4. Pogonatum contortum (Brid.) Lesq. 扭叶小金发藓 niu ye xiao jin fa xian
Mem. Calif. Acad. Sci. 1: 27. 1868. Catharinella contorta (Brid.) Kindb., Rev. Bryol. 21: 35. 1894. Polytrichum contortum Menz. ex Brid., J. Bot (Schrader). 1800(2): 287. 1801. Type: North America, Menzies s.n.
Pogonatum asperrimum Besch., Ann. Sci. Nat., Bot., ser. 7, 17: 355. 1893.
Plants large, dark green, brownish green when old, tufted in large patches. Stems 5–10 cm long, usually simple. Basal leaves small, deciduous; upper leaves erect patent when moist, strongly crisped when dry, slightly constricted from rounded oval base to a broad lanceolate limb, sheathing indistinct, ca. 1 mm wide; leaf marginal cells 1–2 layers, up to 3 cells wide, rarely remotely grossly toothed, teeth consisting of several cells, light brown; costae broad, with spines on the back; lamellae ca. 40 ranks, disappearing along leaf margins, 2–3 cells high; apical cells of lamellae slightly differentiated, larger, round, 15–20 µm in diameter, thin-walled; other cells short-quadrate or nearly rectangular, 12–25 µm ×10–15 µm. Dioicous. Male plants dwarfed; perigonial leaves few. Setae single, dark brown, 20–30 mm long; capsules erect, narrowly ovoid, ca. 2.5 mm ×1.0 mm; exothecial walls mammillose; peristome teeth 32, ca. 0.25 mm long, lanceolate, obtuse at apex; membrane low. Spores 8–12 µm in diameter.