Pale Bog Moss

Though they seldom if ever overlap ecologically, Sphagnum strictum and S. squarrosum both usually have squarrose branch leaves, but S. squarrosum has a lingulate fringed stem leaf that differs greatly from the triangular and entire-margined stem leaf of S. strictum.

Plants moderate-sized, pale green, yellow-green to occasionally strongly reddish; growing in loose mats. Stems pale brown to green. Stem leaves very small, less than 0.8 mm, triangular with blunt rounded apex. Branches erect in distal portion of plants. Branch fascicles with 2 short-spreading and 3 long-tapering pendent branches. Branch leaves large, 2.8 mm or longer, sub-squarrose, ovate, involute to broad, truncate apex with more than 6 teeth; hyaline cells with up to 6 non-ringed pores on convex surface with few or no pseudopores, 2-4 elliptic ringed pores on concave surface in corners or along commissures, internal commissural walls minutely papillose (best viewed in oblique sections), rarely smooth; chlorophyllous cells narrowly triangular in transverse section, more broadly exposed on convex surface, enclosed on concave surface. Sexual condition monoicous. Capsule with abundant pseudostomata on surface of capsule. Spores 31-43 µm; coarsely papillose on both proximal and distal surfaces, raised Y-mark sculpture on distal surface; proximal laesura moderately long, 0.4-0.7 spore radius.

Sphagnum compactum var. expositum W. S. G. Maas; S. garberi Lesquereux & James; S. mexicanum Mitten

Sphagnum strictum SuU. Musci Alleph. 201. 1845
sphagnum humile Schimp.; Sull. in A. Gray, Man. ed. 2. 611. 1856. Sphagnum mexicanum Mitt. Jour. Linn. Soc. 12: 624. 1869. Sphagnum Garberi Lesq. & James. Proc. Am. Acad. 14: 133. 1879. Sphagnum domingense C. Miill. Hedwigia 37: 219. 1898. (Fide Wamst.)
Plants low and compact to rather tall and robust, straw-yellow or sometimes tinged with hght-green. Wood-cylinder yellowish-green; cortical cells of the stem in 1-3 layers, thinwalled, without fibrils, the outer cells quadrilateral, commonly longer than broad, without fKDres: stem-leaves small, triangular to lingulate-triangular, concave, with a border of narrow cells; hyaline cells not divided, without fibrils except in hemi-isophyllous forms, the membranepleats not prominent, if present confined to a few apical cells, on the inner surface an irregular membrane-gap in each cell, near the apex of the leaf occupying nearly the whole of the cell, the cell-walls of the border only slightly pitted: branches close, normally in fascicles of 5, 2 spreading, their cortical cells in a single layer, without fibril-bands, imiform, the upper end terminating in very short outwardly turned neck and pore: branch-leaves long-squarrose, ovate-lanceolate, involute above, truncate and toothed at the apex, the margin denticulate; hyaline cells fibrillose, elongate-rhomboidal, 4-8 times as long as wide, on the inner surface with strongly ringed elliptic pores in the corners of the cells, generally then in pairs or threes at adjacent angles, 2-4 per cell, on the outer surface with more numerous pores in the vicinity of the commissures, strongly ringed, 5-15 per cell, sometimes less numerous, 1-4 per cell, pseudopores lacking: chlorophyl-cells in section rounded-triangular, enclosed on the inner surface of the leaf, exposed with a thick wall on the outer surface, the lumen large, lenticular; inner walls of hyahne cells where overlying chlorophyl-cells minutely papillose or rarely smooth; hyaline cells very slightly convex on the outer surface, much more so on the inner where up to one third of the diameter of the cell.
Dioicous so far as obsers-ed and not commonly fruiting. Antheridia on undifferentiated branches. Fruiting branches short; perichaetial leaves few, more or less secund, ovatelanceolate, strongly involute, obtuse to irregularly truncate at the apex, the hyaline cells fibrillose except in the basal part, border, and apex, where they are narrow-linear and generally show a single round membrane-gap on the inner surface, the fibrillose cells with numerous pores along the commissures on the inner surface, on the outer surface with only occasional end-pores; outer border of 2-3 rows of narrow cells lacking a resorption-furrow : capsule small, brown: spores greenish-yellow, 35-45 ^ in diameter, smooth or somewhat granular-roughened.
Type locality: " Devil's Court House," North Carolina.
Distribution: Newfoundland southward to Florida, Alabama, and Mexico; reported from Labrador and the West Indies; also in Norway.