Description from Flora of China
Trees. Leaves abruptly pinnate; stipules caducous, minute; leaflets in few pairs. Panicles terminal; bracts and bracteoles deciduous or ± persistent, ovate, slightly thick, not colored. Flowers bisexual, pedicellate. Calyx tubular, with a disk in throat; lobes 4, slightly unequal in size, leathery, imbricate. Petal 1, suborbicular or reniform, clawed, others rudimentary or absent. Stamens 7 or 8; filaments elongated, base partly united or free; anthers ovoid or oblong, opening lengthwise; staminodes 2, very small. Ovary stalked, stalk adnate to calyx tube; ovules few to numerous; style filiform; stigma subcapitate, small. Legume slightly compressed, oblong or obliquely oblong, woody, thick, 2-valved, transversely septate between seeds. Seeds ovoid or oblong, with horny, hard, arilloid funicle at base, without endosperm; cotyledons fleshy, ± flat; embryo straight.
About 14 species: tropical Asia and Africa; one species (introduced) in China.
(Authors: Chen Dezhao (陈德昭 Chen Te-chao), Zhang Dianxiang (张奠湘); Ding Hou)