Dipterocarpus confertus Sloot., Bull. Jard. Bot. Btzg. III, 8 (1927)

Diagnostics
Emergent trees up to 51 m tall and 151 cm dbh. Stems with resin. Stipules ca. 50 mm long. Leaves alternate, simple, penni-veined, peltate, surface folded between secondary veins, densely hairy on lower surface. Flowers ca. 56 mm in diameter, white-pinkish, placed in subcymose inflorescences. Fruits ca. 25 mm long, red-green, with two ca. 130 mm long wings placed on top of the nut, wind dispersed.

Description
Young twig, leaf bud, stipule outside, petiole, nerves and midrib above, nervation beneath, and inflorescence persistently 1.5-3.5 mm long pale fulvous-brown tufted hispid hairy: leaf surface caducously so. Twig 0.8-1 cm apically, stout, uneven, cracked and marked by the thin amplexicaul stipule scars. Bud 1.2-2 by 1-1.7 cm, broadly ovoid, obtuse or subacute. Stipule to 5 cm long and broad, broadly ovate, obtuse, caducous. Leaves (18-)22-35 by (14-)16-22 cm, broadly obovate to orbicular, chartaceous, concave; base obtuse or subpeltate, the lamina continuing as a slight ridge above the base of the midrib; apex obtuse or shortly acuminate; nerves 9-12 pairs, well spaced, at 45 to 60 ; petiole 5-6 cm long. Inflorescence to 7 cm long, subcymose, singly branched or unbranched, short, bearing few distichous flowers; bracts and bracteoles to 25 by 5 mm, linear, obtuse, sparsely tomentose, caducous. Bud to 4 by 1 cm. Calyx and corolla typical, calyx shortly tomentose. Stamens c. 25, as long as style; filaments as long as anther, applanate at base, tapering and filiform below anther; anther narrowly oblong, stout, tapering; appendage almost as long as anther, stout at base, tapering and filiform at apex. Ovary small, ovoid-conical, densely pubescent; stylopodmm indistinct; style 3 times as long as ovary, columnar, slender, tomentose except at apex. Fruit subsessile; calyx tube densely pale fulvous long tomentose, c. 3 by 1.7 cm, narrowly obovoid, with 5 indistinct ridges when mature, tapering basally to the pedicel, only slightly constricted apically; 2 long lobes to 14 by 3 cm, glabrous within, sparsely tomentose outside, oblong-lanceolate, obtuse, tapering to the constricted but non-revolute base, prominently 3-nerved; 3 shorter lobes to 1.7 by 0.7 cm, oblong, recurved distally. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp forests up to 800 m altitude. Mostly on hillsides and ridges with clayey to sandy soils.

Uses
Timber is commercially harvested.

Distribution
Sumatra, Borneo.

Local names
Borneo: Keruing, Keruing buluh, Keruing kobis, Keruing kolong, Keruing eloi, Keruing mengkai, Keruing kerupuk, Tempudau.