Dipterocarpus geniculatus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Dipterocarpus geniculatus Vesque

Protologue: Compt. Rend. Hebd. Séances Acad. Sc. 78: 626 (1874).

Vernacular names

• Brunei: keruing kerubong, keruing guntang, keruing belimbing
• Malaysia: keruing kerubong (Sarawak), keruing tangkai panjang (Sabah).

Distribution

Borneo.

Uses

D. geniculatus is locally an important source of keruing.

Observations

• A large to very large tree of up to 60 m tall, bole tall, cylindrical, up to 200 cm in diameter, buttresses low and broadly rounded, sometimes continuing as ridges up to 2 m tall, bark surface pale or dark blackish-brown, very flaky, outer bark brown, inner bark reddish-brown, sapwood yellowish, inside pinkish-ochre, heartwood reddish-brown; buds broadly ovoid, pale cream tomentose.
• Leaves elliptical to obovate, 7-12 cm × 5-7 cm (subsp. geniculatus) or 20-35 cm × 12-16 cm (subsp. grandis), base obtuse, apex obtuse or shortly acuminate, secondary veins 10-12 pairs, beneath sparsely pubescent to glabrescent, petiole 3-10 cm long, stipules broadly lanceolate, acute, shortly pale cream tomentose.
• Stamens 30.
• Fruit calyx tube obovoid, shortly densely persistently pubescent, 5-ridged, 2 larger fruit calyx lobes up to 12 cm × 2.5 cm (subsp. geniculatus) or 15 cm × 4 cm (subsp. grandis), 3 shorter ones about 1 cm × 1.5 cm.

D. geniculatus is divided into two subspecies: subsp. geniculatus and subsp. grandis P. Ashton. It occurs on leached clay soils in lowland dipterocarp forest up to 400 m altitude. The density of the wood is 730-760 kg/m³at 15% moisture content.

Selected sources

30, 31, 89, 258, 476, 748.

Main genus page

• Dipterocarpus (Timbers)

Authors

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