15. Dicranum leiodontium Card. 无褶曲尾藓 wu-zhe qu-wei xian
Bull. Herb. Boissier sér. 2, 7: 714. 1907. Type. Japan: Faurie 132.
Plants small to medium-sized, up to 2.5 cm high, yellowish green above, brownish below, in shiny tufts. Stems erect or ascending, irregularly branched, densely tomentose below. Leaves often crispate when dry, imbricate or slightly falcate-secund when moist, lanceolate, gradually or rather abruptly narrowed from an oblong-ovate base to a slender, channeled acumen; margins plane, entire below, minutely serrulate at the apex; costa stout, occupying 1/5–1/4 the leaf base width, excurrent into a slender point, mammillose at the back; upper cells rounded quadrate to short-rectangular, thick-walled, not porose, sometimes mammillose at the back of leaves; basal cells elongate, rectangular, faintly porose; alar cells quadrate, inflated, unistratose, brownish. Dioicous. Perichaetial leaves with a high convolute-sheathing base, abruptly narrowed to a short, subulate apex, papillose at the tips. Setae single, straight, yellowish green, 1.0–1.2 cm long; capsules erect, oblong-ovoid to short-cylindrical, symmetric; exothecial cells rectangular, thick-walled; opercula erect, conic-rostrate, nearly as long as the urns; annuli in 1 row of large cells; peristome teeth lanceolate, ca. 2.3 mm long, divided to the middle, papillose at the tips, vertically striolate at the base. Calyptrae ca. 3.7 mm long, roughened at the tips. Spores 17–20 µm in diameter, minutely papillose.