1. Calliergon cordifolium (Hedw.) Kindb. 湿原藓 shi yuan xian
Plants robust, green or yellowish green, in loosely caespitose mats. Stems erect or ascending, to 7–15 cm long, loosely irregularly branched. Stem leaves distantly foliate, erect spreading, 1.8–3.5 mm × 1.0–1.6 mm, cordate to ovate-cordate, rounded, sometimes cucullate at apex; margins entire; costae single, subpercurrent, ending in a few cells below leaf apex; median leaf cells vermicular or linear-hexagonal, 10–20 times as long as wide; apical cells shortly ovate or rhomboidal, with a small group of hyaline, short, initial cells usually present near costa at apex, 4–6 times as long as wide; alar cells numerous, hyaline, thin-walled, extending close to costa at leaf base, not forming a sharply delimited group, more or less forming auricles. Dioicous. Setae 40–70 mm long, reddish; capsules 2–3 mm long, inclined, curved, cylindrical; endostome segments slightly carinate; cilia developed, 2–3, as long as the segments, nodulose. Spores 13–18 mm in diameter, roughened to finely papillose.
Canad. Rec. Sci. 6(2): 72. 1894. Amblystegium cordifolium (Hedw.) De Not., Comment. Soc. Crittog. Ital. 2: 289. 1867. Acrocladium cordifolium (Hedw.) P. W. Richards & E. C. Wallace, Trans. Brit. Bryol. Soc. 1(4): 25. 1950. Hypnum cordifolium Hedw., Sp. Musc. Frond. 254. 1801. Type: Germany.