DEATH CAMAS SPECIES, ZYGADENUS ELEGANS. 25 



0.07 pound of seeds, or almost exactly one-half the dose of the whole 

 fruit head. 



Drying experiments make it possible to figure the doses of various 

 parts of the plant given in terms of dry material. Inasmuch as the 

 seeds fed were dry, this is desirable in making comparisons of relative 

 toxicity of seeds and other portions of the plant. When this is done 

 it appears that with Z. paniculatus the seeds are twice as toxic as the 

 fruit heads and four times as toxic as leaves, stems, and flowers, while 

 the fruit heads are about twice as toxic as leaves, stems, and 

 flowers. That this ratio does not hold with Z. elegans is shown by 

 the feeding of 0.463 pound of dry fruit heads and 0.807 pound of seed 

 without effect when 0.623 pound was found to be a toxic dose of dry 

 leaves, stems, and flowers. In other words, fruit heads or seeds of 

 Z. elegans are little if any more toxic than leaves, stems, and flowers. 



Z. ELEGANS NOT ESPECIALLY DANGEROUS FOR SHEEP. 



If sheep were to graze on Z. elegans they would rarely get the 

 bulbs, although these can sometimes be pulled up, as the plant grows 

 in wet ground and the bulbs are not far from the surface. The feed- 

 ing would be largely on the aerial parts of the plant, and of these it is 

 thought that the fruit and seeds would seldom be eaten, as they are 

 dry and unattractive. Of the parts of the plant likely to be eaten it 

 would take from 1.5 pounds to between 3 and 4 pounds per 100 pounds 

 of animal to poison an animal and 6 pounds to produce a fatal effect. 

 It follows that poisoning from Z. elegans is not likely to occur, as 

 sheep would seldom eat so large a quantity. Moreover, Z. elegans 

 grows in localities where there is ordinarily an abundance of vegeta- 

 tion, so that animals would not be forced to eat it because of a lack 

 of other forage. While both Z. gramineus and Z. paniculatus may 

 and do cause losses, Z. elegans can be hardly be reckoned as an impor- 

 tant poisonous plant; in fact, it is doubtful whether it causes any 



losses on the range. 



SUMMARY. 



1. In preceding investigations of the species of Zygadenus, known 

 popularly under the collective name of "death camas," little atten- 

 tion has been given to the comparative toxicity of the various species. 



2. Detailed studies of Z. paniculatus and Z. elegans, compared with 

 preceding work with Z. gramineus, have shown a marked difference in 

 toxicity. 



3. Z. paniculatus is found to be about one- third as toxic as Z. 

 gramineus, and Z. elegans about one-seventh. 



4. While Z. paniculatus is not so toxic as Z. gramineus, it is a 

 distinctly dangerous plant, and is the cause of heavy losses of live- 

 stock. Z. elegans, however, while it may poison livestock, probably 

 does little or no damage under practical range conditions. 



