5. Orthomnion nudum Bartr. 裸帽立灯藓 luo mao li deng xian
Ann. Bryol. 8: 11. 1936. Type: China. Guizhou, Mt. Fanjing, alt. 2000 m, Q.-Y. Jiao 828 (isotype HKAS).
Plants rather robust. Primary stems prostrate; secondary stems erect, ca. 4 cm high, with dense, brownish rhizoids at base. Leaves distant, crisped when dry, spreading when moist, ovate-elliptical, ca. 3 mm long, abruptly acute at apex, somewhat decurrent at base; margins entire, broadly bordered by 3–5 rows of linear, yellowish cells nearly throughout; costae ending below the apex; leaf cells lax, large, pentagonal to hexagonal, thick-walled, clearly porose. Dioicous. Inner perichaetial leaves narrowly lanceolate, acuminate, costae ending in the leaf apex. Setae clustered, ca. 8–10 mm long, smooth; capsules erect, ovoid; opercula conic, shortly rostrate; peristome double; exostome teeth narrowly lanceolate, densely papillose; endostome segments reduced, usually with only basal membrane remaining, orange-red, ca. 1/3 the height of the teeth. Calyptrae cucullate, naked. Spores brownish, 25–28 µm in diameter, papillose.