Whorlbd Milkweed 
7 
weed problem is one of considerable importance both from the 
standpoint of stock-poisoning and from the difficulties of eradica- 
tion which it presents. It deserves the continued attention of 
stock owners, farmers, and experimental workers. 
HOW IT MAY BE mENTIEIED 
The plant under discussion belongs to the group of milk- 
weeds having verticillate or whorled leaves which are linear 
in outline. There are three common members of this group, 
Asclepias verticillata, A. galioides and A. pumila. A. pumila is much 
smaller than the other two, seldom being over a foot 
high, and having very fine leaves. (Fig. 3). A-galioides and A. 
L<''ig’. 3 — Low milkweed (Asclepias pumila) 
not known to be poisonous. 
verticillata are much more nearly alike. In Bulletin No. 246 of 
this Station, published in July, 1918, the plant which has 
been responsible for the losses of livestock in Colorado was called 
A- verticillata. This bulletin was issued as an information bul- 
letin to call attention of stockmen to the poisonous nature of the 
