Woody climbers, young parts pubescent. Leaf rachis 6-15 cm; stipels linear, 7-8 mm; leaflets subrhombic, elliptic, or ovate, 8-14 × 6-12.5 cm, lateral ones smaller than terminal one, appressed pubescent abaxially, glabrous adaxially, base rounded, apex acuminate. Racemes 30 cm or more. Bracts ovate-lanceolate, 7-8 mm, ciliate; bracteoles 5-7 mm. Calyx campanulate, 4-lobed; tube 4-5 mm; lobes 7-12 mm. Corolla purplish, 10-18 mm. Legumes blackish, 10-12 × 2.5-3 cm, thinly leathery, glabrous. Seeds brown, reniform, ca. 5 × 2.5 mm.