Dioecious, small to medium-sized tree, up to 20 m tall; bole rarely straight, up to 60(–220) cm in diameter; bark pale red-brown, flaky; crown wide, umbrella-shaped; young branches densely covered with short, villous hairs and long, erect, silvery, soft, often glandular hairs turning reddish-green, with ring-like, long persisting leaf scars. Leaves alternate, imparipinnate, up to 50 cm long; petiole up to 15 cm long, with 2, up to 1.5 cm wide, thin, leafy lateral wings (adnate stipules) at base surrounding the twig as a sheath; leaflets up to 17, alternate to subopposite, subsessile, narrowly oblong to elliptical, 9–15 cm × 2–5 cm, obliquely obtuse at base, acuminate at apex, margin serrate and long silky hairy, the teeth usually ending in a thickened gland, pinnately veined with veins prominent below and having long silky hairs; much smaller, suborbicular leaflets up to 2.5 cm in diameter may occur alternating with the normal leaflets. Inflorescence a terminal, drooping, much-branched, many-flowered panicle up to 60 cm × 30 cm, yellowish, often bright red tinged; branches villous to long silky hairy, sticky, subtended by leafy bracts, rachis usually zigzag. Flowers unisexual, regular; pedicel up to 3.5 mm long, densely hairy, subtending bracts clasping the pedicel at base, bracteoles reniform; hypanthium a conical, silky hairy tube 2–3 mm long, with 2 whorls of (4–)5 green or reddish tinged lobes (epicalyx and calyx), in male flowers epicalyx lobes smaller than calyx lobes, in female flowers larger and enlarging up to 10 mm long in fruit; petals (4–)5, vestigial, up to 1.5 mm long, alternating with the calyx lobes; stamens 15–20, filaments up to 3 mm long in male flowers, in female flowers rudimentary; pistils usually 2, free within the hypanthium, ovary with a tuft of hairs at top, style subfiliform, stigma capitate, usually only one ovary per female flower developing to fruit, in male flowers functionally sterile. Fruit a globose to ovoid achene up to 2.5 mm in diameter, with a thin, papery, pale to brown pericarp, white-hairy at top, enclosed by the dry persistent hypanthium with the epicalyx serving as wings. Seed subglobose to subovoid, only slightly smaller than the fruit, usually with a wrinkled, brown, glabrous testa.