UNITED STATES DEPARTMENT OF AGRICULTURE 
JEPARTMENT BULLETIN No. 1240 
Washington, D. C. T June 27, 1924 
THE MEADOW DEATH CAMAS (ZYGADENUS VENENOSUS) AS A POISONOUS 
PLANT. 
By C. Dwight Marsh, Physiologist in Charge, and A. B. Clawson, Physiologist, 
Investigations of Stock Poisoning by Plants, Pathological Division, Bureau of 
Animal Industry. 
CONTENTS. 
Page. Page. 
Importance of study of Zygadenus venenosus. 1 I Discussion and results 5- 
Description and distribution of the plant 2 Summary 13 
Experimental work 3 | Literature cited 13. 
IMPORTANCE OF STUDY OF ZYGADENUS VENENOSUS. 
While there is considerable difference of opinion among systematic 
botanists as to the number of species of the death camas (Zygadenus) 
which should be recognized, they are fairly well agreed on the four 
species most likely to be encountered by stockmen using the western 
ranges. These four species are grassy death camas, Z. gramineus; 
foothill death camas. Z. paniculatus; mountain death camas, Z. 
elegans; and meadow death camas, Z. venenosus. 
The general subject of death-camas poisoning, with special reference 
to Z. gramineus, wrongly identified at that time as Z. venenosus, was 
treated in Department Bulletin 125, United States Department of 
Agriculture. Department Bulletin 1012 gave the result of investi- 
gational work on Z. paniculatus and Z. elegans. During the summer 
of 1921 a special study of the true Z. venenosus was made. 
While Z. venenosus is nominally the subject of many papers, there 
has been much confusion in the use of the name, and many of the 
? publications under this name were evidently about other species, 
n the older publications it was much the fashion, because the plants 
were poisonous, to call the forms seen venenosus without attempting to 
discriminate between them. This has been particularly true of those 
publications which discussed the plants from the standpoint of their 
poisonous properties. It is safe to assume that in publications in 
regard to death camas in Montana, Wyoming, and Colorado the species 
referred to was not Z. venenosus but was in most cases Z. gramineus. 
So far as preceding experimental work is concerned, there are only 
two papers in which it can reasonably be assumed that this species 
was treated, viz, S. B. Nelson, 1906, and Fleming and coauthors, 
1921. x 
1 See references to literature e.t ena of bulletin. 
79737°— 24 
