Plants 20-90 cm tall, with symmetrically or asymmetrically bifurcate appressed hairs 0.3-0.8 mm, often with mostly ± spreading, longer, basifixed hairs mixed in. Stems mostly several, prostrate or ascending to erect, hollow, 2-6 mm thick, glabrous or sparsely to rather densely covered with medifixed hairs. Leaves 4-20 cm; stipules shortly connate behind stem or up to 1/4 of length, sparsely white and black hairy; petiole 0.5-3.5 cm, like rachis sparsely to rather densely covered with medifixed hairs up to 2 mm and sometimes sparsely with spreading basifixed hairs; leaflets in 10-17 pairs, narrowly elliptic, 5-23 × 3-13 mm, abaxially loosely to rather densely covered with appressed, medifixed hairs, adaxially glabrous or rarely with very few long basifixed hairs, rounded at apex. Racemes dense, ± umbellate-globose, 8-20-flowered; peduncle 4-15 cm, sparsely to loosely covered with appressed, medifixed hairs and sometimes also longer, ± spreading, basifixed, white hairs; bracts 4-8 mm, glabrous or ciliate. Bracteoles 2-3 mm. Calyx 5-8 mm, sparsely to loosely covered with predominantly black, very short, sometimes also longer hairs up to 0.5 mm; teeth 2-3.5 mm. Petals dark purple to blue-purple or more rarely ?yellow or standard and keel purplish and wings white; standard obovate, 10-14 × 4-6.5 mm; wings 9-12 mm; keel 8-10 mm. Legumes sessile, linear, 15-30 mm, 2.5-4 mm high and wide, with a short straight beak, incompletely 2-locular.