Description from Flora of China
Woody climbers. Young branchlets puberulent, glabrescent. Stipels subulate, 2-3 mm; petiolules 3-5 mm, glabrous or sparsely hairy; leaflets equal in shape, oblong, elliptic, or broadly obovate, 7.5-13 × 3-6 cm, leathery to thickly leathery, glabrous or ± puberulent abaxially, glabrous and shiny adaxially, midrib raised abaxially, flat or slightly impressed adaxially, lateral veins slightly raised on both surfaces, veinlets obscure, base rounded, apex acuminate or rounded and with a short blunt mucro. Panicles axillary, solitary or 2 or 3 fascicled, sparsely brownish puberulent or glabrescent. Pedicels as long as or slightly shorter than calyx; bracteoles linear, caducous. Calyx ca. 4 mm; teeth bluntly triangular, 1.5-2 mm, sparsely puberulent outside, slightly hairy inside. Corolla purplish red; standard orbicular, 5-6 mm in diam., apex emarginate; wings and keel oblong, subequal in length, apex rounded, base with a rounded auricle on one side. Anthers equal in size. Ovary sessile, hairy. Legumes 8-9 cm, 2.2-2.5 cm wide in lower part, 1.6-1.8 cm wide in upper part, adpressed brownish puberulent, apex obtuse, without stipe. Seeds blackish, dull, oblong or narrowly elliptic, 1.9-2.9 × 1-1.3 cm. Fl. Mar, fr. Jun-Jul.
Sparse forests, streamsides. Hainan (Baisha, Danxian) [Laos, Vietnam].