Description from Flora of China
Castanopsis echinocarpa var. seminuda W. C. Cheng & C. S. Chao; C. longispicata Hu; C. tribuloides (Smith) A. de Candolle var. echinocarpa (J. D. Hooker & Thomson ex Miquel) King ex J. D. Hooker.
Trees 7-15(-25) m tall. Branches glabrous; branchlets dark brown to brownish black when dry. Petiole 1-1.5 cm; leaf blade elliptic, ovate, or lanceolate, (5.5-)7-12.5(-14.5) × (1.5-)2.5-5(-6) cm, thickly papery, abaxially covered with a very tight layer of scalelike trichomes and reddish brown to yellowish brown when young but grayish brown with age, base rounded to sometimes acute, margin serrate to rarely subentire, apex acuminate to abruptly narrowly caudate; midvein adaxially slightly impressed to rarely nearly flat; secondary veins 9-13 on each side of midvein. Rachis of inflorescences glabrous or glabrescent. Infructescence rachis base 2-3.5 mm thick. Cupule globose, 1.5-2 cm in diam., rarely splitting, wall ca. 1 mm thick; bracts spinelike, thick, 1-3 mm, sometimes no more than tubercles, 3- or 4-angular in cross section, pale grayish brown pubescent, sometimes base loosely connected to discontinuous rings. Nut 1 per cupule, subglobose to conical, 1-1.3 cm in diam., glabrous, apex acute; scar basal, 8-9 mm in diam. Fl. Apr-May, fr. Sep-Oct of following year.
Broad-leaved evergreen forests; 500-2300 m. SE Xizang, S Yunnan [Bangladesh, Bhutan, NE India, Myanmar, Nepal, Thailand, Vietnam]