42. Fissidens schusteri Z. Iwats. & P.-C. Wu, Nova Hedwigia Beih. 90:383. 1988.
Plants small, yellowish green or brownish. Leafy stems gregarious, mostly simple, rarely branching, 3–7 mm long, 0.75–1.50 mm wide in wet condition; axillary hyaline nodules not differentiated; cortical stem cells small, fairly thick-walled; central strand weakly differentiated; rhizoids smooth. Leaves in 7–15 pairs, laxly foliated, usually not overlapping at middle to lower parts of stems, more or less densely arranged at upper part of stems, upper leaves much larger than lower ones, lanceolate to narrowly lanceolate, 1.75–2.30 mm × 0.25–0.38 mm, narrowly acute at apex; dorsal laminae wedge-shaped at base; vaginant laminae 1/2 –2/3 the leaf length, upper part very unequal, usually open to costa; costa stout, percurrent to shortly excurrent; laminae 1 cell thick; margins entire to subentire; cells of apical laminae irregularly quadrate to hexagonal, thick-walled, lumen 5.0–12.5 µm long, smooth; limbidia distinct on vaginant laminae of middle to upper leaves, 2–6 cells wide, 1–2 cells thick. Autoicous; male inflorescences on short branches, usually from the base of stems; archegonia terminal on stems, 330–370 µm long; perichaetial leaves narrowly lanceolate. Setae 3.5-–5.0 mm long, smooth; capsules erect, almost symmetrical; urns 0.65 mm long; exothecial cells quadrate, moderately thick-walled; opercula shortly rostrate, 0.4 mm long; peristome teeth 16, ca. 210 µm long, 40–50 µm wide at base, forked down to 1/2 –2/5 the length of teeth, spirally thickened and papillose above (more distinctly spirally thickened on ventral side of teeth), densely covered by minute papillae below; annuli not differentiated. Calyptrae campanulate, 0.8 mm long, smooth to slightly scabrous. Spores 17–25 µm in diameter, almost smooth
Type. China: Sichuan, Jiang-bei Co., Boxi, on rock, P. C. Chen 5156 (holotype HIRO, isotype PE).
Specimens examined: SICHUAN: Jiang-bei Co., 1943, P.-C. Chen a & b (HIRO, PE), L.-Q. Xia 214, 251, (HIRO, PE).
Habitat: on rocks; Distribution: endemic to China.
The present species is very similar to Fissidens crassinervis in general appearance, but clearly different in having distinct limbidia on vaginant laminae. The sexuality of F. schusteri is autoicous while that of F. crassinervis is dioicous.
Illustrations: Pl. 87, figs. 1–22.