Mallotus penangensis Műll.Arg.

(Small) trees up to ca. 27 m tall and 40 cm dbh, reproductive from 4 m tall and 5 cm dbh. Twigs solid, glabrous to rarely sparsely hairy (short simple hairs only). Stipules narrowly triangular to triangular, usually early caducous at low altitudes to semi-persistent at higher altitudes, erect, two stipules for each opposite leaf pair, surrounding the twigs completely, 1.5-15 mm long by 0.5-3 mm wide. Petioles glabrous to rarely sparsely hairy, up to ca. 5 cm long. Leaves opposite, one of each pair scale-like (possibly two fused stipules); large leaf elliptic to obovate, 7-29 cm long by 3-12 cm wide, length/width-ratio 1.75-4.31; secondary veins 6-11, not ending in the margin (fading); leaf base obtuse, oblique or not; leaf margin without glands; leaf upper surface glabrous; leaf lower surface glabrous to rarely sparsely hairy, presence of hair tuft domatia in axils of secondary veins increasing with altitude. Staminate inflorescences not branched; one flower per bracteole; bracteoles with entire margins. Pistillate inflorescences not branched, quite often with only terminal fruit developing; fruits 9-15 mm wide, 3-locular, with many long spines.

Ecology: Collected up to ca. 1500 m altitude. A shade-tolerant forest understorey species, usually found in primary forest, but also in closed secondary forests.

Distribution: From Peninsular Thailand to New Guinea. In Borneo collected throughout the island.