Phascum cuspidatum Hedw., Sp. Musc. Frond. 1801.
Plants minute, 1.3–2.0 mm high, light green or yellowish green, in loose or scattered tufts. Stems erect, usually simple; central strand absent. Leaves crowded, rosulate, appressed or slightly contorted when dry, erect-spreading when moist, ovate to obovate, 0.4–1.2 mm x 0.3–0.6 mm, acute to cuspidate at the apex; margins entire, plane or weakly revolute in the lower half; costa slender, long-excurrent, ending in a hyaline, piliferous awn, usually smooth or somewhat denticulate; upper leaf cells rounded quadrate to rhomboidal, 8–22 µm x 8–18 µm, thin-walled, usually with 1 to several C-shaped papillae, often with 2–3 rows of marginal cells smooth; basal cells enlarged, rectangular, 24–44 µm x 10–24 µm, smooth. Autoicous. Setae very short, 20–30 µm long, slightly curved; capsules immersed, globose, bluntly apiculate; opercula not developed; peristome none. Spores yellowish brown, 15–36 µm in diameter, densely papillose.
Chinese specimens examined: NEI MONGOL: Ba-lin-you-qi, X.-L. Bai 220 (NMU). SICHUAN: Song-pan Co., Allen 7090 (MO).
Habitat: on rocks or soil; Distribution: China, Mongolia, Russia, Europe, North America, and northern Africa.
Illustrations: X.-L. Bai 1997 (Pl. 60, figs. 1–6).