Tree 4-20 m. Leaves chartaceous, (elliptic-)oblong, 7-16 by 2.5-6 cm, base attenuate, apex acute-acuminate, upper surface glabrous, drying dull, olivaceous greenish, lower surface bright rusty or chocolate, much contrasting with the upper surface, glabrous; Inflorescences with sparse stellate hairs 0.2-0.3 mm long, ± glabrescent; Fruits 1-4 per infructescence, ellipsoid, 1.8-2.7 by 1.4-1.9 cm, glabrous, drying (dark) brown, hardly lenticellate, pericarp 2-3 mm thick;
Asia-Tropical: Borneo present (Brunei present, Sarawak present)
Malesia: Borneo (Sarawak, Brunei).
Close to H. polyspherula, especially var. polyspherula, with fruits of about the same size. Horsfieldia oligocarpa stands out by the overall pale colour, the pale twigs, the leaves above a dull pale green on drying, contrasting strongly with the bright brown or copper lower leaf surface (more contrasting than usually in H. poly spherula), the small, not many-flowered, ± glabrescent inflorescences, and the markedly coriaceous (? always) flowers.