Dipterocarpus alatus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Dipterocarpus alatus Roxb. ex G. Don

Protologue: Gen. Syst. 1: 813 (1831).

Synonyms

• Dipterocarpus philippinensis Foxw. (1911).

Vernacular names

• Philippines: hairy-leafed apitong (general), apinau (Tagalog), ayamban (Iloko)
• Cambodia: chhë: ti:ël bângku:ëy, chhë: ti:ël ba:y, chhë: ti:ël tük
• Laos: (maiz) nha:ng, nha:ng kha:w
• Thailand: yang-na
• Vietnam: dầu rái.

Distribution

Burma, Thailand, Laos, Cambodia, Vietnam and the Philippines (Luzon).

Uses

The timber is used as keruing; D. alatus is a very important source of construction timber in Indo-China and Thailand.

Observations

• A medium-sized to fairly large tree of up to 40 m tall (but probably sometimes more), bole tall, straight, cylindrical, branchless for up to 20 m, up to 150 cm in diameter; buds lanceolate, yellow pubescent.
• Leaves narrowly ovate to ovate to elliptical-oblong, 9-25 cm × 3.5-15 cm, base cuneate to rounded, apex acute or shortly indistinctly acuminate, secondary veins 11-18(-20) pairs, sparsely pubescent above, beneath densely persistently pubescent, petiole 2.5-4.5 cm long, stipules greyish-yellow pubescent.
• Fruit calyx tube glabrous, subglobose, with 5 wings to 8 mm broad, 2 larger fruit calyx lobes up to 14 cm × 3 cm, 3 shorter ones up to 12 mm × 14 mm.

D. alatus occurs gregariously along rivers in Indo-China and Thailand up to 500 m altitude. There it is a rapid colonizer of alluvial soils. In the Philippines it is rare, occurring in mixed dipterocarp forest in seasonal areas at low and medium altitudes. It was recently (1993) discovered that D. alatus and D. philippinensis are conspecific. The density of the wood is 620-905 kg/m³at 15% moisture content.

Selected sources

175, 235, 258, 579, 627, 628, 748.

Main genus page

• Dipterocarpus (Timbers)

Authors

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