6. Clethra barbinervis Siebold & Zuccarini, Abh. Math.-Phys. Cl. Königl. Bayer. Akad Wiss. 4(3): 128. 1846.
髭脉桤叶树 zi mai qi ye shu
Clethra barbinervis var. kawadana (Yanagita) H. Hara; C. kawadana Yanagita; C. wuyishanica Ching ex L. C. Hu; C. wuyishanica var. erosa L. C. Hu.
Trees or shrubs, 1–9 m tall, deciduous. Petiole 0.6–2.4 cm; leaf blade ovate, lanceolate-ovate, elliptic, oblanceolate, or obovate, 5.2–11 × 2.8–4.8 cm, papery, abaxially appressed pilose or glabrous on major veins and often stellate-tufted in secondary vein axils, glabrous elsewhere, and reticulations dark brown but not raised, base attenuate to cuneate or occasionally obtuse to subrounded, margin sharply serrate nearly throughout or basal 1/4–1/3 entire, teeth 22–39 per side on larger leaves and 1–4 mm apart, apex acuminate; secondary veins (8–)11–14 on each side of midvein. Racemes or raceme branches (1–)3–8 per twig, 5–17 cm, grayish brown or brown stellate-tomentose but sometimes sparsely so, thickest rachis on each twig basally 0.8–1.7 mm in diam.; bracts linear-subulate, 3–6 mm. Pedicel 1.5–5.5 mm at anthesis. Sepals ovate, 2–3(–3.8) × 1.2–1.6 mm, outside densely white stellate-tomentose and surface (visible through pubescence) usually medially blackened, midvein usually indistinct at anthesis, apex obtuse. Petals white, 3–4 × 2–2.9 cm, outside smooth, inside glabrous, margin thickened and apically fimbriate. Stamens 4–5.3 mm, exserted; filaments glabrous or occasionally sparsely pilose; anthers 1.3–2 mm. Style 1.5–3.5 mm at anthesis, glabrous, apex 3-lobed to shallowly 3-cleft. Fruiting pedicel 4–9 mm. Ovary and capsule apically hirsute with longer hairs 0.7–1.1 mm; persistent style 3–5 mm. Fl. Jun–Aug, fr. Sep–Nov. 2n = 32.
Open deciduous montane forests, ± dry places; 800–1800 m. Anhui, Fujian, Hubei, Hunan, Jiangxi, Shandong (Lao Shan), Zhejiang [Japan, Korea].