Fissidens oblongifolius var. hyophilus Hook.f. & Wils., London J. Bot. 3:547. 1844; Fissidens hyophilus Mitt., Trans. Proc. Roy. Soc. Victoria 19: 92. 1882.
Fissidens formosanus Nog., J. Hattori Bot. Lab. 7: 63. 1952. Type. China: Taiwan, Taihoku, Noguchi 5965 (holotype NICH).
Plants small, yellowish green, growing in dense tufts. Leafy stems simple or branched, 3.0–8.5 mm long, 2.0–3.5 mm wide; axillary hyaline nodules not differentiated; central strand slightly differentiated. Leaves in 4–14 pairs, densely arranged, the lowermost leaves very small, becoming larger upward; middle to upper leaves lanceolate, 1.3–2.0 mm × 0.2–0.3 mm, obtusely acute to obtuse at apex; base of dorsal laminae rounded; vaginant laminae 1/2 the leaf length, unequal; costa flexuose, light yellowish brown, ending far below leaf apex; margins serrulate by projecting cells; cells of apical and dorsal laminae sub-isodiametric, 4–7 µm long, thin-walled, distinctly mammillose; cells of vaginant laminae quadrate to hexagonal, larger than those of apical and dorsal laminae, less mammillose, with thicker walls. Autoicous. Male inflorescences usually axillary or terminal or lateral branches. Perigonial leaves well differentiated, ca. 0.9 mm long, 0.2 mm wide. Female inflorescences terminal on main or lateral stems. Perichaetial leaves slightly differentiated with upper part of vaginant laminae open to costa. Archegonia 330–360 µm long. Setae ca. 4 mm long, smooth; capsules erect, symmetrical to slightly asymmetrical; urns ovoid, ca. 0.7 mm long; exothecial cells rounded-quadrate to shortly rectangular, thin-walled, with thickened corners; opercula long rostrate, 0.7 mm long; peristome teeth ca. 0.32–0.33 mm long, 70 µm wide at base, irregularly spirally thickened distally, with minute papillae below. Calyptrae campanulate, ca. 1 mm long. Spores 11–14 µm in diameter, smooth.
Type. Australia: Qeeensland, von Mueller s.n. (holotype NY).
Chinese specimens examined: HAINAN: Ba-wang-ling (Mt.), 1974 Team 3213 (H, IBSC, SYS), P.-J. Lin & L. Zhang 66 (MO); Jian-feng-ling (Mt.), P.-C. Chen et al. 748 (PE, SYS).
Habitat: on branches of shrubs or on rocks; Distribution: China, Japan, Australia, and New Zealand.
Illustrations: Z.-H. Li 1985 (Fig. 18, i-s, as Fissidens formosanus).