Sphagnum

Shade forms of Sphagnum teres are often squarrose but these are usually considerably smaller than S. squarrosum. For other distinctions between these species, see discussion under the latter.

Plants rather slender, yellowish green or brown, in loose carpets. Stem cortex in 3–4 layers, hyaline cells thin-walled, without fibrils or pores, sometimes with a single pore, without fibrils; central cylinder yellowish or reddish brown. Stem leaves 1.3–1.4 mm × ca. 1 mm, ligulate, rounded obtuse, dentate or lacerate at the apex; borders hyaline, cells indistinctly differentiated; hyaline cells usually undivided, without fibrils and pores, or rarely with the traces of fibrils and membrane gaps. Branches in fascicles of 5, with 2–3 spreading. Branch leaves 1.2–1.6 mm × 0.6–1.0 mm, ovate-lanceolate, gradually narrowed to a sharp acumen, reflexed in the upper part, margins involute; hyaline cells rhomboidal, fibrillose, with large, ringed pores at the corners of upper cells, gradually positioned along commissural rows in the lower cells on the ventral surface; with a few large, non-ringed pores at the upper corners, gradually becoming numerous rounded, ringed pores near the base on the dorsal surface; inner walls adjacent to green cells often faintly papillose; green cells in cross section trapezoidal, exposed more broadly on the dorsal surface, slightly exposed or largely enclosed by hyaline cells on the ventral surface. Dioicous. Perigonial leaves similar to vegetative branch leaves. Perichaetial leaves oblong-ligulate, 4.0–5.0 mm × 2.0 mm. Spores grayish brown, papillose, ca. 25 µm in diameter.

Plants fairly slender to moderate-sized, pale green to yellowish, or reddish brown in sun-grown forms; forms loose to dense carpets. Stems pale green to red-brown; 3-4 layers of superficial cells. Stem leaves generally larger than branch leaves, 1.3- 1.8 × 0.8-1 mm; elliptic to lingulate-spatulate, widest above middle, hyaline cells nonseptate. Branches long-cylindrical, branch leaves terete to sometimes distinctly squarrose in shade forms. Branch fascicles typically with 3 spreading (sometimes 2) and 2 pendent branches. Branch stems with single layer of cortical cells. Branch leaves 1-1.4 mm, ovate to ovate-lanceolate, gradually narrowed to an involute tip, hyaline cells somewhat bulging on concave surface and nearly plane on convex surface, with 4-8 large, elliptic, unringed pores per cell on convex surface and 1-4 irregularly rounded pores per cell on concave surface, internal commissural walls smooth to rather strongly papillose, chlorophyllous cells ovate-triangular with the widest part at or close to the convex surface. Sexual condition dioicous. Spores 21-26 µm; proximal and distal surfaces smooth, papillae indistinct; proximal laesura 0.5-0.6 spore radius.

Distribution: China, India, Japan, Russia (Siberia and Caucasus), Europe, Greenland, and North America.

Habitat: on humic soil under forests; also in bogs, at the margins of forests or near streams.

Sphagnum squarrosum ssp. teres (Schimp.) Ångstr. in C. Hartm., Handb. Skand. Fl. (ed. 8), 417. 1861.

Sphagnum squarrosum var. teres Schimper, Vers. Entw.-Gesch. Torfm., 64. 1858; S. teres var. squarrosulum (Schimper) Warnstorf