Stems: angled, winged, slender. Leaves: leaflets two to four pairs, lanceolate, oblong, pointed at the apex, rounded at the base. Flowers: style dilated and flattened above, hairy along the inner side. Fruit: pod flat, seeds globular.
The purple flowers of this plant grow in loose-headed racemes where the ground is moist. The slender stems are angled and winged, the three or four pairs of leaflets are oblong and pointed, and the tendrils terminating the stalks are branched.