Description from Flora of China
Clethra annamensis Dop; C. fabri var. brevipes L. C. Hu; C. fabri var. laxiflora W. P. Fang & L. C. Hu; C. liangii H. L. Li; C. smithiana W. P. Fang; C. smithiana var. latifolia C. Y. Wu; C. tonkinensis Dop.
Trees or shrubs, 2–7 m tall, evergreen but apparently deciduous in SE portion of range. Petiole 3–15 mm; leaf blade oblanceolate or occasionally elliptic to obovate-elliptic, 5.1–12.4 × 1.5–4.2 cm, thickly papery to subleathery, abaxially often pubescent along midvein and in axils of secondary veins but otherwise glabrous and with usually slightly raised tawny reticulations, base acute to cuneate, margin shortly serrate but basal 1/4–1/2 and apical acumen entire, teeth 5–19(–31) per side on larger leaves and 1–18 mm apart, apex acuminate; secondary veins 7–13 on each side of midvein. Racemes (1–)2–7 per branchlet, 6–20 cm, densely grayish brown stellate-hirsute, thickest rachis on each twig basally 0.8–1.7 mm in diam.; bracts linear-lanceolate, 2–6 mm. Pedicel 1–4 mm at anthesis. Sepals suborbicular to ovate, 2.5–3 × 1.5–1.8 mm, densely stellate-pubescent, midvein abaxially indistinct at anthesis, apex obtuse and glandular-mucronate. Petals white or cream-white, 2.8–4.5 × 1.5–2.4 mm, abaxially smooth, adaxially villous from base to middle, margin thickened and apically distinctly fimbriate. Stamens 2.8–6.0 mm, slightly exserted or ± equal in length to petals; filaments glabrous; anthers 1.0–1.8 mm. Style 2.5–5 mm at anthesis, glabrous, apex subcapitate, 3-lobed, or shallowly 3-cleft. Fruiting pedicel 1–7 mm. Ovary and capsule apically hirsutulous, with longer hairs 0.4–0.8 mm; persistent style 3–5 mm. Fl. Jul–Aug, fr. Aug–Oct.
Dense shaded forests, open grassy slopes; 300–2000 m. Guangdong, Guangxi, Guizhou, Hainan, Hunan, Yunnan [Vietnam].