UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 947 



Contribution from the Bureau of Animal Industry 

 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. CLAWSON, Physiologist; JAMES 



F. COUCH, Pharmacological Chemist, and HADLEIGH MARSH, 



Veterinary Inspector, Bureau of Animal Industry 



CONTENTS 



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 46 



Literature Cited 46 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1921 



