Dryobalanops oblongifolia Dyer, J. Bot. 12: 100 (1874)

Synonyms
Baillonodendron malayanum Heimerl
Dryobalanops abnormis Sloot
Dryobalanops beccariana Ridl.
Dryobalanops ovalifolia I.H.Burkill

Diagnostics
Large emergent trees up to 60 m tall and 150 cm diameter with large buttresses, most parts glabrous but young twigs are densely soft hairy. Stipule small, up to 3 mm long. Leaves alternate, 6-20 by 4.5-6.5 cm, widest point near the base of the leaf, venetion indistinct on upper side. Inflorescence up to 14 cm long, branched, with up to six flowers. Flowers white. Fruit glabrous, wings (calyx lobes) shorter than nut, nut ca. 3.5 by 2.7 cm.

Description
Large emergent trees up to 60 m tall and 150 cm diameter, with large buttresses. Young twigs caducously shortly evenly densely pale fulvous pubescent; vegetative parts otherwise glabrous. Twig c. 2 mm at apex, terete, smooth, lustrous. Bud to 2 by 1 mm, small, conical, acute. Stipule to 3 by 1 mm, linear, fugaceous. Leaf 6-20 by 4.5-5(-6.5) cm, narrowly oblong, frequently undulate, base broadly cuneate to obtuse, apex cuspidate with 1.5 cm long slender acumen; nervation evident but not prominent beneath, obscure above; midrib depressed above, prominent beneath. Petiole 5-14 mm. Panicle to 14 cm long, terminal or axillary, angular or terete, densely shortly evenly rufous pubescent; singly branched, branchlets to 3 cm long, bearing to 6 distichous flowers; bracteoles minute, fugaceous. Flower buds to 8 by 5 mm, ovoid, glabrous. Sepals subequal, ovate, acute, glabrous. Petals white, oblong, glabrous. Stamens c. 40, unequal, reaching to below the style apex; filaments connate at base, broadly lorate, tapering below the anther insertion, c. 0.5 times the length of anther; anther linear; appendage to connective +/- erect, exceeding anther apex. Ovary ovoid, glabrous; style 2-3 times as long as ovary, filiform, glabrous. Fruit entirely glabrous. Pedicel short, merging with calyx. Calyx lobes to 5 by 7 mm, deltoid, acute, incrassate, frequently reflexed, bordering a to 1.5 cm deep, to 1.5 cm diameter massive incrassate cup. Nut to 3.5 by 2.7 cm, ellipsoid to obovoid, obtuse to mucronate, prominently lenticellate. [from Flora Malesiana]

Ecology
Along streams, in fresh water swamps and on hill sides up to 600 m elevation.

Uses
The timber is used. The nut is edible.

Distribution
Peninsular Malaysia, Sumatra and Borneo.

Local names
Borneo: Empedu (Sarawak), Kalansau (Iban).
Malaysia: Keladan, Kapur paya, Kapur kuras.
Sumatra: Kapur guras, Petanang.