Hopea mengerawan Miq., Sum. (1860)

Synonyms
Hancea mengerawan Pierre

Diagnostica
Upper canopy tree up to 44 m tall and 103 cm dbh. Stem with resin. Stipules small, dropped early. Leaves alternate, simple, penni-veined, inconspicuous secondary veins placed close together. Flowers ca. 5 mm in diameter, white-yellowish, placed in panicles. Fruits ca. 10 mm long, green-red, with two ca. 70 mm long wings, wind dispersed.

Description
Tall buttressed tree with dark fissured bark. Twigs, petiole and leaf beneath caducous lepidote, parts otherwise glabrous. Twig c. 2 mm apically, slender; stipule scars short, pale. Leaf bud to 2 by 1 mm, ovoid. Stipule fugaceous. Leaf 6-12 by 2.5-5 cm, lanceolate, thickly coriaceous; base cuneate; acumen to 1.5 cm long, slender but evident beneath, with many short to subequal secondaries; midrib stout, prominent, on both surfaces; petiole 9-11 mm long, relatively short. Panicle to 3 cm long, terminal or axillary, terete, singly branched; branchlets bearing to 6 secund flowers; bracteoles c. 2 mm long, acicular, fugaceous. Flower pale yellow; bud to 3 by 2 mm. ovoid. Calyx lobes ovate, the 2 outer narrower, more coriaceous than the frequently suborbicular 3 inner. Petals sericeous on parts exposed in bud; stamens 15, in 3 unequal verticils; filaments compressed at base, tapering and filiform below the subglobose anthers; appendage to connective slender, 2-3 times length of anther. Ovary ovoid, glabrous; style c. 2 times length of ovary, villous in the basal 5. Fruit pedicel to 2 mm long, slender. 2 longer calyx lobes to 7 by 1.2 cm, narrowly spatulate, narrowly obtuse, c. 3 mm broad above the to 7 by 4 mm narrowly ovate saccate thickened base; 3 shorter lobes to 6 by 5 mm, ovate, acute, saccate. Nut to 10 by 5 mm, narrowly ovoid; style remnant slender. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp forests up to 500 m altitude. Usually on ridges and hillsides with poor sandy to clayey soils, also on ultrabasic.

Uses
The resin and timber are used. The resin was considered one of the best varieties in Sumatra and Malaya.

Distribution
Peninsular Malaysia, Sumatra, Borneo.

Local names
Borneo: Bankirai telor, Bangkirai tembaga, Emang, Emang Jangkar, Luis, Njerakat, Selangan.
Malaysia: Merawan penak, Merawan hitam, Pengerawan, Pengerawan penak.
Sumatra: Merawan banglai, Chengal, Chengal bulu.