Lithocarpus echinifer (Merr.) A.Camus, Bull. Soc. Bot. Fr. 80 (1934)

Synonyms
Quercus echinifera Merr.

Diagnostics
Mid-canopy tree up to 35 m tall and 80 cm dbh. Stipules ca. 1 mm long. Leaves alternate, simple, penni-veined, glabrous. Flowers ca. 2 mm diameter, green-yellow, placed in racemes. Fruits ca. 38 mm diameter, greenish, nut alomost completely enclosed by spiny cupule, spines curved downwards.

Description
Tree up to 35 m tall, 80 cm diameter. Bark fissured or smooth, greyish brown; inner bark granular, yellowish to brownish. Sapwood yellowish. Twigs sparsely tomentose, warty lenticellate. Stipules linear, 5-10 x 2-5 mm. Leaves thick-coriaceous, glabrous above, densely greyish tomentose with appressed hairs below; elliptic, oblong or broadly ovate, 10-18 x (4.5-)7-10(-11) cm, base acute to cuneate, margin revolute, apex acute or acuminate, acumen 5-10 mm long; midrib raised on both surfaces, stronger below; lateral veins thin, 10-13 pairs, lax, flat above, slightly raised below, disappearing near the leaf margin, forming an angle of 45-60 degrees with the midrib; intercostal venation subscalariform, dense, obscure on both surfaces or slightly prominent below; petiole 15-25 mm long. Inflorescences male or female. Male inflorescences 6-21 cm long; bracts narrowly ovate to linear, 1.5-2 x 0.5 mm; bracteoles ovate, c. 1 x 0.5 mm. Male flowers solitary along the rachis; perianth lobes obtuse, c. 1.5 x 1 mm; stamen filaments 3-5 mm long; pistillode globose, c. 1.5 mm diameter. Female inflorescences 9-18 cm long; bracts broadly ovate, c. 1 x 0.8 mm; bracteoles rounded, c. 1 x 1 mm. Female flowers solitary along the rachis; perianth lobes acute, c. 1.2 x 0.8 mm; staminodes 12; styles cylindrical, straight, c. 1 mm long. Cupules solitary along the rachis, sessile or with stalk c. 5 mm long, obconical, 2-3 x 2.5-4 cm, densely tomentose, sparsely but regularly armed with prickles or spine-like, mostly recurved appendages; wall bony, thin, hairy, enclosing the acorn completely except for an apical opening c. 1 cm diameter. Acorns subhemispherical, 2- 3 x 3-4 cm, free part sparsely tomentose, brown; base rounded, apex flat, umbonate; wall woody, thick, most part adnate to the cupule. [from Tree Flora of Sabah and Sarawak]

Ecology
In undisturbed mixed dipterocarp and sub-montane forests up to 1800 m altitude. Usually along rivers on sandy to clay soils.

Distribution
Borneo.