3. Fissidens beckettii Mitt. 尖肋凤尾藓 jian-le feng-wei xian
J. Linn. Soc., Bot. 13: 325. 1873. Type. Sri Lanka: Maanagalla, Central Prov., Beckett 9 (holotype NY).
Plants small, light green to brownish. Fertile leafy stems short, simple, 1.6–2.1 mm long, 1.3–1.4 mm wide; axillary hyaline nodules indistinctly differentiated; central strand lacking. Leaves in 4–5 pairs, lower leaves smaller, upper leaves much larger, 0.8–1.5 mm long, 0.2–0.4 mm wide, lanceolate to narrowly lanceolate, acute to narrowly acute at apex; vaginant laminae 1¤2–2¤3 the leaf length, upper part open to costa; margins almost entire; base of dorsal laminae wedge-shaped; limbidia continuous on upper leaves except at the base of dorsal laminae, 1–3 cells wide, 1–2 cells thick on apical laminae, 6–10 cells wide and 1–2 cells thick on vaginant laminae; costa stout, excurrent; cells of apical and dorsal laminae rhombic to oblong-hexagonal, 17–35 µm long, smooth, more or less thick-walled; cells of vaginant laminae similar to those of apical and dorsal laminae, but longer toward the base near costa, up to 42 µm long. Autoicous or rhizautoicous. Male inflorescences and perichaetia terminal, with archegonia 200–230 µm long. Setae 2.5–5.5 mm long; capsules inclined to horizontal, curved, asymmetrical; urns 0.25–0.50 mm long; exothecial cells quadrate to rectangular, thin-walled, with slightly thickened corners; opercula rostrate, 0.3 mm long; peristome teeth ca. 0.1 mm long, 31–35 µm wide at base. Spores 11–16 µm in diameter.