Castanopsis oviformis Soepadmo, Reinwardtia 7 (1968)
Latin for 'egg-shaped', reffering to the fruits.
Tree with small buttresses, bark smooth to shallowly fissured. Twigs hairy, sparsely lenticellate.
Stipules ca. 4 mm long. Petiole with swollen base, up to c. 1.5 cm long. Leaves alternate, simple,
up to 15 by 6.5 cm, penni-veined (8-13 secondary veins), upper surface with very fine reticulate network
of tertiary veins, lower surface dull green. Male flowers ca. 2 mm diameter, whitish, placed in raceme.
Fruits ca. 38 mm long, green-yellowish, nut completely enclosed by spiny cupule, splitting irregular
or in two parts, spines c. 10 mm long.
Tree, 15-34 m by 20-59 cm diameter; buttresses small, sometimes branched; bark smooth or shallowly
fissured, greyish brown, lenticellate. Branchlets initially with brownish, adpressed stellate indumentum,
late glabrescent; rather slender, grey brownish or dark-purplish, sparsely set with minute
lenticels; terminal bud ovoid-globose, 2-3 by 2 mm, scales ovate, linear, acute. Stipules
ovate-acute, 3-5 by 2-3 mm. Leaves sometimes tending to distichy, more or less thinly coriaceous,
6-15 by 4-6.5 cm (index 2.2-3), widest somewhat below to somewhat above the middle; base c.
rounded and acute, top mostly rounded and abruptly acuminate with a tip of 0.5-1 cm; surfaces
green-brownish, above very glossy, glabrous, beneath sometimes dull, very sparsely to very
densely set with adpressed stellate scales (magnification 30-60!), sometimes with a few stellate
hairs on the nerves; midrib prominent beneath, flattish or slightly elevated above; nerves 8-13
pairs at an angle of 60-80 degrees, ascending, parallel, arcuating towards the margin; reticulation
dense, fine, scalariform, distinct underneath; petiole 1-1.5 cm, adaxially flat. Male rachis 5-15 cm,
1-2 mm diameter, bracts ovate-acute, 1-1.5 by 1 mm; male flowers in clusters of 3-7, perianth deeply
incised, lobes 6, 1-1.5 mm long, acute, with dense tomentum outside, stamens usually 12, filaments
1-1.5 mm, anthers 0.25 mm long. Female rachis 5-10 cm, androgynous inflorescence with female flowers
in its apical part; bracts 1.5-2 by 1-1.5 mm, with dense tomentum; female flowers solitary, perianth
deeply incised, lobes 6, ovate-acute, 1 by 1 mm, with dense tomentum outside, staminodes 12,
rudimentary, styles 3, cylindrical-conical, 2 mm. Cupule 0.5-l cm stalked, ellipsoid to obovoid,
with tapering base, 2.5-5 by l.5-3 cm, wall 0.5-1 mm thick, sparsely puberulous, spines arranged
in arching lines on both sides of the cupule except on the adaxial sector, solitary or in bundles,
sparsely set and 2-3 mm long to rather densely set and 8-10 mm long, unbranched, sturdy,
straight to somewhat recurved, densely fulvouspuberulous; dehiscence irregular or in two equal
halves. Fruit solitary, 2-3.5 by 1.5-2 cm, obovoid-cylindrical, wall 0.5-1 mm thick, completely
adnate to the cupule, rugose, glabrous; cotyledons flat-convex. [from Flora Malesiana]
In undisturbed to slightly disturbed mixed dipterocarp, keranga and sub-montane
forests up to 1200 m altitude. Found on alluvial sites and along rivers as well
as on hillsides and ridges. On sandy to clay soils.
The wood is locally used in house construction. The nuts are edible though somewhat bitter.
Borneo: Berangan, Berangan pipit, Buah terampayoh, Buah butoh, Terompoyoh.