窄叶青冈 zhai ye qing gang

Quercus augustinii Skan in F. B. Forbes & Hemsley, J. Linn. Soc., Bot. 26: 507. 1899; Pasania chiwui Hu; Q. augustinii var. angustifolia A. Camus; Q. augustinii var. rockiana A. Camus.

Trees to 10 m tall. Branchlets sulcate, with orangish brown scalelike glands when young, glabrescent. Petiole 0.5-2 cm, glabrous; leaf blade ovate-lanceolate to elliptic-lanceolate, 6-12 × 1-4 cm, abaxially slightly farinose, adaxially glabrous, base cuneate and usually oblique, margin slightly recurved and usually serrate in juvenile tree but entire or apically conspicuously serrate in mature tree, apex acuminate; midvein adaxially raised; secondary veins 10-15 on each side of midvein, inconspicuous, usually not fusing; tertiary veins obscure to very slender, evident. Female inflorescences solitary in axil of new shoots, 3-4 cm; cupules 5-10. Cupule cupular, 0.6-1 × 1-1.3 cm, enclosing ca. 1/2 of nut, outside glabrous or puberulent, inside grayish brown sericeous, wall less than 1 mm thick; bracts in 5-7 rings, margin entire to crenulate, basal ones somewhat spreading, apical ones connate or adherent to cupule wall. Nut ovoid to oblong-ovoid, 1-1.7 × 0.8-1.2 cm, glabrous, apex rounded to somewhat depressed; scar ca. 6 mm in diam., slightly convex; stylopodium persistent. Fl. Apr-May, fr. Oct of following year.

Forests in mountains; 1200-2700 m. Guangxi, Guizhou, Yunnan [Vietnam]