多形凤尾藓

Fissidens plicatulus Thér., Monde Pl., sér. 2, 9(45): 21. 1907. Type. China: Guizhou (Kouy-Tscheou), Pa-bong, XII 1904, Esquirol 324 (isotype S).

Plants small, yellowish green. Fertile leafy stems usually simple, ca. 3.3 mm long, 1.3 mm wide; axillary hyaline nodules indistinct; central strand not differentiated. Leaves in 5–9 pairs; lower leaves small, scaly, laxly arranged; upper leaves much larger and more densely arranged, oblong-ovate, 1.2–1.5 mm × 0.2–1.0 mm, acute or obtusely acute at apex; vaginant laminae 2/3 –4/5 the leaf length, unequal; margins almost entire; limbidia of upper leaves 1–2 cells wide on upper half of vaginant laminae, 2–3 cells wide on lower half; base of dorsal laminae broadly wedge-shaped to rounded; costa stout, ending a few cells below apex; cells of apical and dorsal laminae quadrate to irregularly hexagonal, 5–10 µm long, smooth, moderately thick-walled; cells of vaginant laminae larger than those of apical and dorsal laminae, especially toward the base near costa. Autoicous. Male inflorescences terminal on short branches. Female inflorescences terminal. Setae 2.5–3.0 mm long; capsules erect or inclined, symmetrical; urns 0.4–0.6 mm long; opercula conic, ca. 0.2 mm long. Spores 22–32 µm in diameter.

Type. India: J. D. Hooker 633 (lectotype NY).

Chinese specimens examined: SICHUAN: Jiang-bei Co., L.-Q. Xia 212 (HIRO, PE). GUIZHOU: see the type information of Fissidens plicatulus cited above.

Habitat: on soil or rocks; Distribution: China, Japan, India, and Myanmar.

In eastern Asia F. diversifolius and F. schusteri are the only species of sect. Semilimbidium with smooth laminal cells. Fissidens diversifolius is easily distinguished from F. schusteri by the much broader leaves and by the differentiation of fertile and sterile stems.

Illustrations: Pl. 78, figs. 1–16.