Dipterocarpus costulatus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Dipterocarpus costulatus v. Slooten

Protologue: Bull. Jard. Bot. Buitenzorg, sér. 3, 8: 315, f. 7 (1927).

Vernacular names

• Brunei: keruing kipas
• Indonesia: keruing bajan (Sumatra, Kalimantan), keruing ladan, kyakat (West Kalimantan)
• Malaysia: keruing kipas (general), keruing marah keluang (Peninsular), kerubang (Sabah).

Distribution

Peninsular Malaysia, Sumatra and Borneo.

Uses

D. costulatus is an important source of keruing.

Observations

• A large tree of up to 50 m tall, bole branchless for up to 35 m, up to 127 cm in diameter, buttresses rounded, up to 1.5 m tall, up to 1 m long, stout, bark surface grey or pale greenish-cream, uneven, but overall smooth, outer bark brown, inner bark dark pinkish ochre-brown to lighter ochre, sapwood light yellow-ochre, heartwood ochre-brown; buds falcate, glabrous and frequently pruinose.
• Leaves broadly elliptical to ovate, 12-20 cm × 7-14 cm, base prominently cuneate, apex obtuse to shortly acuminate, persistently folded between the 11-14 pairs of secondary veins, glabrous, petiole 3-6 cm long, stipules lorate, subacute, shortly buff pubescent outside.
• Stamens 24.
• Fruit calyx tube glabrous, subglobose, with 5 prominent flange-like tubercles, 2 larger fruit calyx lobes up to 20 cm × 4 cm, 3 shorter ones up to 7 mm × 6 mm.

D. costulatus occurs locally, on poor, often sandy soils on flat and undulating or sometimes periodically inundated land up to 600 m altitude. The density of the wood is 800-980 kg/m³at 15% moisture content.

Selected sources

31, 258, 476, 514, 677, 737, 748.

Main genus page

• Dipterocarpus (Timbers)

Authors

• T. Smitinand (selection of species),
• C. Phengklai (selection of species),
• L.E. Groen (selection of species)