Hydnocarpus borneensis Sleum., Bot. Jahrb. 69 (1938)

Diagnostics
Understorey tree up to 17 m tall and 19 cm dbh. Stipules ca. 7 mm long. Leaves alternate, simple, penni-veined, glabrous, base asymmetrical, secondary veins conspicuously looping near margin. Flowers ca. 30 mm diameter, green-white-yellow, placed in short cymes or bundles. Fruits ca. 70 mm diameter, yellow-orange-brown, fleshy berries/capsules.

Description
Tree, (4-)10-18(-30) m; young branchlets initially covered with rusty, fascicled and simple hairs, soon glabrescent. Leaves oblong to broadly oblong, +/- abruptly acuminate, mostly inequilateral at the base, subcoriaceous, first laxly fasciculate-pilose on midrib and nerves, specially beneath, later glabrous, shining and olivaceous or brown above when dry, dull red-brown beneath, 15-30 by 6-9 cm; midrib little prominent above, manifestly so beneath, nerves mostly a little impressed above, very prominent beneath, reticulations distinct only beneath; petiole 1-1.5 cm. Stipules ovate-lanceolate, 7 by 2 mm, pubescent, rather early caducous. Cymes rusty-tomentose all over, reduced to (2-)3 or 4 'white and yellow' or greenish-white, fragrant flowers; peduncle 3-6 mm only, stout. Pedicels of the male flowers rather slender 1.5-2 cm, those of the female ones shorter and stouter, c. 5 by 2 mm. Sepals ovate, 10-12 by 6 mm, finely and densely ferrugineous-tomentose outside, greyish-pubescent inside. Petals white to yellowish, oblong, rather dark-purple when dry, glabrous, involute, 12-15 by 4 mm; scales lanceolate, 10 by 2 mm, pilose towards the apex, male Flowers: filaments thick, elongate-triangular, 5 mm; anthers oblong-subsagittate, 5 mm. Rudiment of ovary hirsute. Female Flowers: filaments deltoid, 1.5 mm, fleshy; anthers 0. Ovary elongate-ovoid, yellowish tomentose, cylindrically contracted towards the apex; stigma nearly peltate, lobes very short. Fruit depressed-ovoid or bottle-shaped, contracted at the apex or apiculate, fulvous-tomentose, 6-8 by c. 4 cm when fully developed, upper attenuate part 1-1.5 cm long; pericarp thin. Seeds 8-10, c. 2 cm across. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp and swamp forests up to 600 m altitude. Often on alluvial places and riversides, but also common on hillsides and ridges. On sandy to clay soils.

Distribution
Borneo.

Local names
Indonesia: Andara, Empupuak, Madansat, Nangka-nangka, Pasir-pasir, Senumpel, Tulang asai.