Aporosa grandistipula Merr., Philip. J. Sci. 21 (1922)

Latin for 'with large stipules'.

Diagnostics
Understorey tree up to 14(-20) m tall and 20 cm dbh. Stipules ca. 18 mm long, curved. Leaves alternate, simple, penni-veined, glabrous, sometimes margin slightly toothed. Flowers ca. 0.3 mm in diameter, green-yellow, placed in racemes. Fruits ca. 12 mm long, yellow-orange-red, dehiscent capsule, seeds with orange aril.

Description
Tree, up to 20 m high, up to 18(-20) cm diameter. Bark (dark to pale) greyish or brownish, reddish, chocolate, or red-brown, smooth, c. 1.5 mm thick; inner bark brown(ish), greenish, reddish, pink, or yellowish. Wood (pale) brownish, reddish, or yellowish to white. Young branches sparsely puberulous. Stipules falcate, 6-14 by 12-24 mm, often persistent, glabrous, often black disc-like glands along margin beneath. Petiole terete, adaxially or around grooved, 8-47 by 1-2 mm, sparsely puberulous, lower pulvinus 1.5-4 by 1.5-3 mm, upper pulvinus 3-9 by 1.5-3 mm, both distinct. Leaves narrowly elliptic to narrowly obovate, 12-35 by 3.5-10.5 cm; base emarginate to truncate, basal glands absent; margin lowly glandular-crenate to lowly glandular-serrate, marginal glands many, small, black, distinct; apex acuminate to cuspidate; blade thinnish, smooth, dull, not brittle, drying greenish greyish to greyish blue above, (dark) brown-grey beneath, glabrous above, only midrib and nerves sparsely puberulous beneath, glabrescent; dots irregularly laxly set, fine, greyish black, fading; disc-like glands few, small, indistinct, along the margin. Nervation: midrib (slightly) prominent above, prominent beneath; nerves 14-23 pairs, slightly prominent to flat above, prominent beneath, marginal arches distinct, 2-4 mm from the margin; tertiary veins and venation distinct, rather densely reticulate, slightly scalariform, slightly prominent to flat above, (slightly) prominent beneath. Inflorescences axillary or just below the leaves. Staminate inflorescences 3-6 clustered together, 13-61 by 0.3-0.5 mm, subglabrous; peduncle 1-3 by 0.3-0.5 mm; bracts broadly triangular, inconspicuous, 0.8-1.2 mm long, glabrous, margin sparsely ciliate; glomerules globose, 0.8-1.5 by 0.8-1.5 mm, consisting of 7-12 densely set flowers, spaced at 1.5-6 mm along the rachis; pedicel minute. Staminate flowers 0.5-1 mm long; sepals 4 (or 5), (narrowly) obovate, subequal, 0.5-0.8 mm long, connate at base, glabrous, margin sparsely ciliate; stamens 3 (or 4), 0.5-0.9 mm long, slightly exserted; anthers 0.2-0.3 mm long, connective glabrous; pistillode minute, lumpy. Pistillate inflorescences 1-3 clustered together, 13-24 by 0.5-0.8 mm, subglabrous; flowers up to 11, laxly arranged along the rachis; bracts broadly triangular, 0.3-0.5 mm long, glabrous, margin sparsely ciliate; bracteoles triangular, 0.2-0.3 mm long, glabrous, margin ciliate; pedicel 3-5 mm long, sparsely puberulous. Pistillate flowers 2.5-4 mm long; sepals 5, ovate, subequal, patent, 0.6-1.2 mm long, thin, glabrous, margin sparsely ciliate; ovary ovoid, 2-3 mm long, 3-locular, smooth, glabrous; stigmas slightly raised, elongated, apically bifid to near base, perpendicular to the sides of the ovary, recurved, 1-1.5 mm long, laxly papillate above, glabrous, slightly ribbed to smooth beneath, glabrous, style remnant absent. Infructescences 10-41 by 0.8-1.2 mm, glabrous; fruiting pedicel 4-9 mm long, glabrous. Fruits ovoid, not stiped, not beaked, 11-16 by 10-14 mm, punctate, young ones slightly ridged on sutures, drying (dark) brown, glabrous; pericarp 0.5-1 mm thick, slightly fleshy; septae and column glabrous. Seeds 2 or 3, half-terete, ovoid, 7-11 by 6.5-9 by 3-4 mm. [from Flora Malesiana: http://www.nationaalherbarium.nl/Euphorbs/specA/AporosaT.htm]

Ecology
Primary, (old) secondary, disturbed, logged, alluvial, or riverine forest; in flat, low undulating, hilly, moist, or swampy country, sometimes subject to flooding; on ridges, hills, or along streams. Soil: sandy, clayey, clay-loam, sandstone, limestone, rich yellow to blackish, stony. Altitude: 5-500 m.

Uses
Fruits are edible.

Distribution
Borneo.

Local names
Borneo: Boata, Bua bae, Galang-galang, Kayu massam, Ketune, Mantus, Ulas.