Description
Cicada milkvetch is a stemless (or nearly so) perennial herb with a simple or branched rootcrown and taproot. The pinnately compound leaves are 2-8 cm (1-3 in) long with 2-7 pairs of egg-shaped leaflets. Foliage is covered with silvery hairs that branch at the base and spread in opposite directions appressed to the surface of the leaf or stem (dolabriform). 4-9 flowers are borne on lax or ascending stalks arising from near the top of the rootcrown. The purplish, pea-like flowers have a slightly raised upper petal, 16-25 mm long, that is just barely longer than the others. The purplish calyx is 9-13 mm long and covered with white or black hairs. The brightly mottled, green and purple, inflated fruits are sparsely hairy and egg-shaped with a short, flattened beak and usually lay directly on the ground among the leaves.
Diagnostic Characteristics
The combination of stemless habit, dolabriform hairs and mottled, inflated pods distinguish this species. A hand lens or microscope is required to observe the hairs.