Dipterocarpus retusus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Dipterocarpus retusus Blume

Protologue: Cat. 's-Lands Plantentuin: 77 (1823).

Synonyms

• Dipterocarpus trinervis Blume (1823),
• Dipterocarpus macrocarpus Vesque (1874),
• Dipterocarpus pubescens Koord. & Valeton (1899).

Vernacular names

• Indonesia: keruing gunung (Java, Sumatra), palahlar minyak (Java), jati olat (Sumbawa)
• Malaysia: keruing gunong (Peninsular)
• Cambodia: chhë: ti:ël prenh
• Thailand: yang-khuan (general), tian kahom (Chong, south-eastern)
• Vietnam: chò nâu.

Distribution

India (Assam), Burma, Laos, Cambodia, Vietnam, Peninsular Malaysia, Sumatra, Java and the Lesser Sunda Islands (Bali, Lombok, Sumbawa).

Uses

The timber is used as keruing. The wood-oil is used for illumination.

Observations

• A medium-sized to large tree of up to 48 m tall, bole cylindrical, branchless for 15-20 m, up to 150 cm in diameter, bark surface slightly fissured, grey; buds ovoid-lanceolate, pale orange-rufous silky tomentose or glabrous.
• Leaves broadly elliptical-oblong, 16-28(-50) cm × 7-17(-20) cm, base obtuse, apex obtuse to emarginate, prominently plicate, secondary veins 16-19 pairs, ascending, glabrous, petiole 2.5-7 cm long, stipules lanceolate, acute, pale orange-rufous silky pubescent, glabrescent.
• Stamens 30.
• Fruit calyx tube subglobose, smooth, 2 larger fruit calyx lobes up to 25 cm × 4.5 cm, 3 shorter ones up to 2 cm × 1.5 cm.

D. retusus is locally common and semi-gregarious and occurs in moist, evergreen to semi-deciduous montane forest, at 800-1500 m altitude, but as low as 100 m in seasonal areas. The density of the wood is 640-770 kg/m³ at 15% moisture content.

Selected sources

35, 102, 140, 235, 253, 258, 318, 461, 466, 527, 628, 677, 737, 748, 793.

• Dipterocarpus (Timbers)

Authors

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