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2 BULLETIN 1012,-U. S. DEPARTMENT OF AGRICULTURE. 
at that time was determined by systematic botanists as Z. venenosus. 
’ Later systematic work has shown that the species used was not the 
true venenosus, but was Z. gramineus. Of the other species used, 
Z. elegans and Z. coloradensis are so closely allied that they are 
considered by many #otanists as not specifically distinct. There is 
no question, however, of the specific distinction between Z. grami- 
neus, Z. elegans, and Z. paniculatus. From further work it seemed 
probable that there was a much greater difference in toxicity of the 
species than was apparent at the time Bulletin 125 was published, 
and it became a matter of considerable eae to determine the 
comparative toxicity of the different forms. 
All these species are so closely allied that they are not likely to be 
separated by anyone who has not a fairly good knowledge of botany, 
It follows, of course, that ordinarily all these forms are grouped under 
) 
the term “death camas” without perception of the difference be- 
tween the species. It is a matter of much scientific and practical 
interest to know how they differ. 
Z. pamculatus is the most widely distributed and is the most 
common form of death camas in the intermountain region and in 
part of the western slope. Z. elegans is not so abundant but is the 
common species on the higher mountain ranges of the West. Both 
Z. elegans and Z. paniculatus grow in considerable quantity in the 
neighborhood of the Salina Experiment Station, Utah, where a 
somewhat extended study of the plants has been made. The proof 
that these species are either more or less toxic than Z. gramineus, 
which grows in Montana, would be of very great practical importance 
to the stockmen who use the ranges where these plants are found. 
The experimental work was conducted on the same general lines as 
the work in Montana, and the results have proved to be of consider- 
able importance. Still further work is necessary on the species of 
this genus, but the results obtained regarding these two species are 
definite and conclusive. All the work here reported was done on 
plant material’ collected in Utah. Inasmuch, however, as experience 
with poisonous plants indicates that difference in locality has lttle 
effect on the degree of toxicity, the conclusions reached here un- 
doubtedly will apply equally well to these species wherever they may 
be found. It may be added that Zygadenus intermedius, on which 
work has been. done by other authors, is considered wy systematists 
as being identical with Zygadenus gramineus. 
ZYGADENUS PANICULATUS. 
DESCRIPTION AND DISTRIBUTION OF THE PLANT.2 
Zygadenus paniculatus, shown in Plate I, is an erect perennial herb 
with leafy stems arising from fibrous-coated bulbs. The linear leaves 
? The description of Z. paniculatus and its distribution was prepared by W. W. Eggleston, of the Bureau 
of Plant Industry. Mr. Eggleston has made a detailed study of the genus Zygadenus. 
