Hopea dryobalanoides Miq., Sum. (1860)

Synonyms
Hancea dryobalanoides Pierre
Hopea borneensis Heim
Hopea micrantha (non Hook.f.) King
Hopea sarawakensis Heim

Diagnostics
Emergent tree up to 61 m tall and 111 cm dbh. Stem with resin. Stipules up to ca. 2 mm long. Leaves alternate, simple, penni-veined, secondary veins inconspicuous, placed close together. Flowers ca. 5 mm in diameter, white-yellow-pinkish, placed in short panicles. Fruits ca. 10 mm long, green-red, with two ca. 65 mm long wings, wind dispersed.

Description
Tall tree with flaky bark and prominent thin buttresses and a few stilt roots. Young twig, leaf bud, petiole and leaf beneath shortly densely greyish brown fugaceous pubescent; domatia persistently so. Twig to 1 mm diameter apically, terete, slender, glabrous, smooth. Leaf bud to 1 mm long, minute. Stipule to 2 mm long, fugaceous. Leaves 5-12 by 1.5-4.5 cm, ovate-lanceolate, thinly coriaceous; base cuneate, equal or subequal; acumen to 2 cm long, narrow, caudate; nerves 8-12 pairs, slender but distinct beneath, curved, with or without scattered axillary domatia; with few short secondaries; midrib slender, raised and frequently sharp on both surfaces, more prominently so beneath; petiole 5-10 mm long, short, slender. Panicle to 5 cm long, terminal or axillary. 1-2- axillary, lax. terete, puberulent to glabrous; singly branched, branchlets bearing to 6 flowers; bracteoles small, linear. Bud small, broadly ovoid. Calyx puberulent outside, fimbriate; 2 outer lobes ovate, acuminate; 3 inner lobes suborbicular, shortly mucronate. Petals narrowly lanceolate, shortly tomentose on parts exposed in bud, pale yellow. Stamens 15, in 3 whorls; filaments slender, tapering; anthers subglobose; appendage to connective c. 2 times length of anther, sometimes sparsely glandular papillose. Ovary ovoid, glabrous, without distinct stylopodium; style as long as ovary setose in the basal half, glabrous distally. Fruit calyx glabrous; 2 longer lobes to 6.5 by 1.5 cm. long, spatulate. subacute, pronouncedly twisted, tapering to 5 mm broad above the to 6 by 6 mm deltoid thickened saccate base; 3 shorter lobes to 8 by 6 mm, shorter than the nut, broadly ovate, obtuse or subacute, saccate but thinner than base of outer lobes. Nut to 10 by 8 mm, broadly ovoid, glabrous; style remnant to 1.5 mm long, filiform. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp forests up to 600 m altitude. Mostly on hillsides and ridges, but also on alluvial sites. Usually on clay soils, but also growing on sand. Widespread, locally frequent, clay-rich fertile soils on undulating or well drained flat land, or ridges; common on basalt and intermediate igneous and volcanic rocks on slopes and ridges.

Uses
Timber and resin are used. Formerly an important producer of damar mata kuching.

Distribution
Peninsular Malaysia, Sumatra, Borneo, Philippines.

Local names
Borneo: Berjankar, Luis, Mang besi, Mensega, Selangan, Selangan batu, Selangan penak.
Malaysia: Mata kuching hitam, Merawan mata kuching.
Sumatra: Damar mata kuching, Bayang gunong, Seluai hitam.