Description from Flora of China
Pterolobium indicum A. Richard var. macropterum (Kurz) Baker; P. sinense J. E. Vidal.
Climbers, woody, tall. Young branchlets striate, sparsely hairy; old branches glabrous, with blackish prickles in pairs at bases of petioles. Leaf rachis 8-10 cm; pinnae 4-6 pairs, 8-10 cm; rachis of leaves and pinnae densely brownish hispidulous, articulate; leaflets 6-9 pairs, opposite, obliquely oblong, 1.5-2 × 0.6-1 cm, leathery, both surfaces glabrous, base asymmetric, apex rounded, cuspidate, or emarginate. Racemes or panicles terminal or supra-axillary; rachis 10-15 cm, hairy; bracts subulate. Pedicels 5-10 mm. Sepals unequal, thickly leathery, smooth. Petals whitish, outer 4 equal, ca. 5 mm, obovate, innermost one abruptly contracted into a broad claw from middle downward, blade ciliate on margin, apex undulate, auriculate. Stamens equal in length, exserted; filaments ca. 8 mm, inflated and densely hairy from middle downward; anthers oblong, ca. 1 mm. Ovary slightly puberulent, 2-ovuled; style filiform, glabrous; stigma funnel-shaped, ciliate. Legume indehiscent, 6-6.5 cm; wings oblique, 4-4.5 × 1.8-2 cm, part containing seed ovoid. Fr. May, Oct.
Dry thickets, forests, sunny slopes; 400-1600 m. Guangxi, Hainan, Yunnan [Bhutan, India, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam].