Description from Flora of China
Castanopsis formosana (Skan) Hayata; C. tribuloides (Smith) A. de Candolle var. formosana Skan.
Trees 10-26 m tall; 1st-year branchlets and leaf blades adaxially brownish black when dry; bud scales, branchlets, petiole of young leaf, mature leaf blades abaxially, and rachis of inflorescences sparsely covered with glabrescent, reddish brown, waxy scalelike trichomes. Petiole 1-2.5 cm; leaf blade ovate, ovate-elliptic, or oblong, sometimes obovate to obovate-elliptic, (4-)10-18 × (2-)4-8 cm, base rounded to broadly cuneate and inaequilateral or symmetric, margin at least from middle to apex serrate or rarely undulate, apex acute to acuminate; midvein adaxially impressed; secondary veins (5-)8-11 on each side of midvein. Female inflorescences axillary, solitary. Infructescences 10-15 cm. Cupule subglobose, 2.5-3.5 cm in diam., splitting into 3-5 segments, outside and bracts pubescent and with grayish brown, lamellate, waxy scalelike trichomes especially when young, wall 0.5-1(-1.5) mm thick; bracts spinelike, 6-10 mm, free but a few in bundles, sometimes transversely united to discontinuous rings. Nut broadly conical to ovoid, 1-2 × 1-1.5 cm, glabrous or glabrescent; scar basal, 1-1.2(-1.5) cm in diam. Fl. Apr-May, fr. Aug-Oct of following year.
Broad-leaved evergreen forests; below 1500 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, E to SC Taiwan, Yunnan, Zhejiang [Vietnam]