Wooly Loco (Astragalus mollissimus)>


Wooly Loco Astragalus mollissimus Torr. (PEA FAMILY)

Wooly loco is a tufted, semidecumbent perrenial with whitish-gray pilose stems. The alternate leaves are pinnately compound with 21 to 31 obovate to ovate leaflets which are densely silky-pilose with yellowish hairs. The inflorescence is a dense raceme -4 in. long with violet to purple pea flowers. The legume is a glabrous pod 1/2 in. long or longer. This beautiful prairie wildflower is an unwanted guest on livestock ranches because of its highly toxic nature. One of the first green plants to appear in the spring, iit can become a part of cattle diets. Once they have eaten a small amount, they become addicted and seek it out. It is highly unpalatable, however, and they usually do not eat the plant. Wooly loco has an alkaloid that is slow to be metabolized by the animal which leads to an accumulation over time. The symptoms belie the name loco, in that the animals are usually in a disoriented state, nervous, and unable to eat or drink in severe cases. Horses are more affected than cattle or sheep.