Dipterocarpus conformis (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Dipterocarpus conformis v. Slooten

Protologue: Bull. Bot. Gard. Buitenzorg, ser. 3, 17: 102 , f. 13 (1941).

Vernacular names

• Brunei: keruing beludu kuning
• Indonesia: keruing buah, lagan sanduk (Sumatra)
• Malaysia: keruing beludu kuning (Sabah, Sarawak).

Distribution

Northern Sumatra and Borneo.

Uses

The timber is used as keruing.

Observations

• A medium-sized to large tree of up to 50 m tall, bole straight, cylindrical, up to 125 cm in diameter, buttresses few, up to 2 m tall, up to 1 m long, rounded, thick, bark surface reddish to orange-brown or paler, flaking unevenly, outer bark thin, cork cambium grey, inner bark hard, brittle, red-brown, sapwood pale, dull, ochre-yellow; buds ovoid, pale pink-brown velutinate.
• Leaves obovate, 20-40 cm × 12-15 cm (subsp. conformis) or 9-12 cm × 5-7 cm (subsp. borneensis), base obtuse or subcordate, narrowly subpeltate, acumen 4-8 mm long, secondary veins 13-15 pairs (subsp. conformis) or 15-18 pairs (subsp. borneensis), beneath persistently densely velutinous, petiole 1.5-6 cm long, stipules broadly ovate, outside pale pink-brown velutinous, caducous.
• Stamens about 30.
• Fruit calyx tube ellipsoid, persistently pubescent, with 5 incrassate wings, 2 larger fruit calyx lobes up to 10 cm × 2 cm, 3 shorter ones up to 8 mm × 8 mm.

Within D. conformis two subspecies are recognized: subsp. conformis in Sumatra and subsp. borneensis P. Ashton in Borneo. It is comparatively rare and occurs on clay-rich soils in lowland or hill dipterocarp forest up to 800 m altitude. The density of the wood is 940-980 kg/m³at 15% moisture content.

Selected sources

30, 31, 258, 476, 737, 746, 748.

Main genus page

• Dipterocarpus (Timbers)

Authors

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