越南青冈 yue nan qing gang

Quercus austrocochinchinensis Hickel & A. Camus, Ann. Sci. Nat., Bot., ser. 10, 3: 386. 1921.

Trees to 15 m tall. Branchlets brownish, with stellate hairs, glabrescent, lenticellate; lenticels brownish, oblong. Petiole 1-2 cm, with stellate hairs, glabrescent; leaf blade green, oblong-elliptic to lanceolate, 10-17(-20) × 3-5 cm, thinly leathery, pubescent when young, glabrescent, base cuneate, margin beyond basal 1/3 remotely minutely serrate, apex shortly acute to acuminate; secondary veins 12-17 on each side of midvein, adaxially slightly raised; tertiary veins abaxially conspicuous. Cupule cupular, 1.3-1.5 × 1.5-1.8 cm, enclosing all but nut apex, outside and inside tawny tomentose, wall ca. 2 cm thick; bracts in 8-10 rings, margin dentate. Nut oblate, 1.1-1.4 × 1.3-1.8 cm, angular, yellowish brown tomentose, apex rounded; scar ca. 1.2 cm in diam., as large as nut base, flat; stylopodium persistent.

Sparse forests in mountain valleys and on river banks; 700-1000 m. Yunnan [Thailand, Vietnam]