1. Rhizomnium gracile T. Kop. 纤细毛灯藓 qian xi mao deng xian
Ann. Bot. Fenn. 10: 16. 1973. Mnium gracile (T. Kop.) Crum & Ander., Mosses E. N. Amer. 1: 604. 1981, hom. illeg. Type: Canada. Manitoba, Crum 6679.
Plants small, slender, in loose tufts. Stems erect, not branched, ca. 1.0–1.5 cm high, densely radiculose at base. Leaves sparse, crisped when dry, spreading when moist, broadly obovate or nearly rounded, narrowed and slightly decurrent at base, rounded-obtuse at apex; margins entire, narrowly bordered by a single row of elongate-rectangular cells above mid-leaf, by 2 rows of rectangular cells below, marginal cells not or scarcely porose; costae ending above mid-leaf or below the apex, smooth at back; leaf cells hexagonal or slightly elongate, 80–130 µm × 50–80 µm, often regularly and obliquely arranged, cell walls uniformly thickened. Dioicous. Sporophytes not seen.