Tree up to 10 m. tall; trunk usually armed with aculeate corky bosses; young branches and inflorescences minutely pubescent or glabrous; stems and the rhachis of the leaves sometimes aculeate; aculei straight, greyish, up to 8 mm. long. Leaves 4–12 cm. long; rhachis together with the petiole 4–8 cm. long, deeply grooved above; leaflets sessile, opposite or alternate, (2) 3–8-jugate, becoming progressively larger from the basal pair upwards to the apical one; lamina 1·4 × 1–2·3 cm., elliptic to broadly elliptic or obovate, obtuse or rounded or rarely acute at the apex, margin slightly crenulate or serrulate with pellucid glands in the sinuses only, obtuse and usually with small callose auricles at the base, ± asymmetric, the terminal leaflet frequently atrophied or aborted; nerves 4–8 pairs. Inflorescences of terminal panicles, 2–6 cm. long; bracts 0·6 mm. long, ovate, ciliolate. Flowers 4-merous, subsessile or with pedicels up to 1·5 mm. long. Sepals 4, free, 0·5 mm. long, ovate, persistent on the fruit. Petals 4, imbricate, 2·7–3·1 × 1–1·3 mm., narrowly elliptic. Male flowers: stamens 4; vestigial ovary very small. Female flowers: staminodes 4, reduced to the aborted anthers, inserted at the base of a stout gynophore 0·3 mm. long; ovary glabrous, ovoid, conspicuously dotted with glands, 1-locular, 2-ovulate; style c. 0·8 mm. long; stigma discoid, black. Fruit 4–4·5 mm. in diam., subsessile or with a short stipe up to 2 mm. long, subglobose, gland-dotted. Seed black, shiny.