Oxytropis, or locoweeds, have flowers in usually quite compact clusters, on stalks that rise from the base of the plant. The flower color is usually white or cream to reddish or purple. The calyx is 5-toothed. The banner is commonly bent straight up, the wings usually exceeding the keel in length. The keel is prolonged into a point or tooth or generally into a straight or curved beak, this is a distinctive feature of the genus Oxytropis. The plants are perennials, often tufted, with no or with short leafy stems. The leaves are odd-pinnate, with leaflets mostly in pairs plus one leaflet at the end. The stipules are more or less joined to the leaf stalk and often joined around the stem as well. The genus has about 300 species, chiefly in western N. America and Siberia. The name Oxytropis comes from the Greek oxys, sharp, and tropis, keel, referring to the beaked keel.
Locoweed is the common name for several species of plants of the family Fabaceae or Legume. Native to Western North America, some locoweed species cause locoism, a disease of the nervous system in animals, especially cattle. The disease, which is characterized by hallucinations, slow gait, and lusterless hair, can possibly cause death. Locoweeds are members primarily of the genus Oxytropis, but only a few species in each genus cause locoism. Because some species accumulate selenium, their occurrence may serve as an indicator of the rare and industrially important element found in soils. Selenium is a poisonous element in any large quantities, and should be handled with caution. Animals seldom eat locoweed unless drought or overgrazing forces them to, then they may become habituated and search for more, even when tastier forage is available.