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

Synonyms
Castanea tungurrut Blume
Castanea tungurrut forma sumatrana Miq.
Castanopsis conspersispina Merr.
Castanopsis ridleyi Gamble

Diagnostics
Tree with rough fissured bark. Stipules boat-shaped, ca. 5 mm long. Petiole up to c. 1.5 cm long. Leaves alternate, simple, up to 15 by 6 cm, penni-veined (11-19 secondary veins), lower surface whitish. Male flowers ca. 1.5 mm diameter, yellowish, placed in racemes. Fruits ca. 30 mm long, green-reddish, nut completely enclosed by spiny cupule, non- or iregularly splitting, spines up to 23 mm long.

Description
Tree, 20-37 m by 92 cm diameter; bark rough, fissured. Branchlets initially with fulvous tomentum, later glabrescent, rather sturdy, dull greyish black, smooth, sparsely lenticellate; terminal bud ovoid- ellipsoid, 3-5 by 2-3 mm, scales ovate, elliptic, acute, 3-4 by 2 mm. Stipules boat-shaped, ovate- triangular, 4-6 by 2-3 mm. Leaves (8-)12-15(-23) by (3.5-)5-6(-9) cm (index 2-3), widest about the middle to slightly below; base rounded-acute, sometimes asymmetrical, top tapering and subacuminate; more or less discolorous, above rather glossy, green-brownish, glabrous, beneath dull with a faint greyish tinge, densely covered with a waxy mass in which stellate scales are very closely adpressed (magnification 60!), and also with some longer hairs (the latter in Sumatra almost wanting); midrib prominent on both surfaces, stronger beneath; nerves 11-19 pairs at an angle of 60-70 degrees parallel, arcuating and disappearing near the margin, prominent beneath, flattish above; reticulation fine, dense, scalariform, sometimes obscure above; petiole (0.5-)1-1.5(-2) cm, adaxially flat or shallowly sulcate. Inflorescences male, female, or androgynous. Male rachis 10-25 cm by 1-2 mm; bracts and bracteoles ovate-acute, 2-3 by 1-1.5 mm, hairy outside; male flowers in clusters of 3, perianth deeply incised, lobes 5-6, acute. 2-2.5 by 1-1.5 mm, hairy on both sides, stamens 10-12, filaments 3-4 mm, anthers 0.2-0.25 mm long, pistillode 1.5 mm diameter. Female or androgynous rachis 5-15 cm, bracts thick-coriaceous, ovate-acute, 2-2.5 mm, densely hairy outside; female flowers solitary, perianth lobes 5-6, acute, 0.7-1 mm, densely hairy, staminodes 12, rudimentary, styles 3, conical, recurved, 2-2.5 mm. Young cupule sessile, ovoid, on the rounded lateral sides with spine-like tubercles, on the flat median sides scaly. Ripe cupule subsessile, obovoid-ellipsoid, 5-6 by 3-4 cm; wall 1-2 mm thick, covered partly with fulvous puberulence, and mostly all over with scattered bundles of slender spines branched in the basal half and easily reflexed 10-23 mm long, sparsely puberulous; dehiscence none or irregular. Fruit solitary, ovoidellipsoid, 3-4 by 1.5-2 cm, wall 1 mm thick, completely adnate to the cupule, when ripe rugose and glabrous; cotyledons flat-convex. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp forests up to 1500 m altitude. In swamps, along rivers and on hillsides.

Distribution
Peninsular Malaysia, Sumatra, Java, Borneo.

Local names
Borneo: Barangan.
Sumatra: Kalimorot, Tungereut.