Dipterocarpus grandiflorus (Blanco) Blanco, Fl. Filip. ed. 2 (1845)

Synonyms
Dipterocarpus blancoi Bl.
Dipterocarpus griffithii Miq.
Dipterocarpus motleyanus Hook.f.
Dipterocarpus pterygocalyx Scheff.
Mocanera grandiflora Blanco
Vatica trigyna Griff.

Diagnostics
Upper canopy tree up to 49 m tall and 67 cm dbh. Stem with resin. Stipules up to ca. 180 mm long. Leaves alternate, simple, penni-veined, glabrous, lamina only slightly folded between secondary veins. Flowers ca. 94 mm in diameter, yellow-pinkish, placed in unbranched inflorescences. Fruits ca. 50 mm long, green-red, with two ca. 140 mm long wings placed on top of the nut, wind dispersed.

Description
Very large hardly buttressed tree. Leaf bud, outside of stipule, parts of petals exposed in bud, ovary apex and sometimes twig densely evenly pale buff pubescent, parts otherwise glabrous. Twigs to 12 mm diameter, stout, becoming grey-brown; internodes short, the leaves clustered around the twig endings. Buds to 2 by 1 cm, ovoid, acute; stipule to 18 by 5 cm, oblong-lanceolate, subacute. Leaves 10-18 by 5-12 cm, ovate, coriaceous, +/- applanate; base obtuse or subcordate; acumen to 1 cm long, short, nerves 15-17 pairs, prominent beneath, spreading; tertiary nerves remotely scalariform, barely elevated; petioles 3-9 cm long, very long, slender. Inflorescences to 18 cm long, very long, slender, axillary, borne in dense groups behind the leaves, unbranched, bearing to 3 remote distichous flowers. Flower buds to 35 by 13 mm, fusiform. Stamens 30, exceeding style at anthesis; filaments broad, compressed, tapering, c. 0.33 the length of the relatively short broadly linear-lanceolate tapering anthers; appendages acicular, c. 0.66 length of anthers. Ovary tapering into the short stoutly columnar style; ovary and style puberulent in the basal half. Fruit pedicel to 2 by 4 mm, stout. Calyx tube to 7 by 3.5 cm. ellipsoid, with 5 pruinose, to 1.5 cm wide, prominent coriaceous wings continuous from base to apex; 2 longer lobes to 22 by 3 cm, oblanceolate-spatulate, obtuse, tapering abruptly to c. 1.3 cm wide at base; 3 shorter lobes to 2 by 1.5 cm, elliptic, subrevolute. [from Flora Malesiana]

Ecology
In undisturbed but also often in disturbed mixed to seasonal dipterocarp forests up to 700 m altitude. Quite often near coastal regions on hillsides and ridges with poor sandy, or ultrabasic soils.

Uses
Timber is commercially harvested. Oil is collected from seeds.

Distribution
Andaman Islands, Thailand, Peninsular Malaysia, Sumatra, Borneo, Philippines.

Local names
Borneo: Bajan, Kalohing, Kangkawang, Kawang, Keruing, Keruing belimbing, Keruing kulup, Keruing simpore, Tempudan, Tempudan tunden.
Malaysia: Keruing belimbing, Keruing pekat, Meluit.
Philippines: Apitong (Tag.).
Sumatra: Keruing, Lagan bras.