Knema riangensis W.j.de Wilde

Tree 3-12 m. Twigs subterete or ± angular, 1.5-3(-4) mm diameter, with minute dull brown hairs 0.1 mm long, glabrescent; bark coarsely striate, not flaking. Leaves membranous, elliptic-oblong to oblong-lanceolate, 14-30 by 5-10.5 cm, base short-attenuate or rounded, apex acute-acuminate; drying olivaceous above, paler, with (sub)persistent dense pale yellowish to greyish almost uniform hairs 0.1 (-0.2) mm long beneath; dots absent; midrib raised above; nerves 15-23 pairs, ± flat to raised above, venation distinct; petiole 10-20 by 2-4 mm, late glabrescent. Inflorescences: peduncle to 1 mm long, bra-chyblast wart-like, simple, or forked, to 5 mm long; in male 2-6-flowered, female 2-4-flowered; flowers with dull brown hairs 0.1 (-0.2) mm; perianth 3-lobed, reddish inside. Male flowers: pedicel 3-4 mm long, bracteole persistent, 0.5 mm long, 0.5-1 mm below the apex; buds broadly obovoid, 2 by 1.7 mm, cleft 5/6, lobes 0.5 mm thick; staminal disc circular or subtriangular, flat, 0.8-1 mm diameter, anthers 9, sessile, suberect, 0.3 mm long, closely set; androphore tapering (obconical), 0.8 mm long, sometimes with few minute hairs at base. Female flowers: rather stout, pedicel 5-12 mm long, bracteole slightly above median; buds ± obovoid, 4-5 by 3 mm (or 7 by 4 mm, see note 2), cleft c. 1/2, lobes 0.5-1 mm thick; ovary ovoid, 2-4 mm long, with dense hairs 0.1 (-0.2) mm long; style broad, 0.5 mm long, stigma lobes 2, each coarsely 2-4-lobulate. Fruits 1 or 2 per infructescence, ellipsoid, 2.4-4 by 1.7-2.5 cm, with persistent rust-brown hairs 0.1 mm long, dry pericarp 1-2 mm thick; fruiting pedicel 8-12 mm.

It is a tropical plant. It grows in primary forest and along rivers. It is often on yellow sandy clay. It grows between 100-600 m altitude.

The aril or fleshy layer around the seeds in bright red and edible.