2 BULLETIN 942, IT. S. DEPARTMENT OF AGRICULTURE. 
branching, are 3 to 12 inches high, tufted, and puberulent. The 
main root is horizontal, branching, and produces adventitious buds. 
Figure 2 of Plate I shows plants growing from adventitious buds 
on the root. The leaves, which are 1 to 2 inches long, are sessile, nu- 
merous, crowded, and irregularly alternate to verticillate, linear- 
foliform, revolute, and scabrous-puberulent. The flowers are in 
terminal branching umbels, few to many flowered, with short pedun- 
cles, and are scabrous-puberulent. The greenish-white corolla has 
oblong lobes and white oblong hoods, which are hastate-sagittate in 
back view and shorter than the horn. The follicles are erect, puberu- 
lent and H to 3 inches long. The plant is found in adobe draws, in 
Fig. 1. — Distribution of Asclepias pumila. 
dry plains, and in foothills from southeastern Montana and south- 
western North Dakota to the Texas Panhandle and central New 
Mexico. It is most abundant on the plains of Colorado. 
Text figure 1 shows the distribution of the plant. Although it has 
a root system and seeds similar to Asclepias galioides, it has not 
spread widely. It usually is scattered in small patches in draws. 
The systematic position of Asclepias pumila is discussed in United 
States Department of Agriculture Bulletin 800. pages 5 and 6. 
EXPERIMENTAL WORK WITH A. PUMILA. 
All experimental work which was carried on in the summer of 
1919 was with sheep, and the material in all cases was administered 
by the balling gun. 
