Sphagnum

This is a common species in northeastern and southwestern China. It is characterized by having rather robust and jade green plants that frequently produce sporophytes and by having large and squarrose branch leaves.

In its typical robust form with strongly squarrose branch leaves, Sphagnum squarrosum is unmistakeable. Smaller forms such as occur in the higher mountains may be difficult to identify accurately without careful examination of microscopic details. In the tundra there sometimes occur large, terete forms of S. squarrosum but these are usually considerably more robust than S. teres. See also discussion under 14. S. strictum.

Plants rather robust, jade green to yellowish green or yellowish brown, in loose tufts. Stem cortex in 2–4 layers, hyaline cells thin-walled, without fibrils, sometimes with large pores; central cylinder pale green or yellowish orange. Stem leaves 1.6–1.7 mm × 1.0–1.4 mm, large, ligulate, rounded obtuse, somewhat lacerate at the apex; borders narrow, indistinct; hyaline cells in the upper half broadly rhomboidal, often undivided, without fibrils and pores, sometimes divided, cells in the lower half narrowly rhomboidal, sometimes with the traces of fibrils, with large pores. Branches in fascicles of 4–5, with 2–3 spreading, stout. Branch leaves 2.0–2.3 mm × 1.0–1.2 mm, broadly ovate-lanceolate, concave, strongly squarrose and gradually narrowed to an involute-concave acumen from an erect base; margins involute, blunt and dentate at the apex; hyaline cells densely fibrillose, with small, ringed pores in the upper cells, half-elliptic pores at the opposite ends in the lower cells on the ventral surface, with a few pores at the upper corners in the upper cells, more and more pores at the opposite ends in the lower half on the dorsal surface; inner walls adjacent to green cells sometimes faintly papillose; green cells in cross section triangular to trapezoidal, exposed more broadly on the dorsal surface, also slightly exposed on the ventral surface. Dioicous; antheridial branches green; archegonial branches elongate. Perigonial leaves smaller than vegetative branch leaves. Perichaetia leaves large, broadly ligulate, concave. Spores yellowish, papillose, 22–25 µm in diameter.

Plants robust, stiff; green, pale green, yellow-green; large terminal bud; typically as loose carpets in coniferous forests. Stem green to red-brown; 2-3 superficial cortical layers. Stem leaves shorter than branch leaves, ovate-lingulate to oblong-lingulate, 1.6-1.8 × 1-1.2 mm; hyaline cells mostly nonseptate. Branches long and tapering with distinct squarrose spreading leaves, often terete in tundra forms. Branch fascicles with 2 spreading and 2-3 pendent branches. Branch stems with 1-2 layers of cortical cells. Branch leaves larger than stem leaves, 1.9-2.8 mm, conspicuously squarrose from ovate-hastate base and abruptly narrowed ¹/2-¹/3 distance from apex into involute-concave acumen, often terete in tundra forms; hyaline cells convex on both surfaces, non-ringed pores at ends and corners of cells, ringed pores on concave surface (4-8/cell) and nonringed pores (2-4/cell) on convex surface, internal commissural walls smooth or indistinctly papillose, chlorophyllous cells ovate triangular with widest part at or close to the convex surface. Sexual condition monoicous. Spores 17-30 µm; proximal surface finely papillose, distal surface smooth with raised bifurcated Y-mark sculpture; proximal laesura more than 0.5 spore radius.

Distribution: China, India, Korea, Japan, Central Asia, Europe, Greenland, North America, New Zealand, and North Africa.

Habitat: in seasonally flooded areas or on wet soil under conifers; sometimes on rotten wood in shade.

Sphagnum cymbifolium var. squarrosum (Crome) Nees & Hornsch., Bryol. Germ. 1: 11. 1823. Sphagnum teres var. squarrosum (Crome) Warnst., Eur. Torfm. 121. 1881, nom. illeg. Sphagnum squarrosum var. subsquarrosum Russ. ex Warnst., Hedwigia 27: 271. 1888.

Sphagnum squarrosum var. imbricatum Schimper

Sphagnum squarrosum Crome, Samml. Dents Laubm. 24. 1803.
Plants generally tall and very robust, bright-green or sometimes yellowish. Woodcylinder green to reddish-brown; cortical cells of the stem in 2-3 layers, of irregular size and shape, with thin walls, the outer cells narrowly quadrilateral, much longer than broad, without fibrils or pores: stem-leaves large, long ovate-lingulate, slightly concave, the apex weakly lacerate-fimbriate, passing into a suggestion of a hyaline border and this into an indistinct border of narrow cells extending to the base; hyaline cells in the apical portion rhomboidal, short, not more than 2-3 times as long as wide, in basal side-regions of the same length but narrow^er, mostly undivided and without fibrils, the membrane on the outer surface almost completely resorbed, on the inner surface the membrane-gaps confined to cells of the immediate apex, the membrane otherwise entire, frequently with longitudinal membrane-pleats: branches often very long, in fascicles of 5, 2 spreading, their cortical cells in a single or double layer, without fibrils, the retort-cells slightly differentiated with inconspicuous neck: branch-leaves strongly squarrose from the center, sometimes spreading or nearly imbricate, large, ovatehastate, broadening rapidly from the base, then suddenly contracting to an acute, involute, toothed apex, the border entire, of 2-3 rows of long narrow cells; hyaline cells strongly fibrillose throughout, narrowly rhomboidal, 4—8 times as long as wide, shorter toward the ai>ex and much broader in the middle side-regions, on the inner surface with rather numerous round pores in the ends of the cells and near the commissures, 4-10 per cell, except in the middle basal portion where they are lacking, most numerous and largest in large cells of the middle side-regions, on the outer surface less numerous, in the ends and corners of the cells, generally 1-3 per cell, except in the middle basal portion where they are large and numerous in a single or double row, sometimes 10 or more per cell, with pseudopores also in apical cells; chlorophyl-cells in section triangular with the base exposed on the outer surface or trapezoidal with a narrow exposure also on the inner surface; inner walls of the hyaline cells where overlying the chlorophyl-cells often strongly papillose; hyaline cells convex on both surfaces, on the outer only slightly, one sixth or one fifth, on the inner rather more, one fourth or one third of the diameter of the cell.
Monoicous. Antheridial catkins conspicuous; antheridial leaves often deeply pigmented, brown, spreading, ovate, strongly involute, smaller than the normal branch-leaves, the fibrils in cells of basal region weak or lacking. Fruiting branches erect, long; perichaetial leaves long-lingulate, strongly involute, the apex truncate or retuse, fimbriate, their texture as in the stem-leaves; hyaline cells on the outer surface with large membrane-gaps, on the inner surface entire with longitudinal membrane-pleats: capsule brown: spores brownish-yellow, 20-25 m in diameter, papillose.
Type locality: Europe.
Distribution: Greenland and Labrador southward to New Jersey; Pennsylvania; Ohio; Michigan: Wisconsin; Minnesota ; Colorado; California northward to Alaska and adjacent islands; also in Europe and Asia.

Sphagnum squarrosum, commonly known as the spiky bog-moss or spreading-leaved bog moss is a species of moss which grows in nutrient-rich, damp soil. Typical habitats include woodland, the banks of streams and ditches; it can even be found at high altitude in damp cirques. The species often grows near sedges (Carex), rushes (Juncus) or purple moor grass (Molinia caerulea).

Sphagnum squarrosum plants are green, and have the appearance of spikiness.