Description from Flora of China
Trees, to 30 m tall. Branchlets brown, pubescent when young. Leaf rachis 30-60 cm; petiolar gland broadly elliptic, 4-6 mm; pinnae (11-)15-20 pairs, pinna rachis 10-15 cm, fulvous pubescent; leaflets sessile, 28-56 pairs, linear-falcate, 10-14 × 3-4.2 mm, rigidly leathery, both surfaces glabrous except ciliate along margin, lateral veins prominent abaxially, base subtruncate, unilaterally slightly auriculate, apex obliquely acute. Heads with peduncles 30-45 cm, several together racemiform. Flowers yellow. Calyx 8-10 mm; lobes orbicular, yellow tomentose. Corolla tubular, 10.5-11.5 mm; lobes ca. 1.5 mm, oblong, acute. Staminal tube 9-9.5 mm; anthers 1-1.5 mm. Ovary stipitate. Legume black, slightly torulose, (15-)30-45 × ca. 3 cm, glabrous, shiny, base attenuate into a stipe 12-22 cm, apex rounded. Seeds obliquely arranged, 6-15. Fl. Mar, fr. Sep-Nov.
Dry evergreen and mixed deciduous forests, thickets, along brooks; 500-600 m. Cultivated in Yunnan (Xishuangbanna) [native to Myanmar and Thailand].