Tree to 20 m. Branchlets and inflorescences sparsely covered in ferruginous, waxy scale-like trichomes. Leaves leathery, 4–12 × 1–4.5 cm, lanceolate to ovate, upper surface glabrous, lower surface with layers of reddish or yellowish brown scale-like trichomes that turn silvery grey with age, 8–13 secondary veins on each side of the midrib, margins entire or with a few shallow teeth, apex acute to narrowly caudate; petiole ~1 cm long, base somewhat swollen. Cupules subglobose to ovoid, 1–1.5 cm diameter, bracts tuberculate or spiny (when spiny, 0.1–0.2 cm long), outer surface covered in yellowish to reddish brown, felt-like pubescence and waxy trichomes. Nuts one per cupule, subglobose to broadly conical. Flowering March to June, fruiting September to November (China). Huang et al. 1999. Distribution CHINA: Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Yunnan, Zhejiang; TAIWAN. Habitat Mixed and broadleaved evergreen forest below 1700 m asl. USDA Hardiness Zone 8–9. Conservation status Not evaluated. Illustration Huang et al. 1999; NT218.
In Taiwan Castanopsis carlesii is noted to be a large canopy tree in the broadleaved evergreen forest of the lower mountain slopes (Flanagan & Kirkham 2005), but it is too recent an introduction to be anything larger than a sapling in cultivation in the West. Its first recorded introduction seems to have been from a collection made by John L. Creech on a joint USDA–Longwood Gardens expedition to Taiwan in 1967 (Aniśko 2006), but it is not known what became of this material. A straight young tree seen at the David C. Lam Asian Garden in 2004 was extremely elegant, suggesting Ficus benjamina L. in its neat leaves and pendulous shoot tips. The leaves are elongate and acuminate, flushed bronze when young, shiny mid-green with a ‘metallic’ sheen below when mature. In 2004 the tree in the Asian Garden was 3 m tall; in November 2006 Peter Wharton reported that it was still ‘growing like a train’ and had reached over 5 m. This specimen was received in 1998 from the Taiwanese Forestry Research Institute, as seed collected at 1985 m, at Herhuanchi. A young tree (planted in 2005) is growing at Kalmthout, Belgium (Jan De Langhe, pers. comm. 2007).