Description
Raceme Milkvetch is a coarse, herbaceous perennial with few to many erect stems, 15-70 cm high, and arising from a woody taproot and branched rootcrown. The pinnately compound leaves are 4-15 cm long with 11-31 narrowly to broadly elliptic leaflets. Foliage is thinly to densely covered with short hairs. Inflorescences with 15-70 densely clustered flowers arise from the axils of the upper leaves. The nodding, whitish flowers are 16-21 mm long with a partially reflexed upper petal and purplish tinged lower petals. The calyx is 8-11 mm long and glabrous or with scattered hairs. The pendant, oblong-elliptic pods have a basal, 3-7 mm long stalk, are glabrous, triangular in cross-section, with 3 sides that are nearly flat and equal-width, and 15-30 mm long.
Diagnostic Characteristics
The combination of coarse, erect stems, short pubescence, and pendant pods, triangular in cross-section, is diagnostic of this species in the n. Great Plains. The more common A. DRUMMONDII is similar but has pods dorsiventrally compressed with 2 parallel grooves on the bottom, and has foliage with long spreading hairs.