Volume 9 > Part 3 > Year 2008 > Page 237 > Fagaceae > Castanopsis

30. Castanopsis siamensis Duanmuwfo-0000815159

Sci. Silvae Sin. 8: 189. 1963. Fig. 33.

Accepted Name : This is currently accepted.

Description : Tree, to 20 m high. Twigs ferruginous when young, then glabrescent, angulate and lenticellate. Leaves oblong or obovate-oblong, rarely elliptic, 11–20 by 4.5–8 cm; base cuneate; apex acute; margins serrate; coriaceous, glabrous on the upper surface, tomentose then glabrescent on the lower; midrib prominent on the lower surface, slightly depressed on the upper; lateral nerves 16–18 pairs, narrowly ridged on the lower surface, subdepressed on the upper, scalariform veins conspicuous on both surfaces. Petiole 1–2 cm long, flattened adaxially, glabrescent. Inflorescences male and female separate or mixed. Male inflorescences always branched, terminal or axillary, spikelets 7–15 cm long. Male flowers yellowish-cream, scented, in 1–8–10-flowered cluster; calyx 6-lobed, lobes free, ca 1 by 0.5 mm, glabrous; bracts ovate, glabrous; stamens (10)–12, 1–1.5 mm long, glabrous; rudimentary ovary ca 1 mm in diam. Female inflorescence spike, axillary, 8–12 cm long, other characters as in male flowers; styles 3; stigmata straight to divergent. Fruits subglobose or obconical, 1.5–3.2 by 1.3 cm (including cupule), on erect infructescence 15–20 cm long, fruit-stalk 0.5–1 cm. Cupule enclosing up to three-quarters of the nut (when young completely enclosed except around the umbo); wall with thin, imbricate and tomentose scales or lamellae; more or less conspicuously 5–6 ringed when mature with truncate apex. Nut 1 per cupule, ovoid, conical, ca 1.2 by 1 cm, glossy brown; scar upcurved, ca 1 cm in diam.

Thailand : NORTHERN: Chiang Rai (type: Rock 1580).

Distribution : Endemic to Thailand.

Ecology : Mixed deciduous to lower montane pine-oak forests, 400–1,000 m alt.

Vernacular : Ko mae lao (ก่อแม่ลาว), ko sa yam (ก่อสยาม)(Northern).