BULLETIN OF THE 



No. 125 



Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief 



and the Bureau of Animal Industry, A. D. Melvin, Chief. 



May 13, 1915. 



(PROFESSIONAL PAPER.) 



ZYGADENUS, OR DEATH CAMAS. 



By C. Dwight Marsh and. A. B. Clawson, Physiologists, Drug-Plant and Poisonous- 

 Plant Investigations, and Hadleigh Marsh, Veterinary Inspector, Bureau of Ani- 

 mal Industry. 



INTRODUCTION. 



HISTORICAL SUMMARY AND REVIEW OF LITERATURE. 



Chesnut and Wilcox (1901, p. 52) 1 say that "the earlier explorers 

 of the Western, and especially of the Northwestern, United States fre- 

 quently mention the poisonous character of the bulbs of one or the 

 other of the various species of Zygadenus and refer to them as poison 

 camas or poison sego in order to distinguish them from bulbs of two 

 other groups of plants, Quamasia and Calochortus, which were com- 

 monly known as camas and wild sego and were much used for food, 

 both by the Indians and by travelers. Accounts of the poisoning 

 of stock from eating the roots and leaves of various species have but 

 recently been sent to this Department." 



This statement, perhaps, covers the knowledge of the subject up 

 to that date, although the writers have failed to find much in the 

 way of definite statement among the earlier writers that can be re- 

 ferred to this plant. 



In Wyeth's journal of his second expedition to Oregon (Wyeth, 

 1899) occurs this statement: 



16th. Made down the Sandy S. W. by W. 15 miles then 4 S. E. by E. and camped 

 on this stream so far the grass is miserable and the horses are starving and also at last 

 night's camp they eat something that has made many of them sick the same thing 

 happened two year since on the next creek west. 



This happened on June 16, 1834, somewhere between Big Sandy 

 Creek and Leckie, in Fremont County, Wyo. The present knowl- 

 edge of the botany of that region makes it almost certain that the 

 poisonous plant in that place at the time of year mentioned must 



1 For the complete titles of works cited, see the list of literature on pages 45 and 46. 



Note.— This paper is intended to supply general information on the relation of Zygadenus to the losses 

 of live stock on the western stock ranges; it is suitable for distribution throughout the western third of 

 the United States. 



47698°— Bull. 125—15 1 



