Agric. -Hqresiry. Main 



UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No v 1012 



Contribution from the Bureau of Animal Industry 

 JOHN R. MOHLER, Chief 



r ashington, D. C. 



PROFESSIONAL PAPER 



April 17, 1922 



HE DEATH CAMAS SPECIES, ZYGADENUS PANICULATUS 

 AND Z. ELEGANS, AS POISONOUS PLANTS. 



C. DWIGHT MARSH, Physiologist in Charge of Investigations of Stock Poisoning by 

 Plants, and A. B. CLAWSON, Physiologist, Pathological Division. 



'urpose and scope of paper 



Zygadenus paniculatus 



Description and distribution of plant . . . 



Experimental feeding 



Mscussion and results 



Symptoms 



Duration of symptoms 



Time required to produce symptoms . . . 



Toxic and lethal dosage 



Zygadenus elegans 



Description and distribution of plant 



Experimental feeding 



CONTENTS. 



Page. 



2 

 2 



3 



10 

 10 

 12 

 13 

 13 

 16 

 16 

 17 



Page. 



Discussion and results 20 



Symptoms 20 



Duration of symptoms 2] 



Time required to produce symptoms.. . 



Results of autopsy 



Toxic and lethal dosage 



Comparative toxicity of Z. gramineus, Z. 



paniculatus, and Z. elegans 



Z. elegans not especially dangerous for 



sheep 



Summary 



PURPOSE AND SCOPE OF PAPER. 



In Bulletin 125, United States Department of Agriculture, page 

 55, the following statement was made with regard to the comparative 

 >xicity of different species of Zygadenus: 1 



In the course of the experiments four species of Zygadenus were used Z. venenosus, 

 ' . elegans, Z . paniculatus, and Z . coloradensis by far the greater part of the work be- 

 lone with Z. venenosus. The number of experiments with Z. elegans and Z. pani- 



ilatus was very small, and the material, especially in the case of Z. paniculatus, had 



m shipped a long distance, so that there was some question of the water content 

 ! theplant. Apparently, however, Z. elegans smd Z . paniculatus do not differ materially 



toxicity from Z. venenosus. Z. coloradensis, however, produced no toxic effects 

 whatever, with the exception of slight symptoms in one sheep, although the plant 

 ^as fed in quantities several times as great as the toxic dose of Z . venenosus. 



It is evident that in the feeding of cattle with Z. coloradensis at Mount Carbon in 

 [909, the results of which are given in Table I, the quantities fed were too small to 

 produce results, even if the plants were as poisonous as Z. venenosus. In the experi- 



?nt of 1910, however, a large quantity was fed, and sufficiently large quantities in 



igle days' to produce symptoms of poisoning if the plant were as toxic as Z. venenosus. 



Most of the work reported in Bulletin 125 was on the species of 

 Zygadenus growing in the Yellowstone Valley, Montana, which 



1 Zygadenus, or Death Camas by C. Dwight Marsh, A. B. Clawson, and Hadleigh Marsh, Bulletin 125, 

 Jnited States Department of Agriculture, 1915. 

 67283 22 Bull. 1012 1 



J 



