Aporosa nitida Merr., Pl. Elmer (1929)

Latin for 'shiny'.

Diagnostics
Sub-canopy tree up to 25 m tall and 30 cm dbh. Stipules dropped early. Leaves alternate, simple, penni-veined, large, glabrous. Flowers ca. 0.3 mm in diameter, yellow, placed on club-shaped inflorescence. Fruits ca. 20 mm long, yellow-orange, dehiscent capsule, seeds with orange aril.

Description
Shrub or tree, up to 25 m high, up to 30 cm diameter. Bark black, (dark) brown to (patchy) greyish, greenish, yellowish, or whitish, smooth or lenticellate; inner bark (pale) brownish, pale greenish, or (pale) yellowish to greyish white. Wood yellow to white. Twigs brown, young ones green, glabrous. Stipules not seen, early caducous. Petiole terete, adaxially lowly grooved, 13-36 by 1.5-2.5 mm, glabrous, lower pulvinus 3-6 by 2-3 mm, upper pulvinus 8-12 by 2.5-3.5 mm, both distinct. Leaves narrowly ovate to narrowly elliptic, 15-32.5 by 5-13 cm; base obtuse to acute, basal glands absent; margin lowly undulate to lowly glandular-crenate, marginal glands regular, distinct, brownish to black; apex acuminate to cuspidate; blade thick, young leaves lowly white granular on nerves, shiny, not brittle, drying greyish green or yellowish green above and beneath, glabrous; dots laxly set, fine, greyish, fading; disc-like glands minute, brownish, occasionally scattered along the margin and at base within marginal arches, often indistinct. Nervation: midrib prominent to flat above, prominent beneath; nerves 9-13 pairs, prominent to flat above, sometimes slightly sunken, prominent beneath, marginal arches distinct, 3-5 mm from the margin; tertiary veins and venation fading, rather densely reticulate, slightly prominent to flat. Inflorescences axillary or just below the leaves. Staminate inflorescences 2-5 clustered together, 12-36 by 3-8 mm, subglabrous; peduncle 2-24 by 0.7-1 mm; bracts broadly triangular, inconspicuous, 0.3-0.5 mm long, biglandular, glabrous, margin ciliate; glomerules ellipsoid, 2-3 by c. 1.5 mm, consisting of 9-13 densely set flowers, sometimes spaced at 0.5-1.5 mm at base of rachis, densely massed apically; pedicel c. 0.2 mm. Staminate flowers 0.3-0.7 mm long; sepals 4, narrowly obovate, 0.2-0.5 mm long, connate at base, sparsely hairy outside, glabrous inside; stamens 2, slightly exserted, 0.3-0.7 mm long; anthers 0.1-0.2 mm long, connective glabrous; pistillode absent. Pistillate inflorescences 2 or 3 clustered together, 2-4 by 0.8-1 mm, subglabrous; flowers single at apical end of rachis; bracts broadly triangular, 0.3-0.5 mm long, fleshy, glabrous outside, hairy at base only inside; bracteoles as bracts; pedicel 1.5-5 mm long, sparsely puberulous. Pistillate flowers 3-3.5 mm long; sepals 5 or 6, subequal, ovate, reflexed, 0.5-0.8 mm long, fleshy, glabrous, margin ciliate; ovary ellipsoid, 2-3 mm long, 4-6(-7)-locular, smooth, glabrous; stigmas sessile, broad, flattened on top of the ovary, straight, almost completely divided, 0.5-1 mm long, smooth to slightly ribbed above, glabrous, connate to the ovary beneath. Infructescences 9-12 by 1.2-2 mm, sparsely tomentose, glabrescent; fruiting pedicel 3-9 mm long, sparsely puberulous. Fruits globose, not stiped, not beaked, 21-28 by 22-27 mm, but recorded up to 27-30 mm diam. when fresh, smooth, drying light yellow to orange brown, glabrous; pericarp 3-5 mm thick, fleshy; septae and column glabrous. Seeds 3-6, half-terete, ellipsoid, 9-11 by 5-8 by 4-5 mm. [from Flora Malesiana: http://www.nationaalherbarium.nl/Euphorbs/specA/AporosaT.htm]

Ecology
Primary, secondary, riverine, or recently logged over forest; on hill sides, hill tops, ridges, road sides, and along river banks or swamps; in low or undulating country, rolling land, marshy or moist areas, or alluvial. Soil: clay, sandstone, sandy clay loam, loam with lime, silty clay, laterite, or stony, granodiorite derived, yellowish to reddish. Altitude: low to 1000 m.

Uses
Fruits are edible.

Distribution
Borneo.

Local names
Borneo Bilung, Janggau, Janggau daun besar man, Kayu besi, Mata rusa, Punu-punu, Susu diangas.