23. Fissidens gymnogynus Besch. 裸萼凤尾藓 luo-e feng-wei xian
J. Bot. (Morat) 12: 292. 1898. Type. Japan: Honshu, Sengantoge, 18 XI 1894, U. Faurie 14967 (isotype H-BR).
Plants small to medium-sized, yellowish green to light brownish. Leafy stems usually unbranched, sometimes with a few branches at the base, 7–16 mm long, 1.8–3.6 mm wide; axillary hyaline nodules lacking; central strand only slightly differentiated. Leaves in 9–25 pairs, rather densely arranged, distinctly crisped when dry; the lowermost leaves smaller, becoming larger toward to the middle; middle and upper leaves lingulate to lanceolate, 1.8–2.1 mm × 0.3–0.5 mm, mucronate to acute at apex; base of dorsal laminae rounded to wedge-shaped; vaginant laminae 1¤2 –3¤5 the leaf length, unequal; costa stout, usually ending a few cells below leaf apex; margins crenulate to slightly serrulate; cells at the apex rounded-rhombic, smooth and thick-walled, forming a lighter region; cells of apical and dorsal laminae hexagonal to rounded-hexagonal, 10–14 µm long, mammillose, obscure; cells of vaginant laminae hexagonal, with thicker and clearer walls. Phyllodioicous. Archegonia terminal, about 470 µm long. Perichaetial leaves not well differentiated. Setae ca. 2.3 mm long, reddish brown; capsules erect, symmetrical; urns cylindrical, ca. 1.1 mm long.