38. Fissidens pellucidus Hornsch. 粗肋凤尾藓 cu-le feng-wei xian
Linnaea 15: 146. 1841. Type. Suriname: Weigelt s.n.
Fissidens crassinervis Thwait. & Mitt., J. Linn. Soc. Bot. 13: 323. 1873, hom. illeg., non Fissidens crassinervis Sande-Lac., Verh. Kon. Ned. Akad. Wetensch., Afd. Natuurk. 13: 3. Pl. 2: a.1872.
Fissidens laxus Sull. & Lesq., Proc. Amer. Acad. Arts Sci. 4: 275. 1859. Type. China: Hong Kong, C. Wright s.n. (holotype FH).
Fissidens mittenii Par., Ind. Bryol. 477. 1894.
Plants small, growing in loose tufts, usually brownish or reddish brown. Leafy stems simple, 2.4–5.2 mm long, 1.0–2.1 mm wide; axillary hyaline nodules lacking; central strand weakly differentiated. Leaves in 4–12 pairs, lower leaves very small, loosely arranged; upper leaves much larger than the lower leaves, densely arranged, lanceolate, 0.7–1.4 mm × 0.2–0.3 mm, acute to narrowly acute at apex; base of dorsal laminae wedge-shaped to rounded; vaginant laminae1/2 the leaf length, unequal; costa stout, percurrent to shortly excurrent; margins crenulate to indistinctly serrulate; cells of apical and dorsal laminae quadrate to irregularly hexagonal, 10–24 µm long, thick-walled, transparent, smooth; cells of upper half of vaginant laminae similar to those of apical and dorsal laminae, but narrower toward the base. Polyoicous. Perichaetial leaves differentiated, upper end of vaginant laminae rounded, open to costa, cells at upper end of vaginant laminae elongate, irregularly rhombic, thick-walled. Archegonia 245–390 µm long. Setae 2.5–2.9 mm long, smooth; capsules erect, symmetrical; urns ovoid, 0.4–0.5 mm long; exothecial cells quadrate to broadly oblong, thin-walled with distinctly thickened corners, distinctly mammillose; opercula conic-rostrate, ca. 0.4 mm long; peristome teeth 0.28 mm long, 36 µm wide at base, spirally thickened above, densely covered by minute papillae below.