6. Cyrto-hypnum Hampe & Lor. 细羽藓属 xi-yu xian shu
Bot. Zeitung (Berlin) 27: 455. 1869.
Plants slender, soft, yellowish green, olive green or dark green, rarely pale green, usually in lax patches. Stems creeping, ca. 2–3 cm long, rarely up to 5 cm long, irregularly pinnately to bipinnately branched; central strand usually present, rarely absent; paraphyllia densely or loosely growing on stems, sometimes also at the base of branches, rarely densely on branches, usually filamentous, ca. 1–5 cells long, rarely 10(–20) cells long, sometimes branched, apex acute, smooth or truncate, 2 or multipapillose; branches 3–5 mm long. Stem leaves remote, ovate, widely ovate to widely cordate or triangular at base, suddenly narrowed forming a lanceolate or slender apex, sometimes squarrose above, often slightly plicate; margins revolute at base or mostly revolute, serrulate or coarsely dentate, rarely entire; costa rigid, vanishing near leaf apex or 3/4 the leaf length, rarely rather weak, sometimes papillose on back, rarely hyaline; branch leaves ovate or widely ovate, rarely widely cordate to ovate-triangular, with short obtuse apex, rarely acute; leaf cells hexagonal, rounded hexagonal or rhomboidal; basal central cells mostly rectangular, thin- or slightly thick-walled, with single conical or fine papilla or multipapillae per cell. Autoicous or dioicous? Perichaetial leaves oblong, with long lanceolate apex, sometimes weakly plicate; margins entire or serrulate, rarely with several long or short hairs at the shoulder; costa sometimes excurrent forming a long hair. Setae orange red or orange yellow, slender, ca. 1.0–2.5 cm long, usually smooth or sometimes densely papillose or mammillose, rarely rough above; capsules ovoid or oblong-ovoid or shortly cylindrical, nearly horizontal to inclined; opercula conic, 0.5–1.0 mm long; peristome Hypnum-type; exostome teeth 16, mostly lightly yellowish brown, long lanceolate, hyaline above, densely papillose, transversally striate at base; endostome segments as long as the teeth, lightly yellowish, keeled, perforated; basal membrane ca. 1/2 the length of segments; cilia 1–3, nodulose, rarely rudimentary. Calyptrae cucullate, roughened at the apex. Spores 10–20 µm in diameter, smooth or finely papillose.