The leaves are the most distinctive element of astragalus missouriensis
, being thick, oval, (often) bent along the axis and covered with long white hairs, so that the plant has an overall grey-green appearance. Hairs are appressed, lying close to the leaf surface. Flowers (3 to 10) grow at the end of short thick stems; they and the calyx tube also have a coating of white hairs. The petals range in color from blue to deep purple to (less commonly) very pale purple, with a white patch at the center. Flowers measure up to 1 inch in length.
The plant inhabits a wide range, from Canada to Texas and New Mexico, and four varieties are recognized (amphibolus, humistratus, mimetes and missouriensis).