五列泥炭藓

Sphagnum plumulosum Röll var. quinquefarium (Lindb.) Röll, Flora 69: 89. 1886.

Plants variable in size, color, and habit, sometimes up to 20 cm high, usually grayish green or bright green, tinged with pinkish or purple. Stem cortex in 3–4 layers, hyaline cells large and thin-walled, without fibrils, with large membrane gaps; central cylinder yellowish green. Stem leaves 1.0–1.5 mm × 0.7–0.9 mm, variable, usually broad at base, isosceles- or equilateral-triangular, abruptly narrowed to a blunt apex, sometimes apiculate and dentate at the apex; margins involute near the apex, borders narrow above, clearly widened near the base; hyaline cells rhomboidal, often divided, usually fibrillose and porose in the upper cells. Branches often in fascicles of 5, with 3 spreading. Branch leaves 1.0–1.3 mm × 0.3–0.5 mm, clearly arranged in 5 rows, erect-spreading, ovate-lanceolate, cucullate-concave, blunt, dentate at the apex; margins bordered by 2–3 rows of linear cells, shiny when dry; hyaline cells fibrillose, with small, unringed pores at the corners, becoming larger near margins on the ventral surface, with half-elliptic, ringed pores at the opposite ends along commissural rows on the dorsal surface; green cells in cross section triangular or trapezoidal, exposed on the ventral surface. Monoicous; antheridial branches short, reddish, globose at the tips; perigonial leaves similar to the vegetative branch leaves. Perichaetial leaves large, broadly ovate, blunt at the apex, borders wide; hyaline cells divided, without fibrils and pores. Spores yellowish brown, smooth, 21–25 µm in diameter.

Type. Ireland.

Chinese specimens examined: SICHUAN: Bao-xing Co., G.-L. Qu 3425 (PE). YUNNAN: Gong-shan Co., between Nu-jiang (river) and Du-long-jiang (river), Handel-Mazzetti 9249 (H, KUN).

Habitat: usually in bogs or wetlands in shade under forests; Distribution: China, India, Japan, Europe, and North America.

Illustrations: C. Gao (ed.) 1994 (Pl. 15, figs. 13–15).