Macaranga rostrata Heine, Repert. Spec. Nov. Regni Veg. 54: 233 (1951)

Name meaning 'beaked'.


Small trees up to ca. 20 m tall and 30 cm dbh, reproductive from 7 m tall and 4 cm dbh. Twigs solid, glabrous to hairy. Stipules ovate, semi-persistent, erect to spreading, not surrounding the twigs completely, 6-10 mm long by 3-5 mm wide. Petioles glabrous to hairy, up to ca. 12 cm long. Leaves alternate, ovate, peltate or not, 9-18 cm long by 4.5-11 cm wide, length/width-ratio 1.18-2.07; secondary veins 8-10, usually ending in the margin, sometimes looping; leaf base rounded to cordate (also when peltate), peltate margin length (when present) 0.1-1.2 cm; leaf margin with conspicuous glands; leaf upper surface glabrous, with 2-6 basal nectary glands on basal veins, some distance from petiole insertion; leaf lower surface hairy, not or only sparsely gland dotted. Staminate inflorescences branched; flowers clustered per bracteole; bracteoles with entire margins. Pistillate inflorescences branched; fruits 9-10 mm wide, 4(-5)-locular, one glandular patch on each carpel wall developing into very long horn-like appendages.

Submontane tree to 20 m tall; twigs slender, 3-5 mm in diam., terete, glabrous or finely pubescent with short silvery hairs, not glaucous, solid, not housing ants. Stipules ovate-elliptic, 5-10 by 3-5 mm, erect and spreading from the twig and sometimes slightly recurved when dry, abaxial surface finely pubescent along the midrib and towards the base, adaxial surface mostly glabrous, the pair not completely encircling the twig, leathery but not succulent, 1-4 pairs present on shoots. Leaves: petioles terete, 3-12 cm long, finely pubescent with short silvery or golden hairs, rarely almost glabrous; blades ovate-elliptic, broadest near the base, 9-20 by 4-10(-12) cm, not or only shallowly peltate with the petiole insertion less than 15 mm from the basal leaf margin, base rounded or slightly cordate when not peltate, margin entire to almost wavy or serrate, apix acute to narrowly acuminate, adaxial surface glabrous or rarely with minute scattered hairs along the veins and with 2-4 round or oval c. 1 mm diameter flat nectaries adjacent to the basal leaf margin near the petiole insertion, abaxial surface densely pubescent along all veins or rarely sparsely pubescent, not glaucous; 1st degree venation palmate with 5-7 prominent veins, 2nd degree veins scalariform looping near the leaf margins and terminating in small protruding flattened nectaries, 3rd degree veins scalariform; young leaves red-brown, densely pubescent along the veins, the very youngest leaf bud densely covered in erect pointed silvery or golden hairs. Staminate inflorescences slender, green when fresh, drying blackish, paniculate, erect, 4-15 by 1-6 cm, glabrous or sometimes scattered with silvery hairs on the basal axes and minute ferrugineus hairs on the distal axes, to 3(-4) axis orders, main basal axis short, flattened, first pair of secondary branches +/- opposite and usually with accessory branches; bracts elliptic, 5-12 by 3-6 mm, margin entire, apex acute, mostly glabrous or margin and adaxial surface scattered with minute ferrugineus hairs, caducous; flower clusters with 15-25 flowers, spirally arranged and evenly spaced; bracteoles broadly rounded, 2-4 by 3-5 mm, cupulate, enclosing flower clusters, margin entire, apex shortly acute, adaxial surface densely covered with minute ferrugineus hairs particularly towards the base, abaxial surface scattered with ferrugineus hairs and yellow granular glands. Staminate flowers c. 1 mm long, sessile; sepals fused, splitting to c. 1/5, apex densely covered in minute red-brown hairs; stamens 1; anthers 3-locular. Pistillate inflorescences erect, shortly paniculate, 3-7 by 1-3 cm, stout, 1-2 axis orders, secondary branches +/- opposite, green when fresh and drying black, mostly glabrous but main basal axis usually with scattered erect silvery hairs; bracts caducous, not seen. Pistillate flowers 5-6 mm long, solitary; calyx c. 3 mm long, urceolate, glabrous, persistent, splitting irregularly as ovary expands; ovary 4(-5)-carpellate, 3-4 mm long; styles 2-3 mm long, fused at base, free and spreading from c. 1/3 of length, persisting to form a prominent 3-4 mm long crown at fruit apex; stigma not dissected. Fruits subglobose, 6-8 (excluding horns) by 9-10 mm, sessile, one discrete glandular patch on each carpel wall developing into a very long and slender horn-like process 7-15 mm long, covered in sticky yellow-green exudate. Seeds subtriangular-ovoid, c. 4 mm in diam., black, with shallow coarse grooves and a small cruciform scar, encased in a fleshy aril, aril color not seen. [from Flora Malesiana]

Usually in gaps or along forest edges up to an elevation of 2300 m.


Local names