Macaranga winkleri Pax & K.Hoffm., in Engl. Pflanz. 7 (1914)

Named after H. Winkler [1875-?], a German Botanist.

Diagnostics
Understorey tree up to 20 m tall and 31 cm dbh. Twigs hollow, ant-inhabited, glabrous. Stipules erect, ca. 21 mm long. Leaves alternate, simple, peltate, palmately-veined, glabrous. Flowers ca. 0.5 mm diameter, green-yellow-reddish, placed in bundles within bracts which are part of large panicles. Fruits ca. 3 mm diameter, greenish, 2-lobed, dehiscent capsules.

Description
Slender tree to 22 m tall, though often flowering from c. 5 m. Bark smooth, remaining green at maturity, often with prominent ant holes. Twigs glabrous, hollow, 7-14 mm diam., housing ants, with prominent ant holes often in narrow grooves. Stipules narrowly ovate, 15-25 by 8-13 mm, with a long finely acuminate apex, glabrous, coriaceous, not succulent, recurved with the lateral sides appressed and appearing horn-like, producing food-bodies on the abaxial surface, numerous pairs present on the shoots, the pair not completely encircling the twig. Leaves: petioles terete, 16-35 cm long, slender, glabrous; blades ovate, 16-40 by 12-25 cm, base rounded, 3-8 cm peltate, margin entire, with small protruding conical glands, leaf apex acute to finely acuminate; adaxial and abaxial surfaces entirely glabrous, not glaucous, patellar glands absent from lamina; 1st degree venation palmate, with (5-)6-7(-8) prominent veins, 2nd degree venation looping just inside the leaf margins, 3rd degree venation scalariform, 4th degree venation weakly scalariform; leaf margin entire; young leaves glabrous, characeous, abaxial surface densely punctate glandular. Staminate inflorescences paniculate, erect, 20-35 by 12-20 cm, glabrous, 4 axis orders, main axis terete or slightly angular when dry, first pair of secondary branches alternate without accessory branches; bracts narrowly ovate, 10-25 by c. 6 mm, apex acute, persistent, base often slightly cordate, margin entire, glabrous, usually reddish; flower clusters with 6-15 flowers, spirally arranged, evenly spaced forming catkin-like clusters on the ultimate inflorescence branches; bracteoles ovate, 2-5 by 1.5-4 mm, saccate, enclosing flower clusters, apex rounded, margin deeply dissected into 4-8 slender 2-3 mm long tentacular lobes with small conical apical glands at apices, abaxial surface with several subprominent ribs and scattered to densely covered with yellow granular glands, otherwise glabrous, adaxial surface densely ferruginous pubescent particularly towards the base. Staminate flowers c. 1 mm long, shortly pedicellate; sepals free, apex with scattered yellow glands, glabrous or with a few ferruginous hairs at base; stamens 2-3; anthers 4-locular. Pistillate inflorescences paniculate, erect, 10-26 by 8-15 cm, glabrous, to 3 axis orders, secondary branches alternate, glabrous or with scattered minute ferruginous hairs towards apices; bracts ovate, c. 1 cm long, often slightly cordate, usually persistent; bracteoles ovate, c. 3 by 2 mm, with 3-6 short narrow gland-tipped lobes, abaxial surface densely yellow glandular, adaxial surface densely ferruginous pubescent. Pistillate flowers 1-3 mm long, 2-5 in bract axils, pedicellate; calyx urceolate, c. 1 mm long, with minute yellow granular glands, glabrous, persistent and spreading at base of fruit; ovary 2-carpellate, c. 1 mm long; styles short and thick, c. 0.8 mm long, broad, free, persistent; stigma not dissected. Fruits 2-2.5 by 3-4 mm, bilocular, locules globose, pedicellate, carpel walls with 4-8 minute knob-like caducous processes, evenly covered in yellow granular glands, sticky; pedicel 3-7 mm long, slender, with yellow granular glands, glabrous. Seeds c. 1.5 mm diam., ovoid, black, very coarsely verrucose, with a small cruciform scar, encased in a fleshy violet aril. [from Flora Malesiana]

Ecology
In open sites (usually riversides) in mixed dipterocarp and sub-montane forests up to 1800 m altitude. Often common in disturbed forests, especially along roadsides and other open places on hillsides. Often on clay to rocky soils.

Distribution
Borneo.

Local names
Borneo: Benuak kubong, Purang, Sedamai, Tisit.