Plants yellowish green, brownish when old and forming dense tufts. Leafy stems usually creeping, simple or with innovations from axils of upper leaves, 7–18 mm long, 2.5–3.4 mm wide; axillary hyaline nodules well differentiated; central strand differentiated. Leaves in 13–45 pairs, densely arranged, the lowermost leaves much smaller than the leaves above; middle to upper leaves narrowly lanceolate, 1.5–2.4 mm × 0.25–0.40 mm, narrowly acute at apex; base of dorsal laminae rounded; margins finely serrulate; vaginant laminae ca. 3/5 the leaf length, almost equal; costa stout, shortly excurrent; cells of apical and dorsal laminae rounded-quadrate to rounded-hexagonal, 7.0–10.5 µm long, thick-walled, mammillose, walls clear; cells of vaginant laminae similar to those of apical and dorsal laminae, but with thicker walls, cells of extreme base of vaginant laminae larger, sub-quadrate, thick-walled. Dioicous. Female inflorescences terminal. Perichaetial leaves larger than stem leaves. Archegonia ca. 300 µm long. Sporophytes not seen.

Type. The Philippines: Mindanao, W. I. Hutchinson 7607 (lectotype H-BR); Panay, Iloilo Prov. Robinson 18105 (isolectotype H-BR).

Chinese specimens examined: HAINAN: Chang-jiang Co., Redfearn 35899 (MO); Jiao-luo Shan (Mt.), Z.-H. Li 2644 (H, SYS), 1974 Team 2719 (IBSC, SYS); Le-dong Co., Redfearn 36021 (MO); Ling-shui Co., Redfearn 36080 (MO). YUNNAN: Jing-hong Co., Magill et al. 8024 (MO).

Habitat: on bark of trees or rocks; Distribution: China, India, and the Philippines.

Fissidens robinsonii was reduced to a synonym of F. zippelianus (= F. crispulus) by Norris & Koponen (1987). However, var. robinsonii differs from var. crispulus by having a differentiated central strand and a more robust costa that is shortly excurrent.

Illustration: Pl. 77, figs. 1–14.