UNITED STATES DEPARTMENT OJP i^RlCULTyg^T 
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BULLETIN No. 947 /*•'_ ._ V^D 
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Contribution from the Bureau of Animf 1 Ladustry * »ufc| Jr 
JOHN R. MOHLER, Chiei 
Washington, D. C. 
PROFESSIONAL PAP] 
WESTERN SNEEZEWEED (HELENIUM 
HOOPESII) AS A POISONOUS PLANT 
By 
C. DWIGHT MARSH, Physiologist in Charge of Investigations of 
Stock Poisoning by Plants; A. B. CLAWSON, Physiologist; JAMES 
F. COUCH, Pharmacological Chemist, and HADLEIGH MARSH, 
Veterinary Inspector, Bureau of Animal Industry , 
CONTENTS 
Page 
Introduction .....' 1 
Historical Summary 1 
Description of the Plant 3" 
Experimental Work 6 
Feeding Experiments With Sheep . . 11 
Feeding Experiments With Cattle . . 15 
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 
Toxicity of Leaves of Plant 32 
• Page 
Discussion, etc. — Continued 
Toxicity of Flowers 34 
Toxicity of Stem Leaves 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 . . 44 
Summary 45 
Literature Cited 46 
WASHINGTON 
GOVERNMENT PRrNTTNG OFFICE 
1921 
