Description from
Flora of China
Pithecellobium sect. Samanea Bentham, London J. Bot. 3: 197, 215. 1844.
Trees, large, unarmed, with spreading crown. Leaves bipinnate; stipules deciduous, lanceolate; pinnae 3-6 pairs, with glands between pinnae on rachis; leaflets opposite. Inflorescences axillary corymbs, pedunculate; bracts small. Flowers dimorphic; central flowers enlarged, 7- or 8-merous; marginal flowers smaller, 5-merous. Calyx shortly lobed. Petals connate to middle. Stamens many, united at base into a tube; anthers not glandular. Ovary sessile; style filiform; ovules many. Legume straight or slightly curved, turgid with thickened margins, woody, indehiscent, septate between seeds. Seeds numerous, strongly biconvex, with pleurogram; aril absent.
Three species: mainly around the Amazon and in Central America; one species (introduced) in China.