EUPATORIUM URTICAEFOLIUM AS A POISONOUS 
PLANT 
By C. Dwight Marsh, Physiologist in Charge , and A. B. Clawson, Physiologist , 
Poisonous Plant Investigations t Pathological Division, Bureau of Animal Industry , 
United States Department of Agriculture. 
INTRODUCTION 
Among the suggested causes for the disease popularly known as milk 
sickness, trembles, slows, tires, etc., has been the plant commonly called 
white snakeroot (Eupatorium urticaefolium, the Eupatorium ageratoides 
of the older literature). Arguments have been advanced in extenso both 
for and against this theory. In later years the possibility of the connec¬ 
tion of this plant with the disease has lessened since Crawford (4 ) 1 in 
1908 published his negative pharmacological work and Jordan and 
Harris (7) in 1909 published their paper on the Bacterium lactimorbi . 
While there have still been authors who clung to the white snakeroot origin 
of the disease, it has been rather generally believed that the real cause 
was not a plant poison but more likely a disease-producing germ. 
Although the investigation of the subject has been carried on by the 
Department of Agriculture for some years, little attention has been paid 
to the question of the connection of this plant with the disease, as it was 
thought probable that it should be disregarded. 
In the fall of 1914 there were some cases of milk sickness near Beecher 
City, Ill., and the attending physician, Dr. E. R. Brooks, made some 
experiments with the E. urticaefolium which led him to think it to be 
connected with the disease. At his solicitation a representative of the 
department visited the neighborhood, and arrangements were made to 
conduct a series of feeding experiments with a view to determine, if pos¬ 
sible, whether or not the plant produced the disease. The experiments 
were carried on during the fall and winter of 1914 and 1915 at Wash¬ 
ington and during the fall of 1915 near Beecher City. The material used 
in the first season was collected by Dr. Brooks and shipped to Washington, 
where it was fed both in fresh and dried condition. All the material 
used in the fall of 1915 was fed fresh from the immediate neighborhood 
of the experiment. 
The general results of the experiments in their relation to the disease 
of milk sickness are not in form for publication, but it has been clearly 
demonstrated that E. urticaefolium must be counted as one of the rather 
important stock-poisoning plants, which produces serious losses of domes¬ 
tic animals. On this account it seems wise to publish the results so far 
1 Reference is made by number (italic) to “Literature cited,” p. 714. 
Journal of Agricultural Research, 
Washington, D. C. 
lh 
(699) 
Vol. XI, No. 13 
Dec. 24, 1917 
Key No. A— 33 
