SOME POISONOUS PLANTS. 
443 
SOME POISONOUS PLANTS.* 
WOOLLY LOCO WEED. 
Astragalus Mollissimus Torr. Other names: Loco Weed • Crazv- 
Weed (Fig. 8). > J 
Description and Where Found .—A silvery-white, silky-leaved 
perennial, 8 to 12 inches high, with an abundance of soft foliage 
springing out in a cluster from a short, central stem close to the 
ground. The flowers are pea-shaped and usually purple, the 
pod is distinctly two-celled. This plant is native to the Great 
Plains region, extending from western Texas and New Mexico 
northward to South Dakota and Wyoming, being most abun¬ 
dant in Colorado and in the western part of Nebraska and Kan¬ 
sas. It grows both on the open prairie and on rocky hillsides. 
How Stock are Affected .—Horses, cattle and sheep are 
affected by loco, but the principal damage is done to horses. 
The effect is not acute, but in its slow progress simulates dis¬ 
eases caused by bacteria, worms, or other parasites or such as 
are caused in man by the continued use of alcohol, tobacco, or 
morphine. Two stages are recognized. The first, which may 
last several months, is a period of hallucination or mania accom¬ 
panied by defective eyesight, during which the animal performs 
all sorts of antics. After acquiring a taste for the plant it re¬ 
fuses every other kind of food, and the second stage is ushered 
in. This is a lingering period of emaciation, characterized by 
sunken eye-balls, lustreless hair, and feeble movements. The 
animal dies from starvation, in periods ranging from a few 
months to one or two years. 
Damage Done .—The damage done to the live-stock business 
by this weed is immense. As mentioned in the introduction, 
the State of Colorado paid out nearly $200,000 in bounties be¬ 
tween 1881 and 1885 in an attempt to exterminate it. 
_ This genus contains a large number of species, and it is 
quite probable that many of these should be considered to be 
poisonous where they grow over wide areas of pasture land, and 
are green at periods when there is but little green grass. Over 
a half dozen have been reported to the Department of Agricul¬ 
ture as highly detrimental to the stock industry. 
* Abstracted from the Farmer’s Bulletin, No. 86, U. S. Dept. Agriculture, by W. T. 
Martin, M. D. C., Kankakee, Ill. 
