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rough peat moss, shaggy peat, sphagnum, spiky bog-moss, spread-leaf peat moss, spreading-leaf bog moss

Habit Plants robust, stiff; green, pale green, yellow-green; large terminal bud; typically as loose carpets in coniferous forests. Plants with branches in fascicles, branches usually of spreading and pendent types but rarely spreading only.
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.

Leaves

usually of two distinctly different types;

branch leaves that are normally inrolled and broadest ca. 1/4–1/3 the distance from the base, more or less tapered to a cucullate to involute apex;

stem leaves more or less flat and usually broadest at the base;

both leaf types of a network of hyaline, dead cells and green chlorophyllose cells;

pores and reinforcing fibrils frequent in branch leaf hyaline cells and uncommon in stem leaf hyaline 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.

released by explosive opening of operculum.

Branch

fascicles with 2 spreading and 2–3 pendent branches.;

branch stems with 1–2 layers of cortical cells.

Protonemata

thallose.

Rhizoids

lacking.

Sporophytes

consisting of a spherical capsule with pseudostomata on capsule surface, a very short seta, and a foot, exserted on a pseudopodium of gametophyte tissue.

Sphagnum squarrosum

Sphagnaceae

Phenology Sporophytes abundant, capsules mature early to mid summer.
Habitat Forming loose carpets in rich habitats such as wet coniferous forests, Thuja swamps, karrs, medium fens, and stream margins
Elevation low to high elevations
Distribution
from FNA
AK; AZ; CA; CO; CT; IA; ID; IL; IN; MA; ME; MI; MN; MT; NC; NH; NJ; NY; OR; PA; SD; TN; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; NT; NU; ON; PE; QC; SK; YT; Greenland; Eurasia; Pacific Islands (New Zealand)
[WildflowerSearch map]
Nearly worldwide
Discussion

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.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

The sphagnum mosses, or peat mosses, are unique not only morphologically but also ecologically. With their abundant clear cells they can retain up to 25 times their dry weight in water, and a uniquely strong acidifying power permits sphagnum to direct succession wherever conditions are suitable for them to flourish. Much of the earth’s surface with a cool humid climate is dominated, thus, by sphagnum peatlands.

Genus 1, species ca. 285 (89 species in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 27, p. 59. FNA vol. 27, p. 45. Authors: Cyrus B. McQueen†, Richard E. Andrus.
Parent taxa Sphagnaceae > Sphagnum > sect. Squarrosa
Sibling taxa
S. affine, S. alaskense, S. andersonianum, S. angermanicum, S. angustifolium, S. annulatum, S. aongstroemii, S. arcticum, S. atlanticum, S. austinii, S. balticum, S. bartlettianum, S. beothuk, S. bergianum, S. brevifolium, S. capillifolium, S. carolinianum, S. centrale, S. compactum, S. contortum, S. cribrosum, S. cuspidatum, S. cyclophyllum, S. fallax, S. fimbriatum, S. fitzgeraldii, S. flavicomans, S. flexuosum, S. fuscum, S. girgensohnii, S. henryense, S. imbricatum, S. inexspectatum, S. inundatum, S. isoviitae, S. jensenii, S. junghuhnianum, S. kenaiense, S. lenense, S. lescurii, S. lindbergii, S. macrophyllum, S. magellanicum, S. majus, S. mcqueenii, S. mendocinum, S. microcarpum, S. mirum, S. mississippiense, S. molle, S. obtusum, S. oregonense, S. orientale, S. pacificum, S. palustre, S. papillosum, S. perfoliatum, S. perichaetiale, S. platyphyllum, S. portoricense, S. pulchrum, S. pylaesii, S. quinquefarium, S. recurvum, S. riparium, S. rubellum, S. rubiginosum, S. rubroflexuosum, S. russowii, S. sitchense, S. splendens, S. steerei, S. strictum, S. subfulvum, S. subnitens, S. subsecundum, S. subtile, S. talbotianum, S. tenellum, S. tenerum, S. teres, S. torreyanum, S. trinitense, S. tundrae, S. viride, S. warnstorfii, S. wilfii, S. wulfianum
Subordinate taxa
Synonyms S. squarrosum var. imbricatum
Name authority Crome: Samml. Deut. Laubm., 24. (1803) Dumortier
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