Macaranga lowii King ex Hook.f. var. kostermansii Airy Shaw

Small tree up to ca. 15 m tall and 15 cm dbh, reproductive from 5 m tall and 1.5 cm dbh. Twigs solid, glabrous. Stipules needle-like, crowded at twig apex, early-caducous, 2-5 mm long by 0.5-1.5 mm wide. Petioles glabrous, up to ca. 5 cm long. Leaves alternate, ovate to elliptic, 9-23.5 cm long by 2.5-6.5 cm wide, length/width-ratio 3.08-4.7; secondary veins 10-12, not ending in the margin (fading to looping); leaf base usually slightly cordate-auriculate; leaf margin with no or inconspicuous glands; leaf upper surface glabrous, with 2 basal nectaries directly next to petiole insertion; leaf lower surface glabrous, densely gland dotted, with roof-like domatia in axils of secondary veins. Staminate inflorescences not branched; flowers clustered per bracteole; bracteoles with entire margins. Pistillate inflorescences not branched; fruits mm ca. 10 mm wide, 2-locular, with many stiff spines.

Ecology: Collected up to ca. 350 m altitude. A shade tolerant forest understorey tree that can be found in primary as well as dark secondary forest.

Distribution: Endemic for Borneo, where it has been collected in Sabah, West-, Central- and East-Kalimantan.