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 



