Macaranga spathicalyx Whitmore

Diagnostic characters: Small trees up to ca. 18 m tall and 17 cm dbh, reproductive from 13 m tall and 10 cm dbh. Twigs solid, glabrous. Stipules ovate, early-caducous to semi-persistent, erect, not surrounding the twigs completely, 4-7 mm long by 3-5 mm wide. Petioles glabrous, up to ca. 13 cm long. Leaves alternate, ovate, peltate, 12.5-14 cm long by 7-10,5 cm wide, length/width-ratio 1.19-2; secondary veins 11-12, ending in the margin; leaf base broadly rounded, peltate margin length 0.4-0.8 cm; leaf margin with inconspicuous glands; leaf upper surface glabrous, without or with 1-4 basal nectary glands on basal veins directly under petiole insertion; leaf lower surface glabrous, densely gland dotted. Staminate inflorescences unknown (possibly similar to Macaranga costulata). Pistillate inflorescences branched; fruits 3-4 mm wide, subtended by enlarged, spath-like calyx lobe, 2-locular, with spines, whole fruit covered by glands.

Ecology: Collected between 1600 and 1800 m altitude. In primary and secondary forests.

Distribution: Endemic for Borneo, where it has been collected in Sabah only.