4. Calliergon sarmentosum (Wahlenb.) Kindb. 蔓枝湿原藓 man zhi shi yuan xian
Canad. Rec. Sci. 6(2): 72. 1894. Sarmentypnum sarmentosum (Wahlenb.) Tuom. & T. J. Kop., Ann. Bot. Fenn. 16: 223. 1979. Amblystegium sarmentosum (Wahlenb.) De Not., Comment. Soc. Crittog. Ital. 2: 289. 1867. Hypnum sarmentosum Wahlenb., Fl. Lapp. 380. 1812. Type: Norway.
Plants soft, purple-red, brownish, or blackish green, glossy, in loose mats. Stems suberect, to 15 cm long, irregularly branched, attenuate at tips, densely foliate; stem rounded in cross section; cortical cells more or less thick-walled, outmost cells small, thick-walled, in 2–4 rows, central strand weakly differentiated; pseudoparaphyllia foliose. Stem leaves erect, ca. 2.5 mm × 1.0 mm, elliptical to ligulate, involute above, rounded obtuse or apiculate, cucullate at apex, sometimes decurrent, forming small auricles at base; margins entire; costae ca. 5/6 the leaf length; median leaf cells linear-rhomboidal, thick-walled, 50–100 µm × 3–5 µm; apical cells shorter, often with a group of short, hyaline, thin-walled cells; basal cells thick-walled, often porose; alar cells hyaline, sometimes brownish, fairly large, not sharply delimited; branch leaves smaller, ca. 1.5 mm × 0.6 mm. Dioicous. Sporophytes not seen.