 
 TABLE I 
 
 FOOT-HILL DEATH CAMAS (Z. paniculatus) . THE FRESH GREEN PLANT 
 
 FED TO SHEEP. 
 
 Animal 
 No. 
 
 w jgj ht Date fed 
 
 Time fed 
 
 Amount 
 fed, Ibs. 
 
 Time symptoms 
 appeared 
 
 Time of death 
 or recovery 
 
 Final result 
 
 13 
 
 69 
 
 72 
 65 
 67 
 64 
 70 
 56 
 81 
 79 
 93 
 90 
 96 
 83 
 71 
 61 
 82 
 93 
 93 
 93 
 93 
 116 
 75 
 72 
 73 
 83 
 77 
 72 
 56 
 56 
 53 
 72 
 120 
 75 
 75 
 69 
 68 
 70 
 66 
 66 
 75 
 64 
 64 
 82 
 94 
 63 
 70 
 80 
 75 
 67 
 68 
 73 
 72 
 70 
 65 
 68 
 75 
 83 
 77 
 94 
 94 
 73 
 83 
 96 
 67 
 65 
 12 
 93 
 88 
 81 
 
 5-22-18 
 5-22-18 
 5-22-18 
 5-22-18 
 6- 4-18 
 6- 4-18 
 6- 4-18 
 5- 6-18 
 5- 6-18 
 5- 9-18 
 5-10-18 
 5-10-18 
 5-14-18 
 5-22-18 
 5-22-18 
 5-22-18 
 5-22-18 
 5-24-18 
 5-25-18 
 6- 4-18 
 6- 4-18 
 4-17-19 
 5- 6-18 
 5- 6-18 
 5- 9-18 
 5-14-18 
 5-15-18 
 5-22-18 
 5-24-18 
 5-25-18 
 5-25-18 
 6- 4-18 
 4-17-19 
 4-23-19 
 5- 5-19 
 5- 7-18 
 5-22-18 
 5-23-18 
 5-24-18 
 4-18-19 
 5-24-18 
 5-25-18 
 5- 9-18 
 5-10-18 
 5-22-18 
 4-22-19 
 4-23-19 
 5- 9-18 
 5-14-18 
 5- 9-18 
 5-10-18 
 5-10-18 
 5-14-18 
 5-24-18 
 5-16-18 
 5-22-18 
 5-15-18 
 5-22-18 
 5-18-18 
 5-24-18 
 5-17-18 
 5-17-18 
 5-22-18 
 5- 6-18 
 6- 4-18 
 6- 4-18 
 5-27-18 
 5-15-19 
 5- 5-19 
 
 2:15 p. m. 
 2:20 p. m. 
 2:25 p. m. 
 2:30 p. m. 
 2:15 p.m. 
 2:25 p. m. 
 2:30 p. m. 
 11:10 a. m. 
 11:30 a.m. 
 10:20 a. m. 
 9:30 a. m. 
 9:40 a. m. 
 11:10 a. m. 
 2:35 p.m. 
 2:40 p. m. 
 2:50 p. m. 
 2:55 p. m. 
 9:10 a. m. 
 10:20 a. m. 
 2:35 p. m. 
 2:40 p. m. 
 11:45 a. m. 
 11:00 a. m. 
 2:40 p. m. 
 11:45 a. m. 
 11:20 a. m. 
 10:40 a. m. 
 3:15 p.m. 
 9:20 a. m. 
 10:30 a. m. 
 10:40 a. m. 
 2:50 p. m. 
 11:45 a. m. 
 11:00 a. m. 
 10:00 a. m. 
 11:30 a. m. 
 3:40 p.m. 
 10:35 a. m. 
 9:25 a. m. 
 9:30 a. m. 
 9:30 a. m. 
 10:40 a. m. 
 11:35 a. m. 
 11:05 a. m. 
 3:50 p.m. 
 10:00 a. m. 
 10:30 a. m. 
 11:50 a. m. 
 10:40 a. m. 
 10:40 a. m. 
 11:35 a. m. 
 10:35 a. m. 
 10:15 a. m. 
 9:40 a. m. 
 10:15 a. m. 
 10:15 a. m. 
 10:00 a. m. 
 11:20 a. m. 
 10:35 a. m. 
 10:25 a. m. 
 10:15 a. m. 
 10:30 a. m. 
 10:40 a. m. 
 2:55 p. m. 
 2:19 p. m. 
 2:20 p. m. 
 10:30 a. m. 
 9:40 a. m. 
 9:50 a. m. 
 
 j 
 
 : 
 : 
 
 1 
 
 1 
 1 
 
 2 
 2 
 2 
 2 
 3 
 3 
 3 
 3 
 4 
 4 
 4 
 
 ; 
 : 
 
 S 
 
 ! 
 
 t 
 
 i 
 
 ' 
 
 
 
 Negative 
 
 8 
 
 
 
 Negative 
 
 6 
 
 
 
 Negative 
 
 24 
 
 
 
 Negative 
 
 28 
 
 
 
 Negative 
 
 27 
 
 
 
 Negative 
 
 26 
 
 
 
 Negative 
 
 25. 
 
 2:55 p.m. 
 3:30 p.m. 
 2:30 p. m. 
 3:30 p. m. 
 
 5:00 p. m. 
 5:00 p. m. 
 5:00 p. m. 
 4:30 p. m. 
 
 Recovery 
 Recovery 
 Recovery 
 Recovery 
 
 Negative 
 
 23--. 
 
 25 
 25 
 
 21 
 9 
 
 
 
 Negative 
 
 7 
 
 17 
 
 7:00 p. m. 
 8:00 p. m. 
 3:55 p. m. 
 3:55 p. m. 
 
 5-2310:00 a. m. 
 5-23 3:00 p. m. 
 5-2310:00 a. m. 
 7:00 p. m. 
 
 Recovery 
 Recovery 
 
 10 
 
 Recovery 
 Recovery 
 
 25 
 
 25 
 
 Negative 
 
 25 
 
 12:00 m. 
 3:50 p. m. 
 
 3:00 p. m. 
 7:45 p. m. 
 
 Recovery 
 Recoverv 
 
 25 
 
 14 
 
 Negative 
 
 26 
 
 
 
 Negative 
 
 8 
 
 
 
 Negative 
 
 20 
 
 
 
 Negative 
 
 9 
 
 6:40 p. m. 
 2:30 p.m. 
 1:00 p.m. 
 4:55 p. m. 
 10:50 a. m. 
 2:40 p. m. 
 1:40 p.m. 
 4:50 p.m. 
 
 5-10 8:00 a. m. 
 5:00 p. m. 
 5:00 p. m. 
 10:00 p. m. 
 11:50 a. m. 
 8:00 p. m. 
 3:00 p.m. 
 7:45 p. m. 
 
 Recovery 
 Recovery 
 Recovery 
 -._ Recovery 
 Recovery 
 Recovery 
 Recovery 
 
 5 
 
 8 
 
 26 
 26 
 
 26 
 
 16 
 
 2... 
 
 Recovery 
 Negative 
 
 29 
 
 26 
 
 
 
 Negative 
 
 46 - 
 
 4:45 p. m. 
 
 7:00 p. m. 
 
 Recovery 
 Negative 
 
 11 
 
 27 
 
 7:00 p.m. 
 1:40 p. m. 
 2:15 p.m. 
 1:30 p. m. 
 2:15 p.m. 
 12:00 m. 
 1:20 p.m. 
 3:30 p. m. 
 7:00 p. m. 
 2:40 p. m. 
 
 5-23 8:00 a. m. 
 8:00 p. m. 
 4:15 p. m. 
 5:00 p. m. 
 4:05 p. m. 
 8:00 p. m. 
 9-11 8:00 a. m. 
 5:00 p. m. 
 5-23 8:00 a. m. 
 4-23 8:00 a. m. 
 
 Recovery 
 Recovery 
 
 27 
 
 27 
 
 Recovery 
 Recovery 
 Recovery 
 Recovery 
 Recovery 
 Recovery 
 Recovery 
 
 29 
 
 28. __ 
 
 28 
 
 10... 
 
 18 
 
 28 
 
 46 
 
 Recovery 
 Negative 
 
 29 
 
 12 
 
 2:30 p. m. 
 3:30 p. m. 
 1:20 p.m. 
 3:15 p.m. 
 2:30 p. m. 
 2:30 p. m. 
 11:05 a. m. 
 2:30 p.m. 
 12:30 p. m. 
 1:00 p. m. 
 12:30 p. m. 
 1:00 p. m. 
 10:00 a. m. 
 11:20 a. m. 
 11:20 a. m. 
 12:20 p. m. 
 11:00 p.m. 
 
 4:30 p. m. 
 5:00 p. m. 
 6:40 p. m. 
 5:15 p. m. 
 5-11 8:00 a.m. 
 5-15 8:00 a. m. 
 2:00 p.m. 
 5-18 8:00 a. m. 
 5-2611:00 a. m. 
 5-18 9:00 a. m. 
 5-23 1:00 a. m. 
 5-19 8:00 a. m. 
 5-25 2:00 p. m. 
 5-18 1:00 p.m. 
 5-18 8:00 a. m. 
 1:25 p. m. 
 5- 7 6:00 p. m. 
 
 Recovery 
 Recovery 
 Recovery 
 Recovery 
 Death 
 
 24 
 
 19 
 
 20 . 
 
 3 
 
 16 
 
 ... Recovery 
 Recovery 
 
 29 
 
 19 
 12 
 22. _. 
 5 
 18 
 18 
 20 
 9 
 21 
 24 
 29 
 8 
 25 
 29 
 26 
 
 Recovery 
 Death 
 
 Death 
 
 Death 
 
 Recovery 
 Recovery- 
 Death 
 
 Death 
 
 Death 
 
 'Recovery 
 t Negative 
 
 
 
 tNegative 
 
 11:30 a. m. 
 
 5-~2~8~ sVob a. m. 
 
 tRecovery 
 tNegative 
 
 4:45 p.m. 7:00 p.m. 
 
 _-. ^Recovery 
 
 *Flower heads fed. tSeed heads fed. JBulbs fed. 
 
15 
 
 J and Vio of a pound, one caused sickness and two were without result. 
 Apparently the green seed-heads are about as poisonous as the leaves 
 and stems. The number of tests, however, was not great enough to 
 prove this conclusively. As a cause of poisoning in range sheep 
 it is believed that the seed-heads of death camas are of very little 
 importance. 
 
 Symptoms of Poisoning in Sheep by Foot-Hill Death Camas. 
 
 Small doses, from J to f of a pound, cause salivation or slobbering in 
 nearly every case. A few cases show nausea and vomiting; there is 
 often a marked increase in the rate of respiration sometimes amounting 
 to panting. The breathing is very irregular; for a time it' is rapid, 
 then very slow. In some cases there is a muscular weakness, which is 
 most noticeable in the hind-legs. 
 
 With larger doses, from one to two pounds, there is in addition to 
 the above symptoms a period of dullness during which the animal 
 stands with the back arched and the head and ears drooping. With 
 still larger doses the animal becomes so weak as to be unable to rise. 
 
 In some cases the mucous membrane of mouth and tongue appeared 
 blue ; and two sheep showed such a spasmodic twitching of the muscles 
 as occurs in strychnine poisoning. 
 
 Time Necessary for Symptoms of Poisoning to Appear. 
 
 The time which elapsed from the time of feeding until symptoms 
 appeared varied from one to seven hours, the average being three hours 
 and ten minutes. The time was slightly less for the larger doses. With 
 doses of less than two pounds the time averaged three hours, twenty-two 
 minutes ; with doses of three pounds or more the average was two hours, 
 twenty-five minutes. 
 
 Length of Time the Poisoned Sheep Were Sick. 
 
 The length of time through which the sheep remained sick was quite 
 variable. After doses of J pound to two pounds the animals were sick 
 for from one to eighteen hours, averaging about five or six hours. As 
 several of these sheep recovered during the night, we do not know 
 exactly how long they were sick. Most of the sheep which died from 
 the direct effects of death camas poisoning were sick from twenty to 
 twenty-five hours; and one was down and unable to rise for nearly 
 three days before it died. 
 
 Some Typical Cases of Death Camas Poisoning in Sheep. 
 
 Case 1. A yearling wether weighing 81 pounds was fed J pound of 
 the leaves of death camas at 11 : 10 a. m. May 5, 1918. At 2 : 55 p. m. it 
 began to froth at the mouth and made attempts to vomit. The breath- 
 ing was very irregular, alternately rapid and slow. At 4 : 30 p. m. the 
 animal seemed to be getting better and by 5 p. m. it appeared to have 
 recovered completely. 
 
 Case 2. About one month later, on June 4, 1918, the same sheep, now 
 weighing 93 pounds, was fed J pound at 2 : 35 p. m. At 3 : 50 p. m. it 
 began slobbering; and at 4:05 p. m. it was nauseated and began to 
 vomit. The breathing was at first fast' and shallow, then slow and full,, 
 with occasional slight pauses. By 4 : 30 it had vomited an amount esti- 
 mated at f of a quart. Vomiting ceased soon afterward and by 4 : 50 
 the sheep was much better. When next observed, at 7 :45 p. m., it was 
 eating hay and appeared to have fully recovered. 
 
16 
 
 Case 3. A yearling wether weighing 56 pounds was fed pound of 
 death camas leaves at 3 : 15 p. m. May 22, 1918. At 4 : 35 it was froth- 
 ing at the mouth and trying to 
 vomit. At 4 : 40 it was vomiting 
 freely. At 7 p. m. it was still 
 frothing at' the mouth, but had 
 ceased vomiting and was getting 
 better. At 8 p. m. it seemed to 
 have recovered. At 10 p. m. it was 
 again slobbering a little. Next 
 morning at 8 o'clock it had fully 
 recovered. 
 
 Case 4. A yearling wether fed f 
 pound of the leaves at 9 : 25 a. m. 
 May 24, 1918, began slobbering a 
 little at 2 : 15 p. m. This gradu- 
 ally increased, and at 3 : 20 it was 
 foaming freely at the mouth. At 
 4 p. m. it was still slobbering a 
 little ; but at 4 : 15 it began eating 
 grass and seemed to have recovered 
 fully. No other sj^mptoms were 
 noted. 
 
 Case 5. A ewe weighing 75 
 pounds was fed 1J pounds of death 
 camas at 11:50 a. m. At 2:30 
 this sheep was grinding its teeth 
 and slobbering freely. At 3 : 40 it 
 was dull and stood with the head 
 and ears drooping, still frothing 
 freely at the mouth. At 4 : 30 the 
 animal appeared to have nearly 
 recovered, and was nibbling at 
 feed. 
 
 Case 6. A ewe weighing 68 
 pounds was fed 1J pounds of death 
 camas at 10: 40 a. m. May 9, 1918. 
 It began to froth at the mouth at 
 1:20 p. m. At about 1:30 it 
 vomited a considerable amount. At 
 2 : 30 it was slobbering freely, and 
 Figure 8. Death Camas Poisoning. stood with drooping head ; showing 
 
 a decided weakness in the hind legs. At 3 : 30 it was salivating less 
 freely, but still stood with head drooping. At 4 : 30 it was getting 
 better ; but was still slobbering a little, and refused to eat. At 6 : 40 it 
 appeared to have fully recovered. 
 
 Case 7. A ewe weighing 83 pounds was fed three pounds of death 
 camas leaves on May 15, 1918, at 10 a. m. At 1 : 30 p. m. it was slob- 
 bering freely, was weak, and staggered when made to move. The 
 breathing was labored, and at times the animal vomited. These symp- 
 toms continued, the animal growing worse until 3 p. m. and becoming 
 weak enough by 4 p. m. to stagger when walking ; it was then so weak 
 
17 
 
 that it could easily be pushed over. The mucous membranes of the 
 mouth and tongue were bluish. At 7 : 30 p. m. it seemed better, and did 
 not appear so weak. At 9 a. m. next day it was down flat on the side 
 and unable to rise. At 11 a. m. it had twitching movements of the 
 muscles similar to those in strychnine poisoning. The animal remained 
 down all that day. Next morning it was still down and appeared to be 
 getting weaker; the breathing was labored and was accompanied by 
 peculiar grunts. At 9 a. m. on the 18th it was found dead, but still 
 warm. 
 
 Case 8. A ewe weighing 77 pounds was fed three pounds of death 
 camas at 11 : 20 a. m. May 22, 1918. At 12 : 30 it was frothing at the 
 mouth ; by 1 : 30 it was frothing freely at the mouth and vomiting ; 
 these symptoms continued until about 2 : 30. By 2 : 50 the animal was 
 weak in the hind legs and staggered when made to walk. The animal 
 continued to get worse, and by 4 p. m. was very weak and dull, standing 
 with head and ears drooping and the back arched. At 4 :30 it vomited 
 again. At 7 a. m. the animal was very dull, and staggered when made 
 to move. It continued to grow worse until 10 p. m. Next' morning, 
 at 8 a. m. it was very weak and unable to get up. It remained in this 
 condition all the forenoon ; and died quietly at 1 : 30 p. m. 
 
 Meadow Death Camas (Zygadenus venenosus) Feeding Experiments with Sheep. 
 Only three feeding tests were made, as the plant is not at all abun- 
 dant on the ranges in western Nevada ; and material for the tests was 
 necessarily limited. It is much less important on Nevada ranges than 
 the foot-hill death camas. The results of the three feedings are sum- 
 marized in Table II. 
 
 TABLE II 
 
 MEADOW DEATH CAMAS (Z. venenosus}. THE GREEN LEAVES AND FLOWERS 
 
 FED TO SHEEP. 
 
 Animal 
 No. 
 
 Weight 
 Ibs. 
 
 Date fed 
 
 Time fed 
 
 Amount 
 fed, Ibs. 
 
 Time symptoms 
 appeared 
 
 Time of death 
 or recovery 
 
 Final result 
 
 37 
 
 90 
 
 6- 9-19 
 
 9:45 a. m. 
 
 \ 
 
 
 
 Negative 
 
 37 
 62 
 
 93 
 
 101 
 
 6-11-19 
 6-26-19 
 
 10:50 a. m. 
 11:00 a. m. 
 
 1 
 2 
 
 1:40 p. m. 
 11:50 a. m. 
 
 5:00 p. m. 
 After 11:00 p. m. 
 
 Recovery 
 Death 
 
 
 
 
 
 
 
 
 
 The experiments summarized in Table II show that this plant is 
 poisonous and that amounts of one pound or more will cause serious 
 poisoning in sheep. The symptoms produced by this plant are almost 
 identical with those described for the foot-hill species, as will be seen 
 from the following typical cases : 
 
 Typical Cases of Poisoning in Sheep, Meadow Death Camas. 
 
 Case 1. A ewe weighing 93 pounds was fed one pound at 10 : 50 a. m. 
 At 1 : 40 p. m. it was foaming at the mouth. At 2 : 40 it was chewing 
 cud, but still foaming at the mouth. At 5 p. m. it appeared to have 
 recovered. 
 
 Case 2. On June 26, 1919, a ewe weighing 101 pounds was fed two 
 pounds of the plant at 11 a. m. At 11 : 50 it was foaming at the mouth 
 and vomiting. At 1 p. m. the respiration was rapid and irregular, 
 varying from 55 to 70 per minute. It still frothed freely at the mouth, 
 the froth being scattered all over the pen. By 4 : 15 it was very weak, 
 staggered when walking, trying to vomit. The animal then appeared 
 
18 
 
 
 
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 i 
 
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 I* 
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 j 
 
 
 
 
 
 
 
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 CQ 
 
 
 : | 
 
 
 
 
 
 1 
 
 
 If 
 
 
 i 
 
 
 
 
 ! ! 
 
 i 
 
 
 W 
 
 V^ 
 
 
 
 
 
 
 ; 
 
 
 00 
 
 -N.^ , 
 
 i i 
 
 
 
 
 ; ; 
 
 ; 
 
 
 ll 
 
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 : 
 
 
 
 ^coco. 
 
 coca^ 
 
 
 
 
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 ^ 
 
 
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 1 - I ^" H 
 
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 N.H 
 
 ^ 
 
 
 T- 
 
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 N 
 
 
 <N<**I 
 
 <M^ 
 
 
 
 
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 r-l # 
 
 
 ^ 
 
 
 
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 -jjcoco 
 
 CC^ 
 
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 ^- l - 
 
 
 
 
 2<N<M 
 
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 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 " M1 * 10 
 
 LO.H.H 
 
 
 
 
 
 
 
 
 HC.C005 
 
 M i 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 HierH 
 
 
 
 
 
 
 
 
 
 
 ! j 
 
 
 
 
 
 
 
 
 
 g 
 
 
 
 
 
 
 Species of plant 
 
 Part of plant fed 
 
 Dose 
 
 Number fed 
 
 Number made sick 
 Number of deaths 
 
 N umber showing slobber 
 Retching and regurgitat 
 Respiration rapid, irregi 
 Weak and dull... 
 
 1 
 
 c 
 ^ 
 
 s 
 
 15 
 ^ 
 
 2 
 ^ 
 
 1 
 
 a 
 
 1 
 
 
 
 +- 
 
 "o 
 
 3 
 
 S 
 
 111) 
 
 Mouth and tongue blue . 
 Twitching of muscles.. 
 
19 
 
 to be strangling, perhaps due to froth getting into the windpipe. It 
 fell at 4 : 30 and could not get up again ; at 4 : 45 it got up, but could 
 barely walk. At 7 p. m. it was down and could not be induced to rise. 
 It continued to get weaker and duller until 10 : 30 p. m., when the 
 observer left for the night. The animal probably died soon afterward ; 
 as it was dead, cold and stiff, at 8 the following morning. 
 
 A Table of Symptoms of Death Camas Poisoning in Sheep. 
 
 Table III gives in very condensed and concrete form the effects of 
 various quantities of death camas (Z. paniculatus and Z. venenosus) 
 when fed to sheep (see page 18). 
 
 Feeding the Green Foot-Hill Death Camas to a Ewe with Suckling Lamb. 
 
 Reports from various sources made it seem possible that suckling 
 lambs might be poisoned by alkaloids secreted in the mother's milk 
 when the ewes fed upon this plant, and before the lambs were old 
 enough to nibble at it. To test this matter, a ewe with a suckling lamb 
 was fed the foot-hill death camas under the conditions listed in 
 Table IV. 
 
 TABLE IV 
 
 FOOT-HILL DEATH CAMAS (Z. paniculatus). THE FRESH LEAVES FED TO A EWE 
 
 WITH SUCKLING LAMB. 
 
 Animal 
 No. 
 
 Date 
 
 Time fed 
 
 Amt. 
 fed, 
 Ibs. 
 
 
 Weight 
 Ibs. 
 
 Time 
 symptoms 
 appeared 
 
 Time of 
 recovery 
 
 Effect on 
 ewe 
 
 Effect on 
 lamb 
 
 37 
 
 4- 1-19 
 
 1*30 p. m. 
 
 j 
 
 
 98 
 
 
 
 Negative 
 
 Negative 
 
 
 4- 2-19 
 
 3:30 p. m. 
 
 
 
 
 
 
 N egative 
 
 Negative 
 
 
 4- 3-19 
 
 1 '30 p. m. 
 
 
 
 
 
 
 Negative 
 
 Negative 
 
 
 4- 4-19 
 
 1:30 p.m. 
 
 
 
 
 
 
 Negative 
 
 Negative 
 
 
 4- 9-19 
 
 9:00 a. m. 
 
 
 
 
 
 
 Negative 
 
 Negative 
 
 
 4-10-19 
 
 8:40 a. m. 
 
 
 
 
 
 
 Negative 
 
 Negative 
 
 
 4-11-19 
 
 9:00 a. m. 
 
 
 
 
 
 
 Negative 
 
 Negative 
 
 
 4-16-19 
 
 8:40 a. m. 
 
 
 
 
 
 
 Negative 
 
 .Negative 
 
 
 4-17-19 
 
 8:30 a. m. 
 
 
 
 
 11:30 a. m. 
 
 4:00 p. m. 
 
 Recovery 
 
 Negative 
 
 
 4-18-19 
 
 9-30 a. m. 
 
 1 
 
 
 
 10-00 a m. 
 
 11-00 a m 
 
 
 Negative 
 
 
 4-19-19 
 
 9:00 a. m. 
 
 j 
 
 i 
 
 
 7:30 p. m. 
 
 4-208:00 a. m. 
 
 Recovery 
 
 Negative 
 
 
 4-22-19 
 
 10:00 a. m. 
 
 i 
 
 . 
 
 
 1:00 p. m. 
 
 2"00p m 
 
 Recovery 
 
 Negative 
 
 
 
 
 
 
 
 
 
 
 
 The tests recorded in Table IV show that although the ewe was fed 
 amounts varying from -J pound to 1 pounds and was made sick four 
 times, still the suckling lamb was not affected during any of the twelve 
 feedings of its mother. 
 
 In the case of the ewe these feedings would also seem to indicate that 
 there is little or no tendency for a sheep to become immune to the 
 poisonous effects of death camas after feeding repeatedly upon it. 
 
 Feeding Green Foot-Hill Death Camas to Cattle. 
 
 Table V summarizes the results of eighteen tests in which the fresh 
 green plants were fed to cattle (see next page). 
 
 It appears from this table that cattle are quite susceptible to the 
 poisonous principle of the foot-hill death camas. Out of the eighteen 
 feedings, ten made the animal sick; but no deaths occurred. It was 
 almost impossible to get cattle to eat more than two pounds of the 
 plant; because they soon became so violently sick that they vomited 
 up all the material eaten. Two small feedings of pound each had no 
 apparent effect upon the animals fed; but quantities of from f of a 
 pound to two pounds usually caused symptoms of poisoning. In some 
 instances poisoning was quite severe, reducing for several days the 
 vigor and strength of the animal. 
 
20 
 
 TABLE V 
 FOOT-HILL DEATH CAM AS (Z. paniculatus) . THE GREEN LEAVES FED TO CATTLE. 
 
 AnimaJ 
 No. 
 
 Weight 
 Ibs. 
 
 Date fed 
 
 Time fed 
 
 Amount 
 fed, Ibs. 
 
 Time symptoms 
 appeared 
 
 Time of death 
 or recovery 
 
 Final result 
 
 
 137 
 
 4- 8-19 
 
 8:00 a. m. 
 
 i 
 
 
 
 Negative 
 
 
 203 
 
 4-12-19 
 
 8:45 a. m. 
 
 
 
 
 
 
 
 137 
 
 4-10-19 
 
 8:30 a. m. 
 
 I 
 
 
 
 Negative 
 
 
 165 
 
 -10-19 
 
 9-00 a m 
 
 I 
 
 11-30 a m 
 
 
 
 
 165 
 
 -15-19 
 
 9:00 a. m. 
 
 | 
 
 11-00 a m 
 
 
 
 
 165 
 
 - 8-19 
 
 8-30 a. m. 
 
 
 9'30 a m 
 
 4'30 p m 
 
 Kecovery 
 
 
 203 
 
 -10-19 
 
 9:45 a. m. 
 
 
 
 
 
 
 137 
 
 -12-19 
 
 8:30 a. m. 
 
 
 
 
 Negative 
 
 
 143 
 
 -16-19 
 
 9:00 a. m. 
 
 
 
 
 
 
 150 
 
 4-25-19 
 
 10:50 a. m. 
 
 
 About 12-00 m 
 
 4-26 8'00 a m 
 
 egative 
 
 
 208 
 
 4-10-19 
 
 10:20 a. m. 
 
 
 
 
 
 
 208 
 
 4-16-19 
 
 10:20 a. m. 
 
 
 10-50 a m 
 
 
 
 
 208 
 
 4- 8-19 
 
 9-00 a m 
 
 1 
 
 
 
 tvecovery 
 
 
 208 
 
 4-12-19 
 
 10-00 a m 
 
 1 
 
 11 -30 a m 
 
 4 13 4 '00 p m 
 
 
 
 193 
 
 4-16-19 
 
 11-30 a m 
 
 1 
 
 
 
 
 8-- 
 
 220 
 
 4-14-19 
 
 10:20 a. m. 
 
 1* 
 
 
 
 recovery 
 
 5 
 
 208 
 
 4-19-19 
 
 10-00 a m 
 
 if 
 
 10-20 a m 
 
 4-22 8-00 a m 
 
 - gative 
 
 6 
 
 193 
 
 4-25-19 
 
 9'30 a m 
 
 2 
 
 lO'OO a m 
 
 4~28 8 -00 a m 
 
 recovery 
 
 
 
 
 
 
 
 
 
 Symptoms Exhibited by Poisoned Cattle. 
 
 Slobbering was not so common a symptom in cattle as in sheep, while 
 vomiting was much more common and more profuse. This vomiting 
 made the animals appear very thin until they recovered sufficiently to 
 eat. A rise in the rate of respiration was a common symptom. 
 Severely poisoned cattle became very weak and dull; the gait was 
 unsteady, particularly in the hind-legs, the animals sometimes stum- 
 bling with the hind feet. A few were either so weak that they were 
 unable to get up, or else they would fall over when walking. Grinding 
 of the teeth and diarrhea were each observed in a single animal. 
 
 Length of Time Required for Symptoms to Appear in Cattle. 
 
 The time from the middle of the feeding period until cattle became 
 sick varied from 20 minutes to 2^ hours, averaging about 1 hour and 
 7 minutes. They remained sick for from 3 to 22 hours, averaging 
 hours. 
 
 Some Typical Cases of Death Camas Poisoning in Cattle. 
 
 Case 1. A calf weighing 165 pounds was fed f of a pound of death 
 camas leaves at 9 a. m., April 10, 1919. At li : 30 it was sick and 
 vomited freely. It remained sick, vomiting frequently, until 1 : 30. At 
 3 p. m. it appeared to have recovered. 
 
 Case 2. A calf weighing 150 pounds was fed J pound of the leaves 
 at 10 : 50 a. m., April 23, 1919. It vomited between noon and 1 p. m. 
 At 3 p. m. it was lying down and appeared dull. When made to get up 
 it walked with an unsteady gait. At 5 p. m. it was up and eating hay. 
 At 8 a. m. next day it was still slobbering; but by 5 p. m. it had 
 apparently recovered. 
 
 Case 3. A calf weighing 208 pounds was fed one pound of death 
 camas at 9 a. m., April 8, 1919. At 10 a. m. it began vomiting and 
 frothing slightly at the mouth. At 11 : 20 it was breathing at the rate 
 of 94 times per minute. At 2 : 45 it had stopped vomiting and the 
 respiration had fallen to 34 per minute. The animal was still slightly 
 sick at 3 : 30 p. m. but was eating, and appeared to have nearly 
 
21 
 
 recovered at 4 : 30 p. m. At 8 : 30 next morning it was walking with 
 a peculiar gait, frequently stumbling with the hind feet. 
 
 Case 4. A calf weighing 208 pounds was fed 1J pounds at 10 a. m., 
 April 19, 1919. At 10 : 20 a. m. it began vomiting, and vomited again 
 at 11 : 20 a. m. Was grinding the teeth almost constantly from 10 : 30 
 until noon. At noon the respiration was 40 per minute. This calf was 
 able to get up at 2 p. m., but walked with a very unsteady gait, espe- 
 cially noticeable in the hind legs. This condition continued until 9 : 30 
 p. m. At 8 o'clock next morning it was still weak and looked very thin. 
 
 Figure 9. Death Camas Poisoning. 
 This calf shows slobbering after 
 eating death camas. This symptom 
 is more common in sheep than in 
 cattle. 
 
 Figure 10. Death Camas Poisoning. 
 This calf shows a common symp- 
 tom weakness in the hind-legs. 
 
 It ate a little hay, but soon quit ; the bowels were quite loose. At 
 8 a. m. on April 22, it appeared to have recovered ; but was still thin 
 and a little dull. 
 
 Case 5. A calf weighing 193 pounds was fed two pounds of death 
 camas leaves at 9 : 30 a. m. At 10 a. m. it began to slobber, the respira- 
 tion then being 56 per minute. It vomited between noon and 1 p. m. 
 At 3 p. m. it was still dull, and walked with an unsteady gait when 
 made to get up. Next morning it appeared to have fully recovered. 
 
 Meadow Death Camas, Feeding Tests with Cattle. 
 
 Owing to the scarcity of material, few tests were made with this 
 species. The five feedings made are summarized in Table VI. 
 
 TABLE VI 
 MEADOW DEATH CAMAS (Z. vcnenosus). THE GREEN LEAVES FED TO CATTLE. 
 
 Animal 
 No. 
 
 Weight 
 Ibs. 
 
 Date fed 
 
 Time fed 
 
 Amount 
 fed. Ibs. 
 
 Time symptoms 
 appeared 
 
 Time of death 
 or recovery 
 
 Final result 
 
 8 
 
 220 
 
 6-11-19 
 
 2:00 p. m. 
 
 
 
 
 Negative 
 
 9 
 
 235 
 
 6-11-19 
 
 2*30 p. m. 
 
 i 
 
 
 
 Negative 
 
 1 
 
 10 
 
 138 
 330 
 
 6-11-19 
 6-11-19 
 
 11:45 a. m. 
 2'40 p m 
 
 1 
 
 12:45 p. m. 
 
 2:40 p.m. 
 
 Recovery 
 Negative 
 
 8 
 
 220 
 
 6-12-19 
 
 8:45 a. m. 
 
 i* 
 
 1:00 p.m. 
 
 6-138:00 a. m. 
 
 Recovery 
 
22 
 
 Summary of Results of Feeding Death Camas to Cattle. 
 
 Table VII shows graphically the effect of various amounts of death 
 camas when fed to cattle in experimental tests. 
 
 TABLE VII 
 
 DEATH CAMAS (Z. paniculatus and Z. venenosus). SUMMARY OF SYMPTOMS, 
 FEEDING EXPERIMENTS WITH CATTLE. 
 
 Species fed 
 
 Zygadenus paniculatus 
 
 Zy gadenus venenosus 
 
 Dose 
 
 2 
 
 3 
 2 
 
 1 
 2 
 
 5 
 
 2 
 
 1 
 2 
 9 
 
 2 
 
 1 
 
 1 
 3 
 3 
 
 1 
 
 11 
 1 
 
 u 
 
 1 
 1 
 
 2 
 
 1 
 1 
 
 1 
 
 1 
 
 I 
 
 1 
 
 1 
 
 1 
 1 
 
 H 
 
 i 
 
 Number fed 
 
 Number made sick 
 
 Number showing: 
 Slobbering 
 
 
 
 
 
 
 Regurgitating 
 
 
 
 2 
 
 .... 
 
 1 
 
 1 
 1 
 
 1 
 
 1 
 
 
 
 1 
 
 
 1 
 
 Dull 
 
 
 
 
 
 
 
 Unsteady gait 
 
 
 
 ? 
 
 
 2 
 
 
 
 
 
 
 i 
 
 Reluctant to rise 
 
 
 
 ? 
 
 
 
 
 
 
 
 
 Respiration rapid 
 
 
 
 
 1 
 
 1 
 1 
 
 
 
 
 
 
 
 
 
 Stumbling on hind legs 
 
 
 
 
 
 
 
 
 
 
 
 Unsteady on hind legs 
 
 
 
 
 
 ? 
 
 
 
 
 
 
 
 
 Fall, and hardly able to get up 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 Grinding teeth 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 i 
 
 i 
 
 Weak . . . 
 
 
 
 
 
 1 
 
 
 1 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Conditions Under Which Death Camas Poisoning Is Most Likely to Occur. 
 
 As has been stated, death camas contains a bitter substance extremely 
 distasteful to both sheep and cattle. Consequently the plant is eaten by 
 these animals only under stress of extreme hunger or prolonged 
 starvation. 
 
 Most of the cases of death camas poisoning have occurred early in 
 the spring. This is a time of year when all palatable vegetation is 
 scarce, and range animals are often poor and hungry, depending of 
 course upon the way in which they have been handled during the 
 winter. Under these conditions, on a range supporting very little 
 palatable vegetation, hungry animals will eat almost any plant in order 
 to satisfy their hunger. This is well illustrated by a loss of cattle which 
 took place in Elko County. 
 
 A herd of cattle were being trailed through sagebrush country where 
 the grass and weeds were just beginning to grow, but where a consid- 
 erable number of death camas plants had already made their appear- 
 ance. The cattle were thin and hungry, and at every opportunity they 
 bit off the death camas plants. A rather large number of cattle died 
 as a result of this drive. Some of the poisoned animals that were left 
 behind recovered ; those that were driven hard in most cases died on the 
 trail. 
 
 In regard to cattle, then, it may be said that the following are the 
 range conditions under which death camas poisoning is most likely to 
 occur: (1) When hungry stock are unloaded from the cars in spring 
 and turned out on a depleted range where death camas is common, and 
 there is very little grass; (2) When cattle are trailed from one range 
 to another in the spring when all palatable feed is scarce; (3) When 
 hungry animals in poor condition are turned out to rustle for them- 
 selves in the early spring before the grass is up, so that they are forced 
 to graze any and all plants in order to satisfy their hunger. 
 
 When sheep are grazing openly and quietly on a range, they show 
 great care in the selection of the forage they eat. However, when they 
 are being trailed from one place to another, they have no chance to 
 
23 
 
 choose what they will eat, with the result that they eat anything that is 
 not absolutely repellant. If death camas is common, and it usually is, 
 they eat so much of it that they get more of the poison than they can 
 throw off. They are constantly forced to move along on the trail by 
 dogs and herders, and death naturally follows. 
 
 Figure 11. Thin and Hungry Cattle on Poor Pasture. Early in the 
 spring animals in this condition are ravenous for green feed. They 
 will then eat death camas or other poisonous plants which ordinarily 
 they would not touch. 
 
 Figure 12. Cattle on Good Mountain Pasture. Well-fed animals on good 
 range will ordinarily avoid poisonous plants almost wholly. 
 
 It should always be remembered that when a sheep is hungry it 
 usually eats greedily the plant on which it is feeding, or else rushes 
 to another plant for fear some other sheep will get there before it does. 
 But when sheep are grazing openly and quietly, they nip off only the 
 tender and juicy parts of the plant, the leaves and young stems, and 
 carefully select the plants on which they feed. 
 
24 
 
 How to Avoid Death Camas Poisoning in Sheep and Cattle. 
 
 Evidently in order to avoid losses on a range where death camas is 
 common, sheep should be so handled that they are never bunched up nor 
 extremely hungry. If they are to be driven from one range to another, 
 it is best to allow them to graze for an hour or two in the morning just 
 as openly and quietly as possible before starting to move them. This 
 will allow all the animals to fill with good forage and they will then use 
 greater care in the selection of their food for the remainder of the day. 
 This would not be the case if they were started on the trail immediately 
 after leaving the bed-ground. 
 
 Figure 13. Sheep Grazing at Will on Sagebrush Range. When allowed 
 to feed quietly in scattered formation, sheep will ordinarily wholly 
 avoid death camas and many other poisonous plants. 
 
 Another very important point is to get the sheep off the bed-ground 
 just as early in the morning as possible. When a sheep beds down at 
 night it is usually full and contented. By morning it is beginning to 
 get rather empty, and the longer it is kept' on the bed-ground the 
 hungrier it becomes ; it is then far more apt to be poisoned when it gets 
 out on the range where the death camas is common. 
 
 In most of the cases of death camas poisoning thus far observed, the 
 animals were poisoned during the forenoon. This is due to the fact the 
 attractiveness of the plant decreases as the stomach becomes full. Thus 
 plants which may seem to be highly palatable and to be relished during 
 the morning hours are often not touched at all later in the day. This 
 is quite true of the death camas. It is grazed chiefly during the early 
 morning hours, and is seldom touched by an animal whose stomach 
 is nearly full. Therefore it is highly important that the sheep should 
 be so handled during the early morning hours that they will have the 
 greatest freedom in the selection of their range forage; if possible, 
 during this part of the morning they should be grazed on range free 
 from death camas, or where it has only a very scattering growth. 
 
25 
 
 In Nevada the prevailing method of handling sheep, especially in the 
 spring of the year, is to establish a main camp from which the sheep 
 are grazed daily until all the feed in the immediate vicinity of the 
 camp has been eaten out to a distance of two or three miles in every 
 direction. This requires long daily drives back and forth in order to 
 get away from range that has already been grazed. Thus the sheep trail 
 over the same ground each day, until all the forage on the range around 
 the bed-ground has been completely eaten off. 
 
 This method of handling can only result in all the plants being eaten, 
 whether poisonous or not ; for the most attractive ones are first grazed, 
 and when these are gone the less palatable ones are left to be eaten, 
 including, of course, the death camas. 
 
 In order to avoid the losses which result from such improper methods 
 of handling sheep, they should be allowed to bed down wherever they 
 happen to be when night comes. They will then always be on fresh 
 feed in the morning. The variety of forage from which to choose will 
 be much greater; and the probability of poisoning will be far less; 
 providing, of course, that the animals are gotten off the bed-ground 
 early in the morning and are allowed to spread out and graze openly 
 and quietly, each ewe with her lamb. Close-bunched grazing, running, 
 trailing, and massing should be avoided ; not only to reduce losses from 
 poisonous plants, but also for the good of the ewe and her lamb, and 
 for the most full and effective use of the range forage. 
 
 Remedies for Death Camas Poisoning. 
 
 For animals poisoned by death camas there is known at present no 
 practical remedy. The best treatment is to let the poisoned animals 
 entirely alone, disturbing them only when it is absolutely necessary. 
 After an animal has been poisoned it is very much weakened and 
 should be given all the care that is practicable on the range. If it can 
 be kept on good feed and driven just as little as possible for the first 
 two or three days, it will often recover rapidly. 
 
SECTION II 
 
 The material included in this section is of greater interest to chemists 
 and veterinarians than to livestock owners. 
 
29 
 
 POST-MOETEM CONDITIONS 
 
 Autopsies upon six sheep whose death was caused by death camas in 
 feeding experiments showed the following post-mortem conditions : 
 
 There appeared to be no outstanding lesions which would serve to 
 indicate a characteristic effect due to poisoning by this plant. On the 
 whole, the lesions shown were those of a general toxemia. The condi- 
 tions were such as are found more or less uniformly, with individual 
 variations, after death caused by the ingestion of various toxic or semi- 
 toxic plants. 
 
 Various degrees of congestion in the gastro-intestinal tract and in 
 its lymphatic system appeared to be prominent symptoms. In some 
 instances the same condition was also found in the kidney, spleen, and 
 liver. The lungs appeared to show no change. In some cases the heart 
 displayed small hemorrhages beneath the epicardium and endocardium, 
 characteristic of toxemia. Considerable quantities of free fluid were 
 observed in the thoracic and abdominal cavities. 
 
 THE ACTIVE PRINCIPLE OF DEATH CAMAS 
 
 It has long been known that alkaloids are partially, if not wholty, 
 responsible for the poisonous properties of the death camas. Different 
 investigators have studied various species of Zygadenus, and the lack 
 of uniformity in the results obtained is not surprising. In the bulk of 
 the work reported it is stated that alkaloids have either been isolated 
 or detected; a single worker found resins in the plant which had 
 poisonous properties. Later attempts to verify these findings in closely 
 related species resulted in failure. 
 
 Two physiologically active resins were, found by Vejux-Tyrode in 
 1904 in the bulbs of Zygadenus venenosus from Montana. From one of 
 the resins he isolated a basic body which he designated zygadinein and 
 an acid zygadenic acid. In animal experiments he found the zyga- 
 dinein to be the active principle. When given in minute doses to 
 guinea pigs, rabbits, and dogs it produced salivation, staggering and 
 respiratory paralysis followed by death, in some cases in a few minutes 
 but usually within a few hours. In 1913 the chemists of the Wyoming 
 Station, F. W. Heyl and F. E. Hepner, investigated Zygadenus inter- 
 medius for similar toxic resins, but were unable to isolate any toxic 
 substance from the resin or even to establish the toxicity of the resin 
 itself. 
 
 The work of early investigators consisted of color tests made upon 
 impure products and led to conclusions that the alkaloids in the species 
 tested belonged to the veratrine group. 
 
 In 1903 George Heyl obtained an alkaloid from a California species 
 of Zygadenus. The alkaloid found amounted to 0.4%. It was soluble 
 in ether and nearly insoluble in water. Its melting point was 134135. 
 It formed a crystalline hydrochlorid. 
 
 Alkalodial analyses of Zygadenus intermedius were made in Wyo- 
 ming in an endeavor to determine the quantity of alkaloidal material 
 present in the different parts of the plant. On account of the lack of 
 suitable methods for the determination, the results are probably not so 
 
30 
 
 accurate as might be desired and show only a fair degree of uniformity. 
 Figures for the amounts found in the dried leaf varied from 0.57% 
 to 0.66%; bulb, 0.188% to 0.57%; flower, 1.07% to 1.35%; root, 
 0.306% to 0.32%. 
 
 A quantity of material was prepared and submitted to Dr. Phillip 
 Mitchell and Mr. Geo. Smith for toxicological experiments. The mate- 
 rial used in these experiments was not the more highly purified crystal- 
 lized alkaloid which was reported on later. It was found that when 
 injected intraperitoneally a quantity between 4.6 mg. and 5.1 mg. would 
 produce death in a guinea pig. When administered by mouth a com- 
 paratively large quantity was required for fatal effects in the guinea 
 pig. The larger amount necessary was partially accounted for by 
 the fact that' the material caused vomiting. In the guinea pig the 
 effects of the material appeared to be the same after subcutaneous or 
 intraperitoneal injection or after feeding. 
 
 The mixed alkaloids cause vaso-dilatation and apparently affect the 
 cardio-inhibitory center, slowing the heart action. Respiration was 
 slowed. After doses approaching the fatal quantity the heart-beat 
 becomes rapid and irregular and there is convulsive respiration. In 
 dogs the fatal dose given intravenously stopped the heart before 
 respiration ceased. When either injected or fed, it had a powerful 
 action both as a purgative and an emetic. 
 
 Later, in the Wyoming experiments, a more highly purified alkaloid 
 was obtained which could be crystallized from alcohol and benzene. 
 The crystalline material from benzene melted at 200-210 and was 
 found to have the formula C 39 H 63 N0 10 . The physiological action was 
 tested by Dr. Phillip Mitchell, who reported its effects to be different 
 from those found for the mixed alkaloids. Its behavior was in general 
 much like the alkaloid veratrine and it required comparatively large 
 quantities to kill guinea pigs. Unlike the mixed alkaloids it had no 
 noteworthy effect on the heart and apparently caused complete loss 
 of muscular control. 
 
 In 1918 Dr. C. A. Jacobson of the Nevada Station reported obtaining 
 a new alkaloidal product from Zygadenus paniculatus. This alkaloidal 
 product was designated by him as "Z-alkaloid." The crude alkaloid was 
 prepared by extracting the ground and dried plant with 95% alcohol, 
 concentrating the extract to a sirup and pouring into a dilute solution 
 of tartaric acid to remove resins and other impurities. The clear acid 
 solution was further purified by extraction with ether ; and the crude 
 alkaloid was precipitated by the addition of sodium carbonate. The 
 precipitate was an amorphous sticky mass poisonous to rabbits. The 
 liquid containing the precipitated solid matter was extracted with 
 ether. It was found that if the ether was completely removed on the 
 water bath, the material would then undergo violent effervescence and 
 the resulting product would no longer be poisonous. If, however, the 
 last of the ether was allowed to evaporate in the air at ordinary tem- 
 peratures no effervescence took place and the resulting material 
 retained its potency. Further purification was effected by re-solution 
 in tartaric acid, removal of impurities with ether, neutralization and 
 extraction with ether and chloroform. 
 
 The more purified Z-alkaloid had an increased toxicity, about 0.35 
 gram being found to be lethal for rabbits when administered by mouth. 
 
31 
 
 The Z-alkaloid, which constituted about 0.3% of the dried plant, was 
 soluble in ethyl and methyl alcohol, chloroform, acetone, and less so in 
 benzene and carbon tetrachlorid. On standing several months, it 
 resinified to a white substance without change in its toxicity or solu- 
 bility. On long standing, an alcohol-insoluble crystalline material 
 separated to the extent of about 1% of the original mass, but on account 
 of the small quantity obtained its physiological action could not be 
 determined. Various compounds of the Z-alkaloid were prepared ; and 
 from the data obtained it appeared that it is not the same as the com- 
 pound named Zygadinein which was obtained at the Wyoming station. 
 
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