Castanopsis acuminatissima (Blume) A.DC., J. Bot. 1 (1863)

Synonyms
Castanea acuminatissima Blume
Castanea sessifolia Blume
Castanopsis bejaudii A.Camus
Castanopsis junghuhnii (Miq.) Markgr.
Castanopsis longispicata Hu
Castanopsis nebularum Hickel & A.Camus
Castanopsis schlenkerae Bailey
Castanopsis sessilifolia A.DC.
Pasania acuminatissima Oerst.
Quercus acuminatissima (Blume) A.DC.
Quercus fagiformis Jungh.
Quercus junghuhnii Miq.
Quercus lineata Miq.
Quercus varingaefolia Miq.
Synaedrys acuminatissima (Blume) Koidz.
Synaedrys fagiformis Koidz.

Diagnostics
Tree with buttresses and sometimes with lots of small sprouts around the base of the tree. Branches first densely hairy, later glabrous. Stipules ovate, 4 by 1 mm, dropped early. Leaves elliptic, with widest point below or near middle, with or without teeth along upper part of leaf margin, up to 17 by 6 cm, lower surface shiny brownish-golden, with 10-14 secondary veins. Fruits completely covered by cupule, ca. 1.5 cm, covered with scales or flat spines up to 2 mm long, splitting open in two parts.

Description
Tree, 10-42 m by 30-90 cm diameter; buttresses to 2 m tall, 1.34 m out ; bark greyish brown, rough, fissured, inner bark 1-2 cm thick, pale to reddish brown. Branchlets initially with a dense layer of rufous fimbriate scales and adpressed stellate hairs; slender, later glabrescent, with minute lenticels, greyish black, finely fissured, at the base with scars of the bud scales; terminal bud ovoid or flat- ellipsoid, mostly found when having attained a size of 4-8 by 2-3 mm, apparently waiting for some time before developing further, the scales imbricate or mostly distichous, membranous, ovate- acute, 1-1.5 by 1-1.2 mm, densely hirsutely ciliate, persistent for some time. Stipules ovate-acute, 3-4 by 1 mm, caducous. Leaves thin coriaceous, 4.5-17 by 2.5-6 cm (index 2.4-3.5(-4)), widest at or below the middle; base rounded or attenuate, acute to sometimes decurrent, margin entire and undulate or remotely serrate in the apical half, top tapering and acuminate with sharp tip 1-2.5 cm; surfaces discolorous, above glossy green, glabrous, underneath dull brown to sometimes silvery with a mostly thick cover of adpressed scales, no hairs; midrib and nerves prominent beneath, flattish or slightly sunken above; nerves 10-14 pairs at an angle of 45-60 degrees, subparallel, ascending, arcuating and disappearing towards the margin, reticulation fine, scalariform or irregular, obscure on both surfaces; petiole 0.5-l cm, adaxially flat. Inflorescences male, female, or androgynous. Male rachis 5-10 cm, slender with sparse simple hairs, bracts ovate-acute, membranous, 1-2 by 1-1.5 mm, ciliate, bracteoles reduced to a cluster of simple hirsute hairs; male flowers densely arranged but solitary, perianth lobes 6, almost free, ovate-rounded, 1-2 by 1.5 mm, membranous, ciliate, stamens 12-14, filaments slender, 2-3.5 mm, anthers 0.3-0.45 mm long, pistillode rudimentary, 1-1.5 mm diameter. Female and androgynous rachis 5-10 cm, slender, with sparse simple hairs, bracts ovateacute, l.5-2 by 1-1.2 mm, membranous, densely ciliate, bracteoles 1 by 0.7 mm; androgynous rachis with a few female flowers in the apical part; female flowers solitary, perianth membranous, deeply incised, lobes 6, 1-1.2 by 0.7 mm, densely hairy, staminodes 12, styles 3, recurved, cylindrical, 1-1.5 mm, sparsely tomentose at the base. Young infructescence 10-15 cm, carrying 10-20 young cupules more or less ovoid-globose, sessile, enclosing the fruit except for the persistent perianth and styles, surface covered all over with scale-like appendages. Ripe cupule 1-1.5 by 0.7-1.2 cm, (sub)sessile, more or less globose with the fruit partly emerging; wall 0.5-l mm thick, inside sparsely hairy, outside densely grey-fulvous puberulous, rather densely set with acroscopical firm scales or small flat-triangular spines, irregular or in 5-7 c. regular transversal rows, to 2 mm long with a sharp glabrous tip or obtuse; dehiscence irregular or medianly into 2 equal segments. Fruit solitary, ovoid-conical, pointed, 1-1.5 by 0.5-l cm, longitudinally ribbed (also in the fresh state?), scar flat or rounded, c. 0.25 part, the remainder free, with dense rufous tomentum, glabrescent. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp to sub-montane forests up to 2500 m altitude. Mostly on hillsides and ridges with sandy to clay soils. In New Guinea it may form pure stands on ridges up to 1500 m.

Uses
The bark yields tannin and the nuts are edible.

Distribution
From India, Southern China and Japan via Indochina, Philippines and Indonesia to New Guinea.

Local names
Borneo: Berangan, Berangan pipit, Empili, Kogopon, Mempening, Ukam.
English: White Oak, New Guinea Oak, Papua New Guinea Oak.
Indonesia: Riung anak.