Climbers, woody. Young branchlets pubescent and glandu­lar hairy, glabrescent when old. Stipules linear to filiform, 2-3 cm; petiole 2.5-6.5 cm; glands at or above middle, elliptic and raised, rarely flat; pinnae 8-20 pairs, rachis 2-12 cm; leaflets 19-81 pairs, oblong, (2-)3.5-7.5 × 0.8-1.5 mm, both surfaces glabrous, except ciliate along margin, midvein close to upper margin, base truncate, unequal, apex obtuse, straight. Heads globose, arranged in terminal or axillary panicles. Flowers sessile or subsessile. Calyx 1.7-2.9 mm, glabrous, puberulent, or velutinous, 5-toothed. Corolla light yellow, 2-4.2 mm, gla­brous or puberulent; lobes oblong or narrowly obovate, 0.8-1.1 mm. Stamens numerous. Ovary sericeous, shortly stipitate. Leg­ume red-brown, oblong, flat, 9.5-17 × 1.3-3.5 cm, papery, glabrous. Seeds brown, ovoid-ellipsoidal to ellipsoidal, flat, 7-9 × 4.5-5.5 mm. Fl. May-Jun, fr. Sep-Oct.

Thin forests, thickets; 800-1600 m. Guangxi, Yunnan [widely dis­tributed in tropical Asia].