2. Breidleria pratensis (Koch ex Spruce) Loesk. 扁灰藓 bian hui xian
Stud. Morph. Syst. Laubm. 172. 1910. Hypnum pratense Koch ex Spruce, London J. Bot. 4: 177. 1845. Type: Britain.
Drepanium pratense (Rabenh.) Jens., Meddel. Grønland 3: 327. 1887. Hypnum curvifolium Hedw. var. pratense Rabenh., Deutschl. Krypt.-Fl. 2(3): 273. 1848.
Plants rather robust, large, yellowish green or yellowish brown, glossy, in loose tufts. Stems prostrate, ascending or erect, 4–10 cm long, irregularly or subpinnately branched, branches ascending, foliate branches flattened, pseudoparaphyllia foliose; in stem cross section epidermal cells large, thin-walled, hyaline; central strand developed. Leaves lax, complanately arranged, ovate-lanceolate, 1.6–2.0 mm × 0.6–0.8 mm, concave, not plicate, secund above, gradually to slenderly acuminate; margins plane, serrulate above; costae double, short or absent; leaf cells linear, thin-walled, basal cells shorter and broader; alar cells small, quadrate or shortly rectangular, thick-walled, not inflated; branch leaves smaller, narrowly lanceolate, falcate-secund. Dioicous. Perichaetial leaves elongate, erect, plicate. Setae elongate, ca. 3 cm long; capsules suberect or horizontal, 2.0–2.5 mm long, arcuate when dry, smooth; opercula conic, slenderly rostrate; annuli developed, in 3 rows; peristome typically hypnoid, with 2–3 cilia. Calyptrae not seen. Spores 12–16 µm in diameter, minutely papillose, brownish.