Macaranga depressa (Mull.Arg.) Mull.Arg., in DC., Prodr. 15, 2 (1866)

Latin for 'flattened'.

Synonyms
Pachystemon depressus Müll.Arg.
Tanarius depressus (Müll.Arg.) Kuntze

Diagnostics
Shrub up to 10 m tall and 11 cm dbh. Twigs densely hairy. Stipules ca. 12 mm long. Leaves alternate, 3-lobed, peltate, palmately veined, hairy below. Flowers ca. 0.7 mm diameter, green-yellow-reddish, placed in bundles within bracts which are placed in branched inflorescences. Fruits ca. 13 mm diameter, green-yellow, dehiscent, horned capsules, seeds with red aril.

Description
Small tree to 10 m tall, but often smaller or shrub-like; twigs slender, 3-7(-8) mm in diam., solid, not housing ants. Bark smooth, pale grey-brown. Stipules deltate, 6-12 by 5-11 mm, the pair not completely encircling the twig, leathery, not succulent, spreading and usually perpendicular to the twig, usually 4-8 or more pairs present on the shoots. Leaves: petioles terete, slender, 8-20 cm long, not glaucous; blades vary among forms, from very shallowly to deeply tri-lobed. Staminate inflorescences paniculate, erect, to 25 by 10 cm, drying black, to 3 axis orders, main axis flattened, first pair of secondary branches +/- opposite with accessory branches; bracts ovate-elliptic, 5-14 by 4-7 mm, margin entire, apex acute, caducous; flower clusters with 20-40 flowers, spirally arranged and grouped towards the ends of inflorescence branches, mostly much larger than the bracteoles; bracteoles small, broadly ovate, 3-4 by c. 3 mm, only partially enclosing flower clusters, margin entire, apex acute to shortly acuminate. Staminate flowers c. 1 mm long, sessile; sepals fused, splitting irregularly to c. 1/2, apex densely covered in minute red-brown hairs; stamens 1; anthers 3-locular. Pistillate inflorescences paniculate, erect, 4-12 by 4-6 cm, stout, either unbranched or with one pair of short opposite branches without accessory branches, the flowers clustered at ends of the axes; bracts ovate, c. 5 by c. 4 mm, apex acute to acuminate, caducous. Pistillate flowers 3-5 mm long, solitary in bract axils; calyx urceolate, 1-2 mm long, densely ferrugineus pubescent, with scattered yellow granular glands towards the apex, persistent, splitting irregularly as ovary expands; ovary 4-5- carpellate, c. 1.5 mm long; styles 2-3 mm long, with long and finely acuminate apices, expanding as fruit matures, fused at base, free and spreading from c. 1/3 of the length, persisting to form a prominent 3-5 mm long crown at fruit apex; stigma not dissected. Fruits subglobose, compressed, 6-8 by 8-11 mm, sessile, one discrete glandular patch on each carpel wall developing into a long slender horn-like process 3-7 mm long, covered in yellow, sticky exudate, glabrous or rarely with some scattered ferrugineus hairs towards the base and on the sutures. Seeds subtriangular-ovoid, c. 4 mm diameter, black, with shallow coarse grooves and a small cruciform scar at the columella attachment point, completely encased in a fleshy bright red aril. [from Flora Malesiana]

Ecology
In open or disturbed sites in mixed dipterocarp, swamp and sub-montane forests up to 1700 m altitude, but most common in secondary forests and scrub vegetations. Usually along rivers and in alluvial sites, but also common along roads and forest edges, hillsides and ridges. Also found on limestone.

Distribution
Sumatra, Borneo.

Local names
Borneo: Binuah, Mahang, Penuang, Sedaman jari.