16. Hypnum sakuraii (Sak.) Ando 湿地灰藓 shi di hui xian
J. Sci. Hiroshima Univ., Ser. B, Div. 2, Bot. 8: 185. 1958. Calohypnum sakuraii Sak., J. Jap. Bot. 25: 219. f. 1. 1950. Type: Japan. Shizuoka Pref., Mt. Higane, T. Haneda I44990.
Plants robust, golden reddish, purple or reddish brown, in dense tufts. Stems creeping or suberect; in stem cross section one layer of epidermal cells thin-walled, 3 layers of thick-walled outer cortical cells, inner cortical cells enlarged, hyaline, thin-walled; central strand somewhat differentiated; remotely pinnately branched, branches about 0.5–1.5 cm long; pseudoparaphyllia few, foliose. Stem leaves falcate-secund, 2.0–2.7 mm × 0.70–0.95 mm, ovate-lanceolate, shortly acuminate at apex, nearly rounded ovate at base; margins plane, serrulate near apex; costae double, very short or indistinct; basal leaf cells usually yellowish or reddish brown, alar cells excavated, consisting of several enlarged hyaline cells, usually 1–2 rows of smaller, quadrate above the inflated alar cells; branch leaves smaller and narrower, slightly concave, 1.8–2.1 mm × 0.4–0.5 mm, oblong-lanceolate; median leaf cells linear, 60–90 µm × 3 µm, often thick-walled, sometimes prorate. Dioicous. Perichaetial leaves narrowly lanceolate, very slender at apex, margins entire, sometimes laciniate below the apex, plicate, costa indistinct. Setae reddish brown, twisted when dry, about 0.5 cm long; capsules dark brown, inclined, oblong-ovoid to cylindrical, 2.0–2.5(–3.0) mm thick, suberect, sometimes slightly arcuate, smooth, not constricted below the mouth when dry; opercula shortly rostrate; annuli somewhat developed, in 2 rows; peristome perfect hypnoid, cilia 1–2. Calyptrae not seen. Spores papillose, 25–30 µm in diameter.