Climbers. Branchlets brownish, glabrous, angulate, with short straight or slightly recurved prickles. Leaf petiole short, spinose; pinnae 3-5 pairs, 14-20 cm; leaflets dense, linear, 6-7 mm, less than 2 mm wide, glabrous, base obtuse or auriculate, apex obtuse. Heads solitary or paired, axillary, globose, ca. 1 cm in diam.; peduncles 3-4 cm. Calyx ca. 2 mm; lobes ca. 0.4 mm, apex acute. Corolla 3-3.5 mm; lobes ca. 1 mm, glabrous. Stamens ca. 2 × as long as corolla. Ovary ca. 1 mm, velutinous; stipe ca. 1.5 mm. Legume oblong, very flat, 8-10 × 2-3 cm, subleathery, both ends subrounded or obtuse, dehiscent. Seeds 7-9, gray, oblong-rhombic, flat. Fl. Jul, fr. Sep.

● Mountains, secondary forests; 1500-2200 m. Guizhou, Yunnan.