Trees to 30 m tall, 30-70 cm d.b.h., with few aerial roots at base; bark grayish brown; juvenile branches and buds with dense rusty minute pubescence, soon glabrescent; old branches sometimes tubercled, brown. Petioles 2.2-3.5(-4) cm, glabrous; leaf blade oblong-lanceolate or oblong-oblanceolate, (24-)30-38(-45) × 8-14(-18) cm, papery, abaxially with dense rusty minute dendritic hairs, partly glabrescent, adaxially glossy, glabrous, base cuneate to nearly rounded, apex shortly acuminate; lateral veins 20-32 pairs, prominent abaxially, sunken adaxially, tertiary veins obscure. Male inflorescences 2.5-4 cm, with 3-5 flowers, axillary to deciduous leaves, shortly pedunculate, dichotomous or trichotomous, flowers in terminal umbels; peduncle stout, 1.6-1.8 cm, pubescent. Male flowers: pedicel ca. 4 mm; bracteole ovate-elliptic, inserted at base of perianth, tightly enclosing flower; perianth urceolate, 5-6 × 4-5 mm, 3-lobed, lobes triangular-ovate, with dense rusty minute tomentum, darkish purple inside; stamens 7-10; sterile apex of synandrium slightly produced, base of column hairy. Female flowers not known. Infructescences axillary to deciduous leaves; peduncle rather strong, short, densely rusty tomentose, with 1 or 2 fruits; fruiting pedicel ca. 6 × 5 mm. Fruit ellipsoid, 4-5.5 × ca. 3 cm, base with ringlike perianth-scar, 1.5-2.5 mm wide, densely lanose hairy, apex oblique; pericarp 4-5 mm thick when dry. Seeds dark brown when dry, ovoid-ellipsoid, 3.5-4.2 × 2.2-2.4 cm, base subtruncate, apex rounded; aril red. Fl. Sep-Dec, fr. Mar-Jun.

The seeds contain only 6%-7% fat.

Dense forests on mountain slopes or in ravines; 500-600 m. S Yunnan [N Thailand].