Trees, evergreen, ca. 10 m tall; branches glabrous. Leaves trifoliolate, sometimes simple leaves on upper branches, glabrous; petiole 1-9 cm, base swollen; petiolule 0.5-3 cm; leaflet blades narrowly oblong to oblong-lanceolate, 5-17 × 2.8-6 cm, abaxially pale, with prominent lateral veins, base cuneate, margin crenately serrate, apex acuminate. Plants dioecious. Panicle terminal or subterminal, 20-30 cm, glabrous; bracts and bracteoles small, deltoid, caducous. Male flower with sepals 4 or 5, imbricate, glabrous, sometimes margin ciliate, 1-1.5 mm; petals 4 or 5, subspatulate, yellowish or white, 2-3 mm; stamens 4 or 5, anthers oval, white; gynoecium vestigial. Female flower with sepals 4 or 5, oblong to oval-oblong, 2-3 mm; petals yellowish or white, 3-4 mm; stamens 4 or 5; ovary globose to ovoid, ca. 1 cm in diam. Seeds black or dark brown, lustrous.

Forests. Taiwan [S Japan].