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Atlantic sphagnum

sphagnum

Habit Plants robust and weak-stemmed; green, golden brown to dark brown; capitulum often flat-topped and with a visible terminal bud; flaccid and plumose in submerged forms to more compact in emergent or stranded forms. Plants small, soft, fairly weak-stemmed; pale green to pale yellow brown; capitulum not 5-radiate or only weakly so, may be tinged with red; loose to somewhat compact.
Stem(s)

leaves triangular, large, less than 1.7 mm, mostly appressed to stem, apex weakly apiculate to narrowly obtuse;

hyaline cells efibrillose and seldom to often septate at base and sides.

leaves 0.7–1 mm (to 1.2 mm in hemiisophyllous forms) elongate-triangular to triangular-lingulate, apex obtuse-erose, to apiculate; usually fibrillose at least apically; in hemiisophyllous forms spreading and in anisophyllous forms appressed;

hyaline cells often septate at base.

Branches

unranked, long and tapering, leaves greatly elongate at distal end.

moderately long and tapering, unranked to weakly 5-ranked, leaves not much elongated at distal end.

Branch leaves

ovate-lanceolate to lanceolate in aquatic forms, ovate to ovate-lanceolate in emergent forms, greater than 2.5 mm, often falcate-secund, especially in submerged forms, weakly undulate and recurved when dry;

margin entire, hyaline cells on convex surface with 0–1 pores per cell, concave surface with round wall thinnings in the cell apices and angles; chlorophyllous cells narrowly triangular in transverse section and well-enclosed on the concave surface.

1–1.7 mm, ovate-lanceolate, undulate and recurved when dry;

hyaline cells on convex surface with 3–10 round pores per cell in the cell angles and free, on concave surface with round wall thinnings in the ends and angles.

Sexual condition

dioicous.

unknown.

Spores

not seen.

Branch

fascicles with 2 spreading and 2 pendent branches.;

branch stem green, cortex enlarged with conspicuous retort cells.

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

branch stem cortex enlarged and with conspicuous retort cells.

Sporophytes

not seen.

Sphagnum atlanticum

Sphagnum rubroflexuosum

Habitat Forming loose carpets in pools in weakly minerotrophic fens Forming carpets in weakly minerotrophic fens
Elevation low elevations moderate elevations
Distribution
from FNA
CT; DE; MA; MD; ME; NC; NH; NJ; NY; PA; RI; VA; VT; NB; NF; NS
from FNA
MD; PA
Discussion

Sporophytes of Sphagnum atlanticum are rare. The other large North American Atlantic coastal plain species of sect. Cuspidata, S. torreyanum, is typically more yellow, has a more rounded capitulum, and has straight rather than subsecund branch leaves.

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

Sporophytes are unknown in Sphagnum rubroflexuosum. Compared to the closely related S. flexuosum, this species is paler and may have a reddish stem. Otherwise, identification must be made microscopically on the basis of branch leaf porosity. Although we have not seen this species in the field, it should be separable from S. majus, the only other large, aquatic species of sect. Cuspidata, in its range by traits of stem leaves and its color. Sphagnum majus is also typically a much darker brown.

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

Source FNA vol. 27, p. 65. FNA vol. 27, p. 76.
Parent taxa Sphagnaceae > Sphagnum > sect. Cuspidata Sphagnaceae > Sphagnum > sect. Cuspidata
Sibling taxa
S. affine, S. alaskense, S. andersonianum, S. angermanicum, S. angustifolium, S. annulatum, S. aongstroemii, S. arcticum, 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. squarrosum, 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
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. russowii, S. sitchense, S. splendens, S. squarrosum, 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
Name authority R. E. Andrus: Bryologist 110: 274, figs. (2007) R. E. Andrus: Bryologist 91: 364, figs. 1–8. (1988)
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