Description from Flora of China
Quercus glabra Thunberg in Murray, Syst. Veg., ed. 14, 858. 1784; Kuromatea glabra (Thunberg) Kudo; Lithocarpus thalassicus (Hance) Rehder; Pasania glabra (Thunberg) Oersted; P. sieboldiana (Blume) Nakai; P. thalassica (Hance) Oersted; Q. sieboldiana Blume; Q. thalassica Hance; Q. thalassica var. obtusiglans Dunn; Synaedrys glabra (Thunberg) Koidzumi.
Trees to 15 m tall; branchlets and rachis of inflorescences densely tawny tomentose. Petiole 1-2 cm, tomentose when young; leaf blade obovate, obovate-elliptic, or oblong, 6-12 × 2.5-5.5 cm, leathery to thickly papery, abaxially with dense scalelike glands and shortly tomentose when young, base cuneate, margin entire or with 2-4 teeth on apical part, apex abruptly acute, shortly acute, or long acuminate; secondary veins rarely over 10 on each side of midvein; tertiary veins abaxially usually not visible. Male inflorescences in a panicle or solitary in leaf axils, to 15 cm. Female inflorescences often with a few male flowers; cupules in clusters of 3(-5). Infructescences ca. 6 cm; rachis usually pubescent. Cupule plate- to cupular, 5-10 mm × 1-1.5 cm, enclosing 1/5-2/5 of nut, wall to 1.5 mm and woody near base; bracts imbricate or connate into concentric rings, triangular, small, appressed, densely puberulent. Nut ellipsoid, 1.2-2.5 × 0.8-1.5 cm, ± white glaucous, apex pointed, wall 0.5-1 mm thick; scar 3-5(-8) mm in diam., concave. Fl. Jul-Nov, fr. Jul-Nov of following year.
Mixed mesophytic forests, frequent on sunny slopes; below 1500 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Taiwan, Zhejiang [Japan]