UNITED STATES DEPARTMENT OF AGRICULTURE 
U| BULLETIN No. 947 AA 
kl|>^il,y Contribution from the Bureau of Animal industry ^aliu^<JKSr 
JOHN R. MOHLER, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
October 11, 1921 
WESTERN SNEEZEWEED (HELENIUM HOOPESII) 
AS A POISONOUS PLANT. 
By C. Dwight Marsh, Physiologist in Charge of Investigations of Stock Poisoning 
by Plants; A. B. Claw son, Physiologist; James F. Couch, Pharmacological 
Chemist; and Hadleigh Marsh, Veterinary Inspector, Bureau of Animal Industry. 
CONTENTS. 
Page. 
... 1 
... 1 
... 3 
... 6 
... 11 
... 15 
Introduction. 
Historical summary 
Description of the plant 
Experimental work 
Feeding experiments with sheep 
Feeding experiments with cattle , 
Chemical examination of the plant 17 
Urine examination 23 
Discussion and general conclusions 24 
Symptoms 24 
Autopsy findings 27 
Pathology of H. hoopesii poisoning 27 
Toxic dose for sheep 30 
Toxic dose for cattle 30 
Acute cases 31 
Page. 
Discussion, etc.— Continued. 
Toxicity of leaves of plant 32 
Toxicity of flowers 34 
Toxicity of stemleaves 34 
Comparative toxicity of different parts of the 
plant 34 
Effect of drying on toxicity of leaves 35 
Seasonal variation in toxicity of the plant ... 36 
Permanent effect produced by the poison — 37 
Remedies 38 
Treatment of plant on the range 39 
Practical suggestions for stockmen on the 
range 44 
Summary 45 
Literature cited 46 
INTRODUCTION. 
HISTORICAL SUMMARY. 
In 1903, V. K. Chesnut, who was at that time in charge of poisonous- 
plant investigations in the Department of Agriculture, while visiting 
Sevier County, Utah, was told that a disease of sheep was prevalent 
in that part of the State. The disease was characterized by vomiting 
and wasting away, the sheep dying after a time varying from a week 
or two to a month. Nothing further was heard of this disease by 
the department until January, 1911, when the senior author, who 
was making an address to the stockmen of Salina, L T tah, was told 
that the sheep on the summer ranges in the Wasatch Mountains 
28468°— 21— Bull. 947 1 
