Stems herbaceous, slender, wide-twining, slightly tawny-bristly. Stipules minute, ovate acuminate. Petioles 1 1/2–2 in. long, slender, thinly bristly; leaflets 3, the central one ovate-lanceolate, 1 1/2–2 1/2 in. long, the upper half narrowed gradually to a point with a mucro; petiolule 4 lines long; lateral ones slightly unequal-sided, upper surface glabrous, lower thinly-bristly when young. Flowers 2–4 on densely bristly peduncles about an inch long. Calyx campanulate, glabrous, 2 lines deep, the two upper teeth connate, deltoid, the three others lanceolate acuminate, reaching quite halfway down. Corolla rose-red, twice as deep as the calyx; keel truncate. Pod 1 1/2 in. long, under 1/4 in. thick, subterete, hispid.