Sphagnum

Sporophytes are common in Sphagnum quinquefarium. This species is usually associated with S. capillifolium, S. girgensohnii, and S. russowii. No other species of sect. Acutifolia has the combination of quinquefarious branch leaves and three spreading branches per fascicle. Sphagnum rubiginosum has three spreading branches but the branch leaves are quite unranked and its lingulate stem leaf is quite distinct from the triangular stem leaf of S. quinquefarium. See also discussion under 86. S. talbotianum.

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.

Plants moderate-sized, typically stiff and compact, capitulum usually hemispherical; green, grayish white, pale yellow, purplish red, may have a slight metallic luster when dry. Stems pale green or yellowish, rarely red-tinged; superficial cortical cells mostly aporose, but some cells may have a single oval to elliptic pore-like wall thinning in the distal portion of the cell. Stem leaves triangular to triangular-lingulate, 1-1.3 mm, apex acute to slightly obtuse, border broad at base (more than 0.25 width); hyaline cells narrowly rhomboid, mostly 0-1-septate and mostly efibrillose. Branches usually strongly 5-ranked. Branch fascicles with mostly 3 spreading and 1-2 pendent branches. Branch leaves ovate to ovate-lanceolate, 1.1-1.5 mm, concave, straight, apex slightly involute; hyaline cells on convex surface with numerous oval to elliptic pores along commissures grading from small pores near apex to large round pores at base, concave surface with large round pores in proximal portions of leaf. Sexual condition monoicous or dioicous. Spores 19-27 µm, finely papillose on proximal surface, pusticulate on distal surface; proximal laesura less than 0.4 spore radius.

Distribution: China, India, Japan, Europe, and North America.

Habitat: usually in bogs or wetlands in shade under forests.

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

Sphagnum acutifolium var. quinquefarium Lindberg in R. Braithwaite, Sphagnac. Europe, 71. 1878; S. schofieldii H. A. Crum