7. Cyrto-hypnum pygmaeum (Schimp.) Buck & Crum 多疣细羽藓 duo-you xi-yu xian
Contr. Univ. Michigan Herb. 17: 67. 1990. Thuidium pygmaeum Schimp. in B. S. G., Bryol. Eur. 5: 162. 1852. Type. U.S.A.: Ohio, Columbus.
Thuidium perpapillosum R. Watanabe, J. Jap. Bot. 34: 280. 1959.
Plants slender, small to medium-sized, 1–3 cm long, dark green to yellowish green, brownish when old, in small, interwoven mats. Stems creeping, regularly bipinnately branched; central strand present; paraphyllia filamentous, only on stems, apical cells 2–4 long, papillose; surfaces of both stems and branches papillose. Stem leaves remote, appressed when dry, triangularly ovate, 0.3 mm long, acuminate at apex; margins serrate, revolute; costa hyaline, ending at upper portion of leaves, smooth on back; median leaf cells quadrate to polygonal, 5–12 µm wide, thin walls, 3–8 papillae per cell, apical cells 1–3 long, papillose or smooth; branch leaves concave, incurved when dry, narrowly ovate to triangular, apex short, 0.2 mm long. Autoicous. Perichaetial leaves oblong-ovate, acuminate to lanceolate toward apex; margins serrate above. Setae slender, yellowish brown to reddish brown, ca. 1 cm long, smooth; capsules oblong-ovate, curved, reddish brown; exostome teeth yellowish brown; endostome segments lightly yellowish or hyaline, finely papillose; basal membrane 1/2 the height of endostome segments; cilia 2. Spores ca. 10 µm in diameter, minutely papillose.