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UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1391 
Washington, D. C. 
May, 1926 
RAYLESS GOLDENROD (APLOPAPPUS HETEROPHYLLUS) AS A POISONOUS 
PLANT 
By C. Dwight Marsh, Associate Physiologist in Charge of Investigations of 
Stock Poisoning by Plants, GxenwoOd C. Roe, .Junior Physiologist, and A. B. 
Clawson, Associate Physiologist, Pathological Division, Bureau of Animal 
Industry 
CONTENTS 
Page 
Historical introduction 1 
Description of the plant 5 
Experimental work 6 
Typical case of steer No. 851__ 10 
Typical case of sheep No. 589__ 11 
Discussion and general conclusions- 13 
Symptoms . _ 13 
Examinations of urine 14 
Autopsy findings 15 
Microscopic changes in tissues- 15 
Toxic and lethal dosage 18 
Duration of sickness 20 
Page 
Discussion and general conclusions — 
Continued. 
Aplopappus a cumulative poison_ 21 
Transmission of the poison by 
milk 21 
Effect of exercise on animals 22 
Effect of sterilized plant 23 
Effect of eating grass with the 
Aplopappus 23 
Destruction of the plant 23 
Summary 24 
Literature cited 24 
HISTORICAL INTRODUCTION 
The possible poisonous properties of ray less goldenrod Aplopap- 
pus heterophyllus (A. Gray) Blake, 1 were first brought to the atten- 
tion of the Department of Agriculture in 1905, in a letter written by 
E. O. Wooton, then at Mesilla Park, 1ST. Mex. He sent a specimen of 
the plant and stated that it was reported as a plant poisonous to 
cattle and horses if it had been frosted. One man was reported to 
have lost 22 horses in 10 days, just after the plant had been frosted. 
Other animals in the same pasture, however, were not affected. It 
was stated also that the horses did not eat it until after it had been 
frosted. Mr. Wooton wrote again to the department in 1907, refer- 
ring to the belief among some of the stockmen that the plant made 
milk poisonous. It appears to have been thought by many at that 
time that the plant was the cause of the disease known throughout 
the Pecos Vallev as alkali disease or milk sickness. 
E. L. Moseley, (7) 2 in May, 1909, published in the Medical Eecord 
an article on the cause of "trembles" or "milk sickness/* in which 
Formerly called Isocoma wrightii. 
Reference is made by number (italic) to "Literature Cited," paj 
69608' 
