Herbaceous vine, twining, attaining 5-6 m in length. Stems obtuse-pentagonal or cylindrical, puberulent. Leaves alternate, trifoliolate;leaflets chartaceous, the apex acute or short-acuminate, the margins sinuate;upper surface dark green, dull, glabrous, with slightly prominent venation;lower surface pale green or glaucous, glabrous, with the primary and secondary venation prominent;terminal leaflet 5.5-11 ? 3.5-7.5 cm, rhombic or deltate, the base cuneate or truncate;lateral leaflets asymmetrically deltate, the base truncate;petiolules thickened, 3-5 mm long, pubescent;rachis 1.5-2.5 cm long;petioles 6.5-9 cm long, sulcate, puberulent, the base slightly broadened. Inflorescences of axillary pseudoracemes, erect, 3-30 cm long, the flowers in groups of 2 per node of the inflorescence;pedicels 6-9 mm long, pilose;bracteoles minute, oblong. Calyx 2-2.5 mm long, green, campanulate, pilose, the sepals deltate, subequal;corolla white or lilac, pink or bluish, the standard semicircular, 7-10 mm long, abaxially pilose, the wings obovate, unguiculate, as long as the standard, the keel spirally twisted, ca. 1 cm long;stamens 10, diadelphous, the vexillar stamen broadened at the base;ovary with hispidulous pubescence, intermingled with uncinate hairs. Fruit an oblong-falcate legume or in the form of a half-moon, flattened, 5-7 ? 1-2 cm, puberulent with uncinate hairs or glabrescent, dehiscent by valves that open in a spiral containing 2Ð4 seeds. Seeds reniform, flattened, approximately 7 mm long, reddish brown, with dark spots (Acevedo-Rodr’guez, 2005).