44. Fissidens serratus C. Müll., Bot. Zeitung (Berlin). 5:804. 1847.
Fissidens papillosus Sande-Lac., Verh. Kon. Ned. Akad. Wetensch., Afd. Natuurk., Tweede Sect. 13: 1, pl. 1A. 1872.
Plants small, growing in loose tufts. Leafy stems simple, 0.5–1.7 mm long, 0.5–1.7 mm wide; axillary hyaline nodules indistinct; central strand not differentiated. Leaves in 2–5 pairs, densely arranged, upper leaves lanceolate, 0.5–0.7 mm × 0.1–0.2 mm, obtuse to acute at apex; base of dorsal laminae rounded to wedge-shaped, or ending a little above the base; vaginant laminae ca. 1/2 the leaf length, unequal; costa stout, light yellow, ending a few cells below leaf apex, often dividing leaf unequally; margins of apical laminae finely serrulate, those of vaginant laminae irregularly sharply serrulate; cells of apical laminae quadrate to hexagonal, slightly thick-walled,
8–11 µm long with a distinct central papilla; cells of upper part of vaginant laminae similar to those of apical laminae, becoming larger at middle part, smooth, rectangular, up to 18 µm long toward base. Rhizautoicous. Archegonia terminal, 140–200 µm long. Sporophytes not seen.
Type. Indonesia: Java, Tjibodjas, Fleischer s.n.
Chinese specimens examined: TAIWAN: Chia-yi Co., Iwatsuki & Sharp 294 (NICH); Nan-tou Co., S.-H. Lin 12260 (NICH, TUNG, as F. papillosus).
Habitat: on tree trunks; Distribution: China, Japan, Indonesia, the Philippines, Australia, Africa, Caribbean, and throughout the Americas.
Illustrations: Z.-H. Li 1985 (Fig. 16, a–k, as Fissidens papillosus).