Dipterocarpus cornutus Dyer, Fl. Br. Ind. 1 (1874)

Synonyms
Parinari dillenifolia R.Br. ex Wall. [Invalid]

Diagnostics
Upper canopy tree up to 50 m tall and 89 cm dbh. Stem with resin. Stipules up to ca. 200 mm long. Leaves alternate, simple, penni-veined, surface folded between secondary veins, lower surface glabrous, conspicuously lighter than upper surface. Flowers ca. 40 mm in diameter, white-yellow, placed in unbranched compressed inflorescences. Fruits ca. 20 mm long, green-red, with two ca. 140 mm long wings placed on top of the nut, wind dispersed.

Description
Large pale-barked tree. Twigs, leaf buds, stipule outside, petiole, leaf beneath including nervation, midrib above, calyx, corolla outside and ovary apex densely persistently pale ocherous-cream puberulent, sometimes fulvous on twigs; fruit calyx glabrescent: leaf bud, stipule and base of inflorescence frequently also densely +/- caducously long rufous tufted tomentose, the short even indumentum persisting after the tufts drop. Twig c. 10 by 8 mm, stout, somewhat compressed, pale brown, sometimes becoming papery flaky. Bud lo 6 by 1 cm, lanceolate, acute; stipule to 20 by 4 cm, lorate, narrowly obtuse. Leaves 15-30 by 7.5-18 cm, broadly elliptic to oblong-ovate, thickly coriaceous, cream beneath, prominently persistently plicate; base obtuse; apex obtuse or subretuse; nerves 18-21 pairs, prominent beneath; tertiary nerves very slender, hardly elevated, densely scalariform; petiole 5-8.5 cm long, c. 4mm diameter, long, stout. Inflorescences to 28 cm long, to 5 by 3 mm at base, axillary, somewhat compressed, unbranched, bearing to 10 distichous flowers. Flower bud to 3.5 by 1 cm, fusiform. Stamens 30, exceeding style at anthesis; filaments short, broad, applanate, deltoid; anthers c. 5 times length of filaments, broadly linear-lanceolate, tapering; appendage stoutly acicular, tapering, c. 3 length of anther. Ovary ovoid, small, densely hirsute as also the basal half of the stoutly columnar +/- capitate style. Fruit shortly pedicellate to subsessile; calyx tube to 2.5 cm long, to 3.7 cm including the 5 prominent distal tubercles, subglobose, densely verrucose lenticellate; 2 longer lobes to 21 by 5 cm, oblong, narrowly obtuse, abruptly constricted to c. 2 cm wide and revolute at base; 3 shorter lobes to 15 by 15 cm. suborbicular, revolute. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp forests up to 1000 m altitude. Mostly on ridges with well drained sandy soils.

Uses
Timber is commercially harvested.

Distribution
Peninsular Malaysia, Sumatra, Borneo.

Local names
Borneo: Apot, Kapenkaluang, Karang, Keruwing, Keruing, Kruing, Tampudan, Tampudau, Tampurau, Tempudan laki.
Peninsular Malaysia: Keruing gombang, Keruing dadek, Keruing (mara)keluwang, Keruing chaier, Keruing babi.