Description from Flora of China
Trees or shrubs, evergreen or deciduous. Buds, branches, leaf blades, inflorescences, and flowers with sparse to dense usually stellate hairs, often mixed with simple hairs. Branches sympodial, usually pubescent at least when young. Stipules absent. Leaves alternate, simple, generally crowded near apex of twigs; leaf blade usually abaxially ± pubescent and adaxially glabrous or glabrescent, margin serrate or occasionally entire. Inflorescences terminal, usually a many-flowered slender raceme, either solitary or umbellate-clustered, sometimes sparsely branched near base and thus appearing paniculate, pubescent, bracteate. Flowers bisexual, actinomorphic. Pedicel articulated at base of sepals. Sepals 5, imbricate, persistent. Petals 5, usually white, free or coherent at base, oblong to obovate, inside often pilose from base to middle, apical margin often fimbriate, apex rounded- to truncate-emarginate. Stamens 10, in 2 whorls, distinct but generally adnate to base of petals; anthers inverted at anthesis, ± V-shaped, introrse, papillose, opening by short apical pores. Ovary superior, 3-locular, globose but apically depressed at style base, pubescent, with axile placentation; ovules 20–40 per locule. Style 1, persistent, apex usually 3-cleft or -lobed. Capsule subglobose to globose, pubescent, 3-locular. Seeds many, ovoid-subtrigonous, thin-walled, surface impressed-reticulate.
One genus and ca. 65 species: America, Asia, N Atlantic Islands (Madeira); seven species (three endemic) in China.
(Authors: Qin Haining (覃海宁) ; Peter Fritsch)
Hu Lingcheng. 1990. Clethraceae. In: Fang Wenpei & Hu Wenkuang, eds., Fl. Reipubl. Popularis Sin. 56: 120–156.