13. Plagiothecium platyphyllum Mönk. 阔叶棉藓 kuo ye mian xian
Laubm. Eur. 866: 207b. 1927. Plagiothecium sylvaticum var. platyphyllum (Mönk.) F. Koppe, Abh. Ber. Naturwiss. Abt. Grenzmark. Ges. Erforsch. Heimat Schneidemuhl. 1931: 80. 1931. Type: Europe.
Plants medium-sized to rather large, green to dark green, glossy, in dense mats. Stems prostrate or ascending, irregularly branched, with leafy branches complanate. All leaves ovate-lanceolate, 2.0–2.5 mm × 1.0–1.4 mm, mostly asymmetric, complanate, sometimes slightly plicate; margins entire below, serrulate near the apex; costae double, unequal, with one branch reaching to the mid-leaf; median leaf cells linear-rhomboidal, 80–120 µm × 10–14 µm; apical cells shorter, thin-walled, hyaline, often bearing rhizoids and brood bodies at leaf apex; alar cells hyaline or grayish green, rounded-quadrate to rectangular, decurrencies consisting of 1–3 rows of cells;. Autoicous. Setae 20–30 mm long; capsules cylindrical, curved, shriveled, ca. 2.0 mm long, constricted below the mouth when dry; opercula conic-rostrate, shortly beaked; cilia 2–3. Spores 11–14 µm in diameter, papillose or nearly smooth.