Quercus formosana Skan in F. B. Forbes & Hemsley, J. Linn. Soc., Bot. 26: 513. 1899; Pasania formosana (Skan) Schottky; Synaedrys formosana (Skan) Koidzumi.

Trees tall. Young shoots ± sulcate, glabrous. Petiole 1-1.3 cm, base ± thickened; leaf blade elliptic to sometimes obovate-elliptic and ± recurved, 5-8 × 2-3 cm, thickly leathery, rigid and crustaceous when dry, abaxially glaucous, turning grayish brown when dry, and with adherent, waxy scalelike trichomes, adaxially glabrous, base cuneate and decurrent on petiole, margin entire, apex rounded; secondary veins 7-11 on each side of midvein, abaxially slightly raised or not; tertiary veins not visible or very slender, evident. Male inflorescences congested at apex of branches, 3-6 cm. Female inflorescence with cupules solitary, scattered on rachis. Infructescence ca. 3 cm; rachis equaling branches in thickness. Cupule discoid, ca. 3 mm × 1.2 cm; bracts imbricate, triangular, small, appressed, grayish tomentose. Nut broadly conical, ca. 1.3 × 1.6 cm, glabrous, apex pointed; scar ca. 8 mm in diam., concave. Fl. Feb-Mar, fr. Sep-Nov.

* Mixed mesophytic forests; 100-500 m. S Taiwan