20. Grimmia pulvinata (Hedw.) Sm. 垫丛紫萼藓 dian-cong zi-e xian
Engl. Bot. 24: 1728. 1807. Dryptodon pulvinatus (Hedw.) Brid., Bryol. Univ. 1(1): 196. 1826. Campylopus pulvinatus (Hedw.) Brid., Muscol. Recent. Suppl. 4: 75. 1819. Trichostomum pulvinatum (Hedw.) Web. & Mohr, Bot. Taschenbuch. 109. 1807. Dicranum pulvinatum (Hedw.) Lag., D. García & Clemente, Anales Ci. Nat. 5(14): 176. 1802. Fissidens pulvinatus var. communis Hedw., Sp.. Musc. Frond. 158. 1801, nom. illeg. incl. typ. spec. Fissidens pulvinatus Hedw., Sp. Musc. Frond. 158. 1801. Type. Germany: “in tectis et muris vulgaris, vere malurans” (lectotype G, designated by T. Cao & Vitt 1986).
Plants up to 1.5–2.0 cm high, yellowish green above, brownish below, in small, dense, hoary cushions. Stems moderately branched, with well developed central strand in cross section. Leaves imbricate, erect when dry, spreading when moist, 2.2–3.1 mm long, elliptic- to oblong-lanceolate, obtusely keeled above, ending in a long, slender, faintly toothed hyaline hair-point, up to half to full length of leaf; margins narrowly recurved on one or both sides in the lower part, thickened and bistratose toward apex; costa percurrent, consisting of small abaxial cells in cross section; upper cells more or less unistratose except at margins, rounded-quadrate, with incrassate and slightly sinuose walls, 5–7 µm wide; median cells quadrate to short-rectangular, 9–11 µm × 6–8 µm, with nearly straight walls; basal cells short-rectangular to rectangular, almost uniform in size, straight and thin-walled, 11–40 µm × 7–9 µm. Autoicous. Perichaetial leaves larger than upper stem leaves, with elongate hyaline hair-points; perigonia located just below perichaetia. Setae long, distinctly curved when moist; capsules horizontal or pendent, elliptic, distinctly 8-striate when dry; exothecial cells rounded-hexagonal to elongate-hexagonal, thin-walled; stomata present near base of urn; annuli consisting of well developed elongate cells with thick walls; opercula with short, straight or somewhat oblique beaks; peristome teeth erect, lanceolate, yellowish brown to reddish brown, imperfectly cleft in 2–3 branches and perforate above; both outer and inner surfaces densely papillose above, papillose below. Calyptrae mitrate. Spores 10–12 µm in diameter, minutely granulose.