Horsfieldia sucosa Warb.

Tree 6-20 m. Twigs 2-10 mm diameter, (whitish) grey-brown or straw-coloured, contrasting with the blackish colour of the dried petioles, early glabrescent, at first with rusty or greyish hairs 0.1-0.3 mm long; bark coarsely striate or not, with a tendency to flake; lenticels conspicuous only on the very young parts. Leaves in 2 or 3 rows, membranous to thin-chartaceous, elliptic-oblong to oblong-(ob)lanceolate, 14-28 by 4.5-8.5 cm, base (long-)attenuate, apex acute-acuminate; upper surface glabrous, drying greenish to blackish brown, lower surface early glabrescent, drying light brown; dots absent, but scattered smaller blackish points often present; midrib ± flat above, glabrous; nerves 13-17 pairs, slender, flat or slightly raised above, lines of interarching indistinct; venation lax, faint; petiole 10-20 by 2-3 mm; leaf bud 10-15 by 2-3 mm, with rusty to greyish brown hairs 0.1-0.3 mm long. Inflorescences behind the leaves, thinly pubescent or late glabrescent, hairs 0.1-0.2 mm long; in male: 3 or 4 times branched, many-flowered, lax or condensed, 7-19 by 5-16 cm, peduncle 1-2 cm long, flowers in clusters of 3-7; in female rather few-flowered, 1-2 cm long; bracts ± ovate-elliptic to lanceolate, acutish, pubescent, 1.5-4 mm long, late caducous; flowers with perianth either mostly 2-lobed (Borneo, see under the subspecies) or mostly 3-lobed (Sumatra, Peninsular Malaysia), glabrous, pedicel slender, usually glabrous (see under subsp. sucosa), articulated, contrasting with the pubescent branches of the inflorescence. Male flowers: pedicel 1-2 mm long; buds (depressed) globose, apex ± flat to broadly rounded, 1.2-1.5 by 1.5-2 mm, cleft 1/3-1/2, when dry not or slightly collapsed at the apex, lobes 0.2-0.3 mm thick; androecium depressed globose, 0.3-0.6 by 0.8-1.2 mm, circular or (in Borneo) broadly ellipsoid in cross section (Plate 2: 42); thecae 14-22, completely sessile with ± incurved apex, column broad, ± saucer-shaped, with broad, flattish, apical hollow to nearly halfway; androphore rather narrow, 0.1-0.3 mm long. Female flowers (subsp. bifissa): pedicel 1-1.5 mm long, when young with minute hairs 0.1 mm long or less towards the base; buds broadly ellipsoid, 2.8-3.5 by 2.2-3 mm, 2-lobed, cleft c. 1/4; ovary 1.5 mm diameter, glabrous, stigma shallowly 2-lobed, 0.1 mm high. Fruits 1-4 per infructescence, broadly ovoid-ellipsoid, apex ± narrowly rounded, 2.3-3.5 by 2-2.5 cm, glabrous, drying blackish, finely granulate, sometimes ± tuberculate; pericarp 4 mm thick; fruiting pedicel 1-2 mm long; perianth in Peninsular Malaysia persistent (see further under the subspecies).

It is a tropical plant. It grows in coastal and mixed forests up to 800 m above sea level. It is often along rivers but can be on hillsides. It grows on sandy and limestone soils.

Can be grown by seedlings.