Plants rather soft, slender, to 10–14 cm high, pale yellowish green to yellowish brown, in loose tufts. Stem cortex in 3 layers, hyaline cells thin-walled, without fibrils; central cylinder yellowish. Stem leaves 1.5–2.0 mm × 1.7–2.5 mm, triangular-lingulate, rounded and dentate at the apex; borders narrow above, clearly widened below, ca. 1/3 the leaf width at base; hyaline cells without fibrils and pores, or rarely with fibrils in the upper cells. Branches in fascicles of 3–5, with 2–3 spreading. Branch leaves 1.5–1.8 mm × 0.8–1.2 mm, ovate to ovate-lanceolate, concave, margins involute, abruptly narrowed to a sharp, acuminate apex; hyaline cells densely fibrillose, with a few pores at the corners of upper cells on the ventral surface, with a few ringed pores on the dorsal surface; green cells in cross section nearly equilateral-triangular, exposed on the dorsal surface, enclosed by hyaline cells on the ventral surface. Dioicous. Sporophytes not seen.

Type. China: Yunnan, Bi-jiang Co., Gaoligong Shan (Mt.), Pianma, alt. 3100–3200 m., 2 Aug. 1978, M. Zang 5817 (holotype KUN; isotype MO).

Chinese specimens examined: YUNNAN: Bi-jiang Co., M. Zang 5818, 5819 (KUN).

Habitat: in bogs at the margins of forests; Distribution: endemic to China.

This species is similar to Sphagnum falcatulum, but it differs in the following features: 1) stem leaves triangular-lingulate, broader and larger; 2) the hyaline cells of stem leaves divided only in the upper cells, mostly without fibrils and pores; 3) the branch leaves abruptly narrowed to a sharp acumen, the hyaline cells without pores; and 4) the green cells of branch leaves equilateral-triangular.

Illustrations: Pl. 9, figs. 1–12.