Climbers. Branchlets with sparse recurved prickles, puberulent. Leaves 15-20 cm; pinnae 5-8 pairs; rachis of leaves and pinnae pilose; leaflets 8-12 pairs, opposite, dispersed, subsessile, abaxially farinose-brown when dry, adaxially brown, shiny, oblong, 8-15 × 4-6 mm, papery, both surfaces glabrous, base obliquely truncate, apex truncate or obtuse-rounded, emarginate. Panicles axillary, 10-15 cm, brown puberulent. Pedicels 4-7 mm, jointed at apex. Flowers ca. 8 mm in diam. at anthesis. Sepals 5, glabrous, lowest one cucullate-lanceolate, ca. 6 mm, apex obtuse, other 4 ovate-oblong, slightly shorter, 3.5-4 mm. Petals obovate-oblong, 3.5-4 mm, pubescent, shortly clawed. Stamens 10; filaments ferruginous pilose at base. Ovary elliptic, glabrous, 2-ovuled. Legume blackish when dry, ovoid or elliptic, ca. 5 × 2.3-3 cm, thin, swollen at maturity, concave, ventral suture narrowly winged, 1-seeded. Fl. Jul-Sep, fr. Aug.