Dipterocarpus hasseltii Bl., Fl. Jav. 2 (1829)
Named after J.C. van Hasselt [1797-1823], a Dutch physician and zoologist in Java.Synonyms
Dipterocarpus basalmiferus Bl.
Dipterocarpus lampongus Scheff.
Dipterocarpus pentagonus DC
Dipterocarpus quinquegonus Bl.
Dipterocarpus subalpinus Foxw.
Dipterocarpus tampurau Korth.
Dipterocarpus trinervis (non Bl.) Foxw.
Diagnostics
Upper canopy tree up to 45 m tall and 126 cm dbh. Stem with resin. Stipules
up to ca. 120 mm long. Leaves alternate, simple, penni-veined, glabrous, lamina
folded between secondary veins. Flowers ca. 30 mm in diameter, yellow-pinkish?,
placed in unbranched inflorescence. Fruits ca. 30 mm long, green-red, with two
ca. 190 mm long wings placed on top of the nut, wind dispersed.
Description
Parts of petals expanded in bud and ovary apex densely persistently buff puberulent, calyx at first
frequently so, nerves beneath sparsely so or glabrescent, otherwise glabrous. Twig c. 4 by 2 mm
apically, somewhat compressed, black. Buds to 20 by 5 mm, falcate-lanceolate, drying black; stipules
to 12 by 1 cm, lorate-lanceolate, subacute. Leaves 9-16 by 5-10 cm, elliptic, subcoriaceous,
prominently plicate; margin +/- prominently crenate; basecuneate; acumen to 1 cm long, short; nerves
11-14 pairs, slender but prominent beneath, ascending: petioles 2.5 cm long, slender. Inflorescences
to 10 cm long, axillary, bearing to 4 +/- secund flowers. Flower buds to 3 by 1 cm, fusiform.
Stamens 30, shorter than style at anthesis; filaments c. half the length of anthers, long, broad and
compressed at base, rapidly tapering and filiform above; anthers linear, somewhat tapering distally;
appendage acicular, very slender, c. 0.66 length of anther. Ovary narrowly ovoid-lanceolate, tapering
into the very long slender filiform style; gynoecium puberulent except for the distal quarter. Fruit
pedicel to 3 by 2 mm; calyx tube to 3 cm diameter, subglobose smooth; 2 longer lobes to 22 by 3 cm,
lorate-spatulate, usually obtuse. 3-nerved, c. 9 mm wide at base; 3 shorter lobes to 15 by 13 mm,
suborbicular, subrevolute, prominent. [from Flora Malesiana]
Ecology
Lowland dipterocarp forests on well-drained but moist fertile red soils in valleys and on hillsides,
sometimes on calcareous soil, even limestone (Java); sometimes gregarious; to 600 m elevation.
Uses
Timber is commercially harvested.
Distribution
Peninsular Thailand, Peninsular Malaysia, Sumatra, Java, Lesser Sunda Islands, Borneo, Philippines.
Local names
Borneo: Beo, Kaladan, Keladan, Keruing, Keruwing, Tempuran.
