Plants to 6 cm high, pale green, in dense tufts. Stem cortex in 1–2 layers, hyaline cells large, thin-walled, without fibrils; central cylinder yellowish. Stem leaves ca. 1.0 mm × 0.7–0.9 mm, triangular-ligulate or broadly ligulate, truncate and dentate or lacerate at the apex; borders narrowly differentiated; hyaline cells often with membrane pleats, densely fibrillose on both surfaces, with pores at the opposite ends along commissural rows on the dorsal surface, with 1 pore at the corners of each cell on the ventral surface. Branches in fascicles of 3–4, with 2 spreading. Branch leaves 1.3–1.4 mm × ca. 0.9 mm, oblong-ovate, rounded-truncate and dentate at the apex; margins involute and borders differentiated; hyaline cells densely fibrillose and porose, similar to those of stem leaves; green cells in cross section narrowly elliptic, centrally located, slightly exposed on both surfaces. Dioicous. Sporophytes not seen.

Type. South America.

Chinese specimens examined: NEI MONGOL: Wu-feng Shan (Mt.), P.-C. Chen & C. Gao 998 (IFSBH, KUN, MO).

Habitat: on wet ground near streams; Distribution: China and South America.

Illustrations: C. Gao (ed.) 1994 (Pl. 15, figs. 1–9).