1. Ceratodon purpureus (Hedw.) Brid. 角齿藓 jiao-chi xian
Bryol. Univ. 1: 480. 1826. Dicranum purpureum Hedw., Sp. Musc. Frond. 136. 1801. Didymodon purpureus (Hedw.) Hook. & Tayl., Musc. Brit. 65. 20. 1818. Syntypes. Europe: “Bryum tenue stellatum setis purpureus, Dill. Musc. t. 49, f. 51, 386; Mnium purpureum, Linn. Spec. ed. 11, 1575. 6.”
? Ceratodon sinensis C. Müll., Nuovo Giorn. Bot. Ital., n.s. 3: 104. 1896. Type. China: Shaanxi (Schen-si), Giraldi s.n., July 1894 [holotype B, probably destroyed].
Ceratodon purpureus var. rotundifolius Berggr., Kongl. Svenska Vetensk. Acad. Handl. 13(7): 44. 1875.
Plants small to medium-sized, (5–)8–20(–30) mm high, dirty green or yellowish green, in dense tufts. Stems erect, simple or sparsely branched, radiculose at base. Leaves slightly appressed or contorted when dry, erect-patent when moist, lanceolate, 1.0–2.1 mm long, gradually acuminate; margins strongly reflexed or revolute, notched or irregularly serrulate near the apex; costa stout, percurrent to shortly excurrent; upper and median leaf cells quadrate, 7–10 µm wide, slightly thick-walled, smooth; basal leaf cells short-rectangular, 13–20 µm × 7–10 µm, rather thin-walled. Dioicous. Perichaetial leaves strongly convolute-sheathing at base, shortly acuminate at apex. Setae straight, 1.0–2.0 cm long, reddish brown; capsules cylindric, strongly inclined to horizontal, reddish brown, 2–3 times as long as wide, 1.0–2.0 mm × 0.5–0.7 mm, deeply furrowed when dry, somewhat strumose at base; opercula conic-rostrate; annuli differentiated, in 2–3 rows of thick-walled cells; peristome teeth lanceolate, divided nearly to the base, bordered with a hyaline band, finely papillose, basal membrane low. Spores 11–13 µm in diameter, yellowish, smooth or nearly so.