BFNA Title: Sphagnaceae
Author: C. B. McQueen & R. E. Andrus 
Date: December 23, 2003
Edit Level: S
Version: 2 September 5, 2006

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden
BFNA Web site: http://www.mobot.org/plantscience/BFNA/bfnamenu.htm

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2.  SPHAGNACEAE   Dumortier

Cyrus B. McQueen

Richard E. Andrus

Plants with branches in fascicles, branches usually of spreading and pendent types but rarely spreading only.  Protonemata thallose.  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.  Rhizoids lacking.  Sporophyte consisting of a spherical capsule with pseudostomata on capsule surface, a very short seta, and a foot, exserted on a pseudopodium of gametophyte tissue.  Spores released by explosive opening of operculum.

The sphagnum mosses, or peat mosses, are not only unique morphologically but also ecologically.  With their abundant clear cells they can retain up to 25 times their dry weight in water, and a uniquely powerful 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): nearly worldwide.

 

1.  SPHAGNUM   Linnaeus, Sp. Pl. 2: 1106.  1753   *   [Greek sphagnos, an unknown plant]

Plants typically with upright stems, young branches arranged spirally around stem at growing apex into a capitulum, branches clustered into fascicles along stem, stem and branch leaves of alternating inflated, S-shaped to rhomboid hyaline cells and narrow linear chlorophyllous cells, hyaline cells typically fibrillose and porose on branch leaves.  Protonema typically 1-stratose, gametophyte developing from lateral margin.  Stems differentiated into a central cylinder of thin-walled parenchymatous cells, merging into a cylinder of thick-walled cortical cells surrounded by 0--4 layers of thin-walled inflated cells, superficial layer of cells usually aporose, but may be porose.  Stem leaves may be less fibrillose or efibrillose and less porose or aporose than the branch leaves, often septate, a distinct border of narrow linear chlorophyllous cells often along margins and at base, and with a greater width:length ratio than branch leaves in anisophyllous forms, partly differentiated in hemiisophyllous forms, and identical in isophyllous forms.  Branches typically dimorphic as spreading and pendent branches, but some species lack branches or branches are not clearly differentiated, pendent branches typically more slender than spreading branches and with a tendency to adhere to and cover the stem.  Branch fascicles typically with 2 spreading and 1--2 pendent branches, but there may be up to 12(--14) per fascicle.  Branch stems typically green, with a superficial layer of inflated retort cells; these grouped or solitary, usually porose at the distal end with a conspicuous or inconspicuous neck.  Branch leaves with 2/5 phyllotaxy, of a 1-stratose network of alternating chlorophyllous and hyaline cells; hyaline cells usually S-shaped, rarely rhomboid, nearly always strengthened with conspicuous spiral fibrils, small to large, round to elliptic and sometimes ringed pores occur along commissures or rarely on cell lumen, convex surface typically with more pores per cell than concave surface; chlorophyllous cells may be enclosed on both surfaces, more broadly exposed on one surface or equally exposed on both surfaces as viewed in transverse section, adjacent cell walls typically smooth, but various types of cell wall projections may be clearly visible in transverse section.  Sexual condition dioicous or monoicous; stalked globose antheridia borne at the tips of branches usually with swollen colored tips of branches near capitulum; long-necked archegonia borne on short branches singly surrounded by perichaetial leaves that are typically longer than branch leaves.  Capsule spherical, brown to black, lacking an annulus or peristome with a operculum convex; spore sac amphithecial in origin, over-arching columella.  Calyptra membranous.  Spores tetrahedral, with prominent trilete mark, fine to coarse superficial surface, distal surface may have raised Y-mark, bifurcated Y-mark sculpture, or none.

Species 250 (89 in the flora); primarily in boreal regions but also in cool, moist montane and oceanic habitats such as nutrient-poor and acidic wetlands and mires; worldwide in distribution excepting Antarctica.

The concept of species in the genus is controversial.  We have followed the lead of P. Isoviita (1966) and K. I. Flatberg (1994) in the recognition of species.  H. A. Crum (1984) and others (R. E. Daniels and A. Eddy 1985; A. L. Andrews 1958, 1959) have adopted more conservative taxonomic species concepts for species in the Northern Hemisphere.  Discussion of the spores above is from T. Cao and D. H. Vitt (1986); for additional discussion of the protonema see C. McQueen (1988).

Microscopic features can be observed by using a concentrated aqueous or alcohol solution of Crystal Violet.  A 50% solution of alcohol and Methylene Blue or Safranin Red can be used, but these usually do not stain features such as minute pores, fibrils, wall thinnings, and surface sculpture on the chlorophyllous cells.  The number and kinds of branches should be determined, individual stem and branch leaves (from the middle of a spreading branch) should be examined from the distal 2 cm of the plant, and the superficial surface of stem cortical cells may need examination as well as do cross sections of branch leaves and stems.

 

SELECTED REFERENCES   Andrus, R. E.  1980.  Sphagnaceae (Peat Moss Family) of New York State.  New York State Mus. Bull. 442.   Crum, H. A.  1984.  Sphagnopsida, Sphagnaceae.  North American flora, Series II, Part 11.  New York Botanical Garden, Bronx, New York.   Daniels, R. E. and A. Eddy.  1990.  Handbook of European Sphagna.  Institute of Terrestrial Ecology, Huntingdon.   Flatberg, K. I.  2002.  The Norwegian Sphagna: A field colour guide.  NTNU Vitenskapsmuseet Rapp. Bot. Ser.  2002--1: 1--44 + 54 plates.   Isoviita, P.  1966.  Studies on Sphagnum L.  1. Nomenclatural revision of the European taxa.  Ann. Bot. Fennici 3: 199--264.   McQueen, C. B.  1990.  Field Guide to the peat mosses of Boreal North America.  London.   Nyholm, E.  1969.  Illustrated moss flora of Fennoscandia II.  Musci 6: 647--799.  Lund.

 

1.   Outer stem cortical cell walls reinforced with spiral fibrils
................................................. 1a.   Sphagnum sect. Sphagnum, p. XXX

1.   Outer stem cortical cell walls smooth.

2.   Outer cortical cells of branches nearly all porose at distal end; branch leaves with denticulate margins and bordered with resorption furrow
................................................... 1b   Sphagnum sect. Rigida, p. XXX

2.   Outer cortical cells of branches of two kinds, smaller aporose cells and larger retort-shaped cells with pore at apical end; branch leaf margins usually entire.

3.   Fascicles of 7 or more branches 1h.   Sphagnum sect. Polyclada, p. XXX

3.   Fascicles of 6 or fewer branches.

4.   Branch leaf hyaline cells efibrillose, but see  S. splendens in sect. Cuspidata
................................. 1e.   Sphagnum sect. Isocladus, p. XXX

4.   Branch leaf hyaline cells fibrillose.

5.   Branch and stem leaves isophyllous; branches in fascicles of 2--3, spreading and pendent branches similar, or plants may have single or no branches; hyaline cells of branch leaves usually with numerous pores along the commissures, giving a bead-like appearance; chlorophyllous cells of branch leaves in transverse section barrel-shaped, truncate-elliptic to trapezoidal, exposed equally on both surfaces or slightly more broader on the convex surface
.......... 1g.   Sphagnum sect. Subsecunda, p. XXX (in part)

5.   Branch and stem leaves usually anisophyllous; 3--6 branches per fascicle, spreading branches clearly differentiated from pendent branches; hyaline cells of branch leaves with scattered pores along the commissures; chlorophyllous cells of branch leaves in transverse section triangular, truncate-trapezoidal to elliptical and may be more broadly exposed on either surface.

6.   Branch leaf chlorophyllous cells triangular to trapezoidal, exposed much more broadly on concave or convex surface

7.   Chlorophyllous cells of branch leaves triangular to trapezoidal in transverse section, more broadly exposed on the convex surface; in plants with stellate capitula, the branches between the rays of the capitulum occur in pairs; stem leaves often hanging downward on the stem
.............. 1f.   Sphagnum sect. Cuspidata, p. XXX

7.   Chlorophyllous cells of branch leaves triangular to trapezoidal in transverse section, more broadly exposed on the concave surface; in plants with stellate capitula, the branches between the rays of the capitulum single; stem leaves upright on the stem............... 1i.   Sphagnum sect. Acutifolia, p. XXX

6. Branch leaf chlorophyllous cells lenticular, truncate-elliptic to trapezoidal; exposed more or less equally on both surfaces or slightly more broadly on convex surface.

8.   Stem leaves with apex broad and fimbriate; branch leaves often squarrose from an enlarged clasping base; interior surface of chlorophyllous cells often finely papillose. 1d.   Sphagnum sect. Squarrosa, p. XXX

8.   Stem leaves with apex obtuse and entire to erose; branch leaves straight, slightly subsecund, or slightly recurved; interior surface of chlorophyllous cells always smooth.

9.   Branch leaves with broad truncate toothed apex, hyaline cells with pores in cell ends and angles
........... 1c.   Sphagnum sect. Insulosa, p. XXX

9.   Branch leaves with rounded, untoothed or weakly toothed apex, hyaline cells on convex surface with numerous pores along commissures
1g.   Sphagnum sect. Subsecunda, p. XXX (in part)

 

1a.  Sphagnum   Linnaeus sect.  Sphagnum

Plants typically large, with distinct capitulum; green, pale green, yellowish, red, tan, brown to dark brown.  Stems green, brown or reddish, outer cortex of 3--4 layers of inflated, thin-walled cells, superficial cells with conspicuous to faint spiral fibrils, no or strong ornamention on interior wall, and 1--6 round to ovate pores per cell.  Stem leaves typically as large as or larger than branch leaves, lingulate to ovate-lingulate with broad rounded apex, border fringed; hyaline cells rhomboid, efibrillose or fibrillose, sometimes ornamented, aporose, 0--2-septate, and often resorbed on exterior surface.  Branches dimorphic, spreading branches tumid, pendent branches usually shorter and more slender.  Branch fascicles with 2--3 spreading branches and 1--3 pendent branches.  Branch stems green, surrounded by 1 layer of enlarged thin-walled cells, typically porose and fibrillose, in some species ornamented on interior wall; retort cells absent.  Branch leaves ovate to broadly ovate, apex cucullate and roughened on convex surface; margin toothed; hyaline cells fibrillose; convex surface pores round to elliptic, usually with 1 at each corner of three adjacent hyaline cells; chlorophyllous cells lenticular to triangular, sometimes with wall ornamentation visible in transverse section; chlorophyllous cells enclosed, equally exposed, or more broadly exposed on concave surface, end walls thickened or onthickened.  Sexual condition usually dioicous.  Capsule 2 mm or more.  Spores typically 22--30 \um, distal surface sculpture may be present; proximal laesura usually more than 0.5 spore radius.

Species 54 (12 in the flora): worldwide in distribution excepting Antarctica.

 

1.   Branch leaf chlorophyllous cells in transverse section more or less equilateral-triangular, often with conspicuous vertically oriented comb-fibrils on the hyaline cells where overlying chlorophyllous cells.

2.   Branch cortical cells with funnel-like projections often extending halfway or more into the next cell; branches strongly clavate and blunt
.............................................................. 11.   Sphagnum portoricense

2.   Branch cortical cells with flat end walls or with weak funnel-like projections extending less than halfway into the next cell; branches not clavate or if clavate, with pointed ends.

3.   Interior layer of stem cortical cells with distinct comb-lamellae; branch leaves with or without comb-lamellae; stem leaves without comb-lamellae............................................... 1.   Sphagnum affine

3.   Interior layer of stem cortical cells without comb-lamellae or at least not visible with a light microscope; branch leaves with comb-lamellae; stem leaves with or without comb-lamellae.

4.   Stem leaf hyaline cells with distinct comb-lamellae; branches clavate andpointed; branches leaves strongly imbricate
............................................................ 3.   Sphagnum austinii

4.   Stem leaf hyaline cells with distinct comb-lamellae; branches not clavate; branch leaves more or less spreading.

5.   Stem leaves short (ca. 0.8--1.1 mm); branch leaves broad (breadth:length ca. 0.7--0.8), branch leaf comb-lamellae usually distinct only in lower half of leaf; branch cortical comb-lamellae present; plants yellow to golden brown
................................................ 6.   Sphagnum imbricatum

5.   Stem leaves long (ca 1.1--1.5 mm.); branch leaves narrow (breadth:length ca. 0.6--0.68), branch leaf comb-lamellae distinct throughout most of leaf; branch cortical cell comb-lamellae usually absent; plants dark brown 12.   Sphagnum steerei

1.   Branch leaf chlorophyllous cells in transverse section narrowly triangular, trapezoidal, truncate-elliptic, elliptic or lenticular; comb-fibrils if present horizontally oriented.

6.   Branch leaf chlorophyllous cells in transverse section short elliptic, elliptic to lenticular, and enclosed on both surfaces.

7.   Branch leaf chlorophyllous cells in transverse section short-elliptic and well enclosed; plants purplish red when pigmented
........................................................ 7.   Sphagnum magellanicum

7.   Branch leaf chlorophyllous cells in transverse section narrowly elliptic and slightly enclosed on both surfaces; plants brown when pigmented.

8.   Branch leaf chlorphyllous cells in transverse section without thickened ends walls; superficial stem cortical cells with reinforcing fibrils weak or absent; branch leaf hyaline cells where overlying chlorophyll cells often with comb-fibrils
......................................................... 2.   Sphagnum alaskense

8.   Branch leaf chlorphyllous cells in transverse section with thickened end walls; superficial stem cortical cells with strong reinforcing fibrils; branch leaf hyaline cells where overlying chlorophyllous cells smooth.................. 4.   Sphagnum centrale

6.   Branch leaf chlorophyllous cells in transverse section narrowly triangular, rectangular to truncate-elliptic, exposed equally on both surfaces or more broadly on the convex surface.

9.   Branch leaf hyaline cells where overlying chlorophyllous cells papillose............................................... 9.   Sphagnum papillosum

9.   Branch leaf hyaline cells where overlying chlorophyllous cells epapillose.

10. Superficial stem cortical cells with fibrils weak or lacking; chlorophyllous cells rectangular to truncate-elliptic, exposed equally on both surfaces............ 10.   Sphagnum perichaetiale.

10. Superficial stem cortical cells with strong fibrils; chlorophyllous cells triangular exposed more broadly on concave surface.

11. Branch leaf hyaline cells where overlying chlorophyllous cells often with irregular worm-like ridges, especially at the leaf base; pores on the convex surface numerous, small and round to elliptic........................... 5.   Sphagnum henryense

11. Branch leaf hyaline cells smooth throughout; pores on the convex surface elliptic to flattened-elliptic, not numerous
..................................................... 8.   Sphagnum palustre

 

1.  Sphagnum affine   Renauld & Cardot, Rev. Bryol. 12: 44.  1885

Sphagnum imbricatum subsp. affine (Renauld & Cardot) Flatberg; S. imbricatum var. affine (Renauld & Cardot) Warnstorf; S. imbricatum var. laeve Warnstorf

Plants moderate-sized and lax to somewhat compact, +/- stiff-stemmed; moderate-sized to large, forming lawns or low, loose hummocks; green, yellow-brown to golden-brown and often tinged with brown to purplish brown; capitulum +/- flat in lax open-grown forms to +/- rounded and compact in open grown forms.  Stems brown, superficial cortical layer with spiral reinforcing fibrils clearly visible, usually 2 or more pores per cell, comb-fibrils visible on interior wall.  Stem leaves to 1.3--1.9 x 0.6--1.2 mm; rarely hemiisophyllous; hyaline cells non-ornamented, nonseptate or sometimes septate.  Branches +/- tapering, leaves loosely imbricate to spreading and often squarrose in shade forms.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems with cortical cell comb-lamellae weakly differentiated on interior wall, no or weak funnel-like projections on the interior end walls, pores in superficial wall mostly restricted to leaf attachments.  Branch leaves ovate to ovate elliptical, 1.5--2 x 0.9--1.6 mm; hyaline cells on convex surface with elliptic to more often round pores along the commissures, comb-lamellae can be present, but often absent or restricted to leaf bases; chlorophyllous cells broadly triangular in transverse section and well-enclosed on the convex surface; end wall not thickened.  Sexual condition dioicous.  Capsule with scattered pseudostomata .  Spores 27--31 \um; granulate on both surfaces; laesura on proximal surface less than 0.5 the spore radius.

Widespread and often ruderal, wide variety of minerotrophic wetlands, especially abundant in forested mires; Nfld. and Labr. (Nfld.), N.S., P.E.I.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio., Okla., Pa., S.C., Tenn., Tex., Vt., Va., W.Va.; Europe.

Capsules fairly common, mature early to late summer.  This species may occur elsewhere but the taxonomy is unclear (K. I. Flatberg 1984).  Although species of Sphagnum sect. Sphagnum are notoriously difficult to tell apart in the field, S. affine is typically smaller than S. centrale, S. palustre, and S. papillosum, the other brown species of this section with which it may occur.  It is also much more likely to have somewhat squarrose branch leaves, especially in shade forms.

 

2.  Sphagnum alaskense   R. E. Andrus & Janssens, Bryologist 106: 435, fig. 1, 3.  2003    E

Plants moderate-sized to robust, +/- weak-stemmed and compact, capitulum conspicuously large and flat-topped; pinkish brown to red-brown; compact low hummocks and hummock sides.  Stems brown, superficial cortical layer with spiral reinforcing fibrils lacking or faint, usually 2 or more pores per cell, comb-fibrils lacking on interior wall.  Stem leaves to 1.7 x 1.2 mm; rarely hemiisophyllous; hyaline cells nonseptate to occasionally septate, comb-lamellae absent.  Branches long and tapering.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the interior end walls, often with large round pores on the superficial wall.  Branch leaves broadly ovate, to 3 x 2.3 mm; hyaline cells on proximal half of convex surface with elliptical pores along the commissures, often with ridges running parallel to long leaf axis on hyaline cell surface overlying chlorophyllous cells; chlorophyllous cells elliptical and just enclosed on both surfaces in transverse section; end walls not thickened.  Sexual condition dioicous.  Capsule not seen.  Spores unknown.

Poor to medium fens and mineral edges of ombrotrophic mires; B.C.**c**; Alaska**c,AI,PH**, Wash.

Sphagnum alaskense most resembles S. magellanicum and S. centrale in its chorophyll cell cross-section.  The cross-section characteristic is most similar to that of S . centrale but S. alaskense lacks thickened walls.  Sphagnum alaskense also apparently does not have any range overlap with S. centrale, with the latter species being more of a boreal forest species.  Sphagnum alaskense occurs in more open and less mineral rich sites near the coast.  Sphagnum magellanicum has more well-enclosed chlorophyll cells and usually has some purplish coloration color, whereas S. alaskense often has a quite distinctive pinkish brown color which, along with its often large flattened capitula, can give it a distinctive look in the field.

 

3.  Sphagnum austinii   Sullivant in C. F. Austin, Musci Appal. 1: 3.  1870    F

Sphagnum cymbifolium subsp. austinii (Sullivant) J. Cardot; S. cymbifolium var. austinii (Sullivant) Warnstorf; S. imbricatum subsp. austinii (Sullivant) Flatberg

Plants moderate-sized to large, usually quite compact; reddish brown and often yellow flecked with red-brown; in dense stands forming large and tall hummocks.  Stems brown, superficial cortical cells with spiral reinforcing fibrils clearly visible , usually 2 or more pores per cell , comb-fibrils lacking on interior wall.  Stem leaves 1.2--1.6 x 1 mm; rarely hemiisophyllous; hyaline cells nonseptate or more typically mostly septate, comb-lamellae present on interior wall.  Branches clavate, tapering to short point, tightly imbricate at proximal end to somewhat spreading at distal end in less compact forms.  Branch fascicles with 2 spreading and 1 pendent branch.  Branch stems with cortical cell comb-lamellae visible on interior wall, conspicuous funnel-like projection on interior end walls extending to next cell less than one half its length, pores in superficial wall restricted to leaf bases.  Branch leaves ovate-elliptical to elliptical, 1.5--2.1 x 0.8--1.4 mm; hyaline cells on convex surface with numerous moderate-sized round pores along the commissures, comb-lamellae present throughout most of leaf; chlorophyllous cells broadly triangular in transverse section and well-enclosed on the convex surface, end wall not thickened.  Sexual condition dioicous.  Capsule with scattered pseudostomata.  Spores 23--28 \um; coarsely granulate on both surfaces; proximal laesura more than 0.50 spore radius.

Ombrotrophic mires and large hummocks in blanket mires; B.C.**c**, N.B., Nfld. and Labr. (Nfld.), N.S.; Alaska**PH**, Maine, Mass., N.J., Vt., Wash.; Europe.

Capsules common, mature mid-summer.  Sphagnum austinii is usually easily recognized in the field by its strongly imbricate and clavate branches.  It forms very dense and often tall hummocks with a distinct deep golden brown color.  In contrast to the view stated by H. A. Crum (1997), this species has an ecology and distribution quite distinct from S. affine.  Sphagnum affine is a minerotrophic species that does not even occur in the Pacific coast region, where S. austinii is quite prominent.

 

4.  Sphagnum centrale   C. E. O. Jensen in Arnell & C. E. O. Jensen, Bih. Sv. Vet.-Akad. Handl. 21, 3(10): 34.  1896

Sphagnum palustre subsp. intermedium Russow; S. subbicolor Hampe

Plants moderate-sized to robust, capitulum compact and well rounded in open grown forms, lax to somewhat compact; green in shade forms to golden yellow to golden brown in open-grown forms, occasionally with a pinkish tinge; lawns, loose low hummocks to larger, +/- firm hummocks.  Stems pale brown to brown, superficial cortical cells with spiral reinforcing fibrils clearly visible, 2 pores or more per cell, comb-fibrils lacking on interior wall.  Stem leaves to 1.2--2.2 x 0.8--1 mm; rarely hemiisophyllous: hyaline cells non-ornamented, rarely septate, comb-lamellae absent.  Branches tapering, leaves spreading to somewhat imbricate.  Branch fascicles with 2 spreading and 1--2 pendent branches.  Branch stems with cortical cells non-ornamented, no or weak funnel-like projections on the interior end walls, often with large round pores on the superficial walls.  Branch leaves broadly ovate, to 1.7 x 1.5 mm; hyaline cells non-ornamented, convex surface with elliptic to rarely round pores along the commissures; chlorophyllous cells lenticular to narrowly elliptical in transverse section, narrowly exposed on both ends, but more so on concave surface, end walls thickened at both ends.  Sexual condition dioicous.  Capsule with inconspicuous pseudostomata.  Spores 23--30 \um; surface finely roughened to smooth; laesura on proximal surface more than 0.50 spore radius.

Capsules uncommon, mature late summer.  Medium to rich fens, especially prominent in coniferous fens and sedge fens; Greenland**c**; Alta.**n**, B.C.**n**, Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Ont.**c**, P.E.I., Que.**c**, Sask.**n**; Conn., Idaho, Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Y., Ohio, Pa., Vt., Wash., Wis.; Eurasia.

Sphagnum centrale is most similar to S. alaskense but seems to have no range overlap and is also considerably more minerotrophic.  In the field it lacks the often reddish tinge of S. palustre and is larger then S. affine. See also discussion of 2. S. alaskense and 9. S. papillosum.

 

5.  Sphagnum henryense   Warnstorf, Hedwigia 39: 107.  1900

Sphagnum henryense var. bartlettii Warnstorf

Plants moderate-sized to robust, capitulum typically flat, +/- 5-radiate and with terminal bud slightly visible; green, pale green, to pale pinkish brown tinged with brown to reddish brown; forming carpets or low hummocks.  Stems pale green to brown; superficial cortical layer with spiral reinforcing fibrils clearly visible, usually 4 or more pores per cell, comb-fibrils lacking on onterior wall.  Stem leaves to 1.9 x 1 mm; rarely hemiisophyllous; hyaline cells non-ornamented, nonseptate or septate.  Branches +/- tapering to a point, leaves spreading to moderately imbricate.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems with hyaline cells non-ornamented; funnel-like projections absent from interior end walls, large round pores on superficial walls.  Branch leaves ovate, to 2.7 x 1 mm; hyaline cells on convex surface with numerous small round pores along the commissures, cell walls overlying chlorophyll cells often with a network of irregular worm like ridges although they may be lacking; chlorophyllous cells isosceles-triangular to narrowly ovate triangular in transverse section and just enclosed on convex surface,end wall not thickened.  Sexual condition dioicous.  Capsule with numerous pseudostomata .  Spores 24--29 \um; surface finely papillose to nearly smooth.

Poor to medium fens, common in wooded fens and pond margins; B.C.**c**, Nfld. and Labr. (Nfld.), N.S., P.E.I.; Ala., Alaska**PH**, Ark., Calif., Conn., Del., D.C., Fla., Ga., Ill., Ind., La., Maine, Md., Mass., Mich., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Oreg., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.; Asia (Japan?).

The typical form of Sphagnum henryense is a large plant with a quite flat capitulum with a small terminal bud.  Microscopically, typical material has distinct ridges on the branch leaf hyaline cells and relatively small and round pores on the branch leaf hyaline cell convex surface.  Sphagnum palustre, which has the same branch leaf chlorophyll cell cross section, typically has smooth hyaline cell walls and hyaline cell pores that are larger and more elliptical in shape.  However, Sphagnum species are plastic phenotypically and it is common to find plants that cannot be reliably assigned to either S. henryense or S. palustre.  For example, some species of Sphagnum that are relatively easy to distinguish on other characteristics, such as S. papillosum, S. alaskense and S. affine, may occasionally completely lack any hyaline cell ornamentation or display it in reduced form.  Since these can be distinguished on other characters, the species are still readily identifiable, but when S. henryense lacks the ornamentation, there is no other solid character to distinguish it from S. palustre.  Thus, although we can find material from both North American coasts that has good ornamentation (R. E. Andrus 1980), there is much other material that looks in other respects like S. henryense but lacks the ornamentation.  Barring taxonomy beyond microscopic examination, many collections of henryense/palustre will of necessity not be absolutely identifiable.  Where their ranges overlap, mixed stands may often be found.  We believe that the species are still good, but accurate delimitation of their distinctive ecologies and ranges will be very problematic.

 

6.  Sphagnum imbricatum   Russow, Beitr. Kenntn. Torfm. 99.  1865    E    F

Plants moderate-sized, weak-stemmed, lax; yellowish- to golden-brown; forming loose carpets; branches loosely imbricate.  Stems yellow to brown, superficial cortical layer with spiral reinforcing fibrils visible, 1 or more pores/cell, comb-fibrils on interior wall.  Stem leaves short-rectangular, 0.8--1.1mm, hyaline cells mostly non-septate and lacking comb-fibrils.  Branch fascicles with 2 spreading and 1--2 hanging branches.  Branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the end walls of cortical cells, cortical cell walls usually with large round pores.  Branch leaves ovate to ovate- elliptical, 1.4--1.8 mm; hyaline cells on convex surface with numerous pores along the commissures; comb-lamellae obvious only in lower 1/2 of leaf; chlorophyllous cells broadly triangular in transverse section and well-enclosed on the convex surface.  Sexual condition dioecious.  Spores (22) 24--27(--28) mu \um, surface granulate.

Ecology poorly known; Alaska**w**.

K. I. Flatberg’s (1984) revision of Sphagnum imbricatum considered this taxon to be East Asian in distribution but a recent collection in Selawik National Wildlife Refuge places it in the North American flora.  It will undoubtedly be found elsewhere.  Sphagnum imbricatum is closest in morphological detail to S. steerei, but S. steerei is a very dark colored and densely branched species whereas S. imbricatum is quite light in color and not particularly dense.

 

7.  Sphagnum magellanicum   Bridel, Musc. Recent. 2(1): 24.  1798

Plants moderate-sized to robust, somewhat lax in shade forms to quite compact and stiff in open grown forms; green to pinkish green to reddish purple; forms lawns in shaded habitats and low to moderately tall, dense hummocks in open habitats.  Stems green to purplish red, superficial cortical cells with spiral reinforcing fibrils clearly visible, usually 1 or 2 pores per cell, comb-fibrils lacking on interior wall.  Stem leaves to 2 x 0.7 mm; rarely hemiisophyllous; hyaline cells non-ornamented, mostly nonseptate.  Branches long and tapering to short and pointed, leaves loosely imbricate.  Branch fascicles with 2--3 spreading and 2--3 pendent branches.  Branch stems with hyaline cells non-ornamented; no or weak funnel-like projections on the interior end walls, large round pores on superficial cell wall.  Branch leaves broadly ovate, to 2 x 1 mm or more wide, broadly ovate, hyaline cells non-ornamented, convex surface with round to elliptic pores along the commissures; chlorophyllous cells short-elliptic in transverse section and well-enclosed on both surfaces.  Sexual condition dioicous.  Capsule with numerous pseudostomata.  Spores 22--30 \um; roughly papillose to nearly smooth, with distinct Y-mark sculpture on distal surface; proximal laesura 0.50--0.80 spore radius.

Capsules mature mid-summer.  Ecological amplitude very wide, ombrotrophic to rich fen peatlands, forested and open mires; Alta.**c**, B. C.**c**, Man.**c**, N.B., Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Ont.**c**, P.E.I., Que.**c**, Sask.**n**, Yukon **c**;  Ala., Alaska**c,AI,PH**, Ark., Calif., Conn., Del., Fla., Ga., Idaho, Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., S.C., Tenn., Tex., Vt., Va., Wash., W.Va., Wis.; South America; Eurasia.

As the only boreal species of Sphagnum sect. Sphagnum with a reddish purple color, S. magellanicum is usually easy to identify.  The branch leaf chlorophyll is capable of being confused only with S. alaskense, which is less enclosed on both surfaces, and S. centrale, and having thickened end walls on the chlorophyll cells that give them a narrow exposure on the concave surface.

 

8.  Sphagnum palustre   Linnaeus, Sp. Pl. 2: 1106.  1753

Sphagnum cymbifolium (Ehrhart) R. Hedwig

Plants moderate-sized to robust, strong-stemmed, lax to somewhat compact, capitulum somewhat flattened to more typically compact and rounded; green to golden brown to pale brown with often a pinkish tinge; carpets to more or less compact, low to moderate sized hummocks.  Stems brown, superficial cortical cells with spiral reinforcing fibrils visible, usually 2--4 pores per cell, comb-fibrils lacking on interior wall.  Stem leaves to 1.7 x 1 mm, occasionally longer; rarely hemiisophyllous; hyaline cells non-ornamented, nonseptate.  Branches long and tapering, leaves +/- imbricate to spreading in shade forms.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems with hyaline cells non-ornamented; no or weak funnel-like projections on the interior end walls, often with 1 large pore per cell on superficial cell walls.  Branch leaves broadly ovate, 2.2 x 1.3 mm, hyaline cells non-ornamented, convex surface with elliptic pores along the commissures, chlorophyllous cells isosceles-triangular to ovate-triangular in transverse section and just enclosed to just exposed on the convex surface; end wall not thickened.  Sexual condition dioicous.  Capsule with numerous pseudostomata.  Spores 24--33 \um, surface finely papillose to smooth, distal surface with distinct bifurcated Y-mark sculpture; proximal laesura more than 0.60 spore radius.

Capsules mature mid to late summer.  Widespread in forested fens and poor to rich sedge fens; B.C.**c**, N.B., Nfld. and Labr. (Nfld.), N.S., Ont.**s**, P.E.I., Que.**s**; Ala., Ark., Calif., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Oreg., Pa., S.C., Tenn., Tex., Vt., Va., Wash., W.Va., Wis.; Europe; Pacific Islands.

Sphagnum palustre may occur elsewhere than listed above, but the taxonomy is unclear.  In some open-grown situations, S. palustre may have a reddish tinge that may seem similar to S. magellanicum, but this is a pinkish red color rather than the purplish red of the latter.  See discussions of S. henryense and S. papillosum for distinction from those species.

 

9.  Sphagnum papillosum   Lindberg, Acta Soc. Sci. Fenn. 10: 280.  1872

Sphagnum cymbifolium var. papillosum Schimper; S. papillosum var. laeve Warnstorf; S. papillosum var. sublaeve Röll; Sphagnum waghornei Warnstorf

Plants moderate-sized to fairly robust; strong-stemmed and generally compact, capitulum usually not much enlarged; greenish brown to deep golden-brown; forming compact carpets in floating mats and depressions as well as dense stands on hummock sides and low hummocks.  Stems brown, superficial cortical layer with spiral reinforcing fibrils visible; usually 1--2 pores per cell, comb-fibrils lacking on interior wall.  Stem leaves to 1.3 x 0.7 mm; rarely hemiisophyllous; hyaline cells non-ornamented, mostly septate.  Branches generally short and blunt, leaves spreading.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the interior end walls, mostly with 1 pore per cell on superficial cell wall.  Branch leaves broadly ovate, 1.7 x 1 mm; hyaline cells on convex surface with round to elliptic pores along the commissures, hyaline cell walls covered with papillae where overlying chlorophyllous cells; chlorophyllous cells trapezoidal to truncate elliptic in transverse section, equally exposed on both surfaces or less exposed on convex surface, end walls thickened.  Sexual condition dioicous.  Capsule with numerous pseudostomata.  Spores 26--36\um; more roughly papillose on distal surface than proximal surface, distinct raised, bifurcated-Y mark sculpture on distal surface; proximal laesura 0.50 spore radius or more.

Capsules mature mid to late summer.  Very common in very poor to poor fen mire habitats where it is often a major peat former, but scarce to absent in truly ombrotrophic peatlands sites; B.C.**c**, N.B., Nfld. and Labr. (Nfld.), N.S, Ont.**c**, P.E.I., Que.**c**, Yukon, **s**; Alaska**c,AI,PH**, Calif., Conn., Del., Ill., Ind., Maine, Md., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., S.C., Vt., Wash., W.Va., Wis.; Eurasia.

Sphagnum papillosum is often easily field-identifiable by its rich golden-brown to dark brown color and short, blunt branches.  Nearly all specimens have the papillae on the branch leaf chorophyll cells but a few smooth forms have been found.  Such forms will have stem leaves with divided hyaline cells whereas in the confusable species S. palustre and S. centrale such cells are rare or absent.

 

10.  Sphagnum perichaetiale   Hampe, Linnaea 20: 66.  1847

Sphagnum brevicaule Warnstorf; S. cymbifolium var. ludovicianum Cardot; S. harperi Warnstorf; S. ludovicianum (Cardot) Warnstorf

Plants +/- moderate-sized, compact and stiff-stemmed; forming dense to somewhat loose low cushions in often seasonally dry depressions.  Stems brown; superficial cortical layer with spiral reinforcing fibrils faint to obvious, 1--3 pores per cell, comb-fibrils lacking on interior wall.  Stem leaves to 1.1 x 0.7 mm, commonly hemiisophyllous; hyaline cells non-ornamented, mostly 1--2-septate.  Branches short and blunt at distal end, leaves loosely spreading.  Branch fascicles with 2 spreading and 1--2 pendent branches.  Branch stems with hyaline cells non-ornamented, no or weak funnel-like projection of end walls of cortical cells, cortical cells with one large pore per cell on superficial wall.  Branch leaves ovate, to 2.2 x 1.1 mm; ovate, hyaline cells non-ornamented, on proximal half of convex surface with small ringed pores or pseudopores in groups of three where the corners join and pseudopores along the commissures; chlorophyllous cells narrowly rectangular, lenticular to narrowly trapezoidal in transverse section; exposed equally on both surfaces or more broadly on concave surface; end walls not thickened.  Sexual condition dioicous.  Capsule with numerous pseudostomata.  Spores 25--39 \um; surface smooth to irregularly and finely papillose; indistinct Y-mark on distal surface; proximal laesura more than 0.60 spore radius.

Capsules common, mature late spring to early summer.  Mostly ruderal, wet depressions in sandy substrates, often in areas recently burned, also low to moderate-sized hummocks in Chamaecyparis swamps; Ala., Del., Fla., Ga., La., Md., Miss., N.J., N.C., S.C., Tex., Va.; South America; se Asia; s Africa; Pacific Islands (New Zealand).

The compact growth form in thin but dense mats and occurrence in often dessication-prone sites distinguishes Sphagnum perichaetiale from any other species of section Sphagnum.  The often quite stiffly spreading branch leaves give it a strong resemblance to S. compactum, but S. compactum’s small triangular stem leaves will readily distinguish that.  The branch leaf hyaline cells of S. perichaetiale also have only a few pores on their convex surface, and these are typically small, thickened and grouped in 3s where the cell corners meet.  Similar species in sect. Sphagnum have more pores along the commissures, and these pores are more elliptical and not thickened.  The often hemiisophyllous stem leaves are also diagnostic of S. perichaetiale within sect. Sphagnum.

 

11.  Sphagnum portoricense   Hampe, Linnaea 25: 359.  1852

Sphagnum sullivantianum Austin

Plants moderate-sized to often quite robust, +/- weak-stemmed, lax; green, bluish green, green and brown to dark golden brown, often speckled in appearance; found submerged in shallow water, stranded along shore lines in loose carpets.  Stems brown, superficial cortical layer with spiral reinforcing fibrils clearly visible, usually many pores per cell (1--6), comb-fibrils on interior wall.  Stem leaves 1.1 x 1 mm; rarely hemiisophyllous; hyaline cells non-ornamented, frequently septate.  Branches clavate and rounded at distal end.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems with hyaline cell comb-lamellae visible on interior cortex wall, cortical cell end walls with conspicuous funnel projections more than 1/2 length of cell, superficial cortical wall aporose.  Branch leaves broadly ovate, 2.4 x 1.7 mm; hyaline cells on convex surface with numerous round pores along the commissures, comb-lamellae on hyaline cell walls where overlying chlorophyllous cells; chlorophyllous cells broadly triangular in transverse section and well-enclosed on the convex surface.  Sexual condition dioicous.  Capsule with pseudostomata.  Spores 22--29 \um; finely papillose on both surfaces; indistinct triradiate ridge on distal surface; proximal laesura 0.5--0.6 spore radius.

Stream channels, shallow ponds, coniferous and hardwood swamps and pocosins; Ala., Fla., La., N.J., N.Y., N.C., S.C., Tex.; Mexico; West Indies; South America.

Sphagnum portoricense is normally very easily distinguished because of its wet growing habit and strongly clavate branches.

 

12.  Sphagnum steerei   R. E. Andrus, Bryologist 90: 218.  1987    F

Sphagnum imbricatum var. arcticum Flatberg, Norske Vidensk. Selsk. Skr. 3: 46.  1984

Plants moderate-sized to large, compact and stiff-stemmed with upswept branches; dark green and brown, dark chesnut brown, brown to blackish brown, often with bluish tinge when dry; forming dense low to moderately tall hummocks.  Stems dark brown, superficial cortical layer with spiral reinforcing fibrils visible, usually 2 or more pores per cell, comb-fibrils lacking on interior wall.  Stem leaves to 1.2 x 0.8 mm; rarely hemiisophyllous; hyaline cells mostly nonseptate, comb-lamellae usually absent, but sometimes weak.  Branches short and blunt-tipped, leaves spreading.  Branch fascicles with 2 spreading and 1 pendent branch.  Branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the end walls of cortical cells, cortical cell walls usually with large round pores.  Branch leaves ovate to ovate-elliptical, 1.6--2.2 x 1 mm; hyaline cells on proximal half of convex surface with round to elliptic pores along the commissures; comb-lamellae on hyaline cell wall where overlying chlorophyllous cells; chlorophyllous cells broadly triangular in transverse section and well-enclosed on convex surface, end wall not thickened.  Sexual condition dioicous.  Capsule unknown.  Spores unknown.

Commonly in firm-bottomed poor to medium fen vegetation, subarctic to Arctic regions; Man.**n**, N.W.T.**c**, Nunavut**c**, Que.**n**, Yukon,**c**; Alaska**c**; e Asia.

Sphagnum steerei is usually easily recognized in the field by its dense growth habit and dark brown color.  Its ecology is somewhat unclear due to taxonomic confusion with S. imbricatum in the strict sense and S. austinii (R. E. Andrus 1987).  The latter is the only species in the imbricatum complex where S. steerei occurs.  Contrary to the view of H. A. Crum (1997), S. steerei is quite distinct from S. affine and S. austinii.  There is no range overlap with either of these species and the macroscopic appearance is also quite different.

 

1b.  Sphagnum   sect. Rigida   (Lindberg) Limpricht in G. L. Rabenhorst, Krypt. Fl. ed. 2, 4(1): 116.  1885

Sphagnum [unranked] Rigida Lindberg, Öfvers. Förh. Kongl. Svenska Vetensk.-Akad. 19: 135.  1862

Plants low-growing in loose mats to compact cushions, capitulum often indistinct or concealed by upwardly directed branches; pale green, straw-colored brownish to reddish.  Stems with superficial cortex of 1--3 layers of efibrillose, inflated, thin-walled, non-ornamented, and aporose cells.  Stem leaves much smaller than branch leaves, triangular-lingulate, border entire and broadened at base; hyaline cells rhomboid, efibrillose, nonornamented, aporose, and usually nonseptate; hyaline cells not resorbed on either, surface.  Branches strongly dimorphic, spreading branches much stronger than pendent branches.  Branch fascicles with 2--3 spreading branches and 2(--3) pendent branches.  Branch stems green, green to brownish, surrounded by 1 layer of efibrillose, non-ornamented, inflated, thin-walled, uniporse cells with slight protruding necks.  Branch leaves ovate to ovate-lanceolate, apex broadly truncate, smooth and toothed; margin denticulate; hyaline cells fibrillose, smooth or papillose, convex surface with +/- 5 small to medium-sized free pores, sometimes numerous pseudopores, concave surface with large pores in cell angles; chlorophyllous cells elliptic to ovate-triangular in transverse section, completely enclosed or exposed on concave surface, end walls unthickened.  Sexual condition monoicous or dioicous.  Capsule 2 mm or less, with numerous pseudostomata.  Spores mean diameter more than 30 \um, raised Y-mark sculpture on distal surface; proximal laesura more than 0.3 spore radius.

Species 5 (2 in the flora): worldwide in distribution excepting Antarctica.

1.   Chlorophyllous cells of branch leaves elliptic in transverse section and completely enclosed on both surfaces, adjacent hyaline cell walls smooth; stem leaves lingulate to oblong-triangular......... 13.   Sphagnum compactum

1.   Chlorophyllous cells of branch leaves elongate-triangular to ovate-triangular, enclosed on the adaxial surface and exposed on the convex surface, adjacent hyaline cell walls minutely papillose; stem leaves bluntly deltoid.. 14.   Sphagnum strictum

 

13.  Sphagnum compactum Lamarck & de Candolle, Fl. Fr. 2: 443. 1805

Sphagnum compactum var. imbricatum Warnstorf; S. rigidum (Nees & Hornschuch) Schimper

Plants moderate to large-sized, dense and compact, pale green, brownish white, golden brown to variegated golden-brown, can be reddish in rocky seep habitats; forms small, tufted compact cushions.  Stems brown.  Stem leaves small, 0.3--0.7 mm, triangular-lingulate with broad rounded apex,  Branches short, crowded, and unranked.  Branch fascicles 4--6 branches per fascicle, 2--3 spreading and 2--3 pendent, but plants frequently unbranched in young clones.  layer of cortical cells,  Branch leaves large, 1.4--3 mm, semi-squarrose to squarrose, ovate and abruptly involute in distal portion, appearing cucullate with toothed apex, usually no more than 6 teeth; hyaline cells with 5 or more ringed, round to elliptical pores on convex surface, numerous pseudopores on concave surface with 3 ringed corner pores occurring in 3’s at adjacent cell angles; chlorophyllous cells elliptic in transverse section, entirely included by hyaline cells, slightly nearer to convex surface.  Sexual condition monoicous.  Capsule with abundant pseudostomata.  Spores 25--35 \um; finely papillose on proximal surface, coarsely papillose on distal surface with raised Y-mark sculpture; proximal laesura short, 0.3--0.50 spore radius.

Capsules fairly common, mature summer.  Ombrotrophic to weakly minerotrophic, commonly growing on poorly drained sand, siliceous rocks, bare peat; Greenland**s**; Alta.**c**, B.C.**c**, Man.**c**, N.B., Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Ont.**c**, P.E.I., Que.**c**, Sask.**n**, Yukon**c**; Alaska**c,AI,PH**, Ark., Calif., Conn., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., S.C., Tenn., Vt., Va., Wash., W.Va., Wis.; South America; Eurasia; Pacific Islands (New Zealand).

Sphagnum compactum is usually easily recognized by its combination of golden brown color and involute, cucullate branch leaves.  Sphagnum strictum is paler and usually strongly squarrose.

 

14.  Sphagnum strictum Sullivant, Musci Allegh. 201.  1845

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

Plants moderate-sized, pale green, yellow-green to occassionally 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 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 \um; 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.

Capsules common, mature early- to mid-summer.  Pioneer species among grasses on peaty sand, pine barrens, burned-over savannas, seeps in mountainous areas inland; N.B., Nfld. and Labr. (Nfld.), N.S.; Ala., Fla., Ga., La., Maine, Md., N.J., N.C., S.C., Va.; Europe.

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.

 

1c.  Sphagnum   sect.  Insulosa   Isoviita, Ann. Bot. Fenn. 3: 231.  1966

Sphagnum [unranked] Truncata Horrell, J. Bot. 38: 119. 1900, not S. [unranked] Truncata Russow

Plants moderate-sized, with distinct capitulum; pale brownish yellow, yellow-green, loosely tufted.  Stems green, superficial cortex of 3--4 layers of efibrillose, inflated, thin-walled, non-ornamented cells , with an occasional pore in the distal end of the outer wall of the superficial cell layer.  Stem leaves smaller than branch leaves, oblong to lingulate, moderately lacerate across broad rounded apex, border entire and broad at base; hyaline cells rhomboid, aporose, non-ornamented, usually efibrillose, resorbed on distal portion of leaf with membrane pleats in proximal portion.  Branches dimorphic, the spreading branches stronger than the pendent branches.  Branch fascicles with 2--3 spreading and 2--3 pendent branches.  Branch stems green, surrounded by 1 layer of efibrillose, non-ornamented, inflated, thin-walled cells with inconspicuous necks.  Branch leaves broadly ovate, very concave, apex broadly truncate, smooth, and toothed; margin entire; hyaline cells non-ornamented, fibrillose; with elliptic, ringed pores at ends and corners of cells, usually found in 3’s at adjoining cell walls, pores more numerous on concave surface (5--8 per cell) than on convex surface (3--5 per cell); chlorophyllous cells in transverse section narrowly truncate-elliptic to lenticular, lacking wall sculptures, with thickened end walls equally exposed on both surfaces.  Sexual condition dioicous.  Capsule not seen.  Spores not seen.

Species 1: nw North America, Eurasia.

 

15.  Sphagnum aongstroemii   C. Hartman, Skand. Fl. ed. 7. 399.  1858

Sphagnum cymbifolium var. cordifolium C. Hartman, Skand. Fl. Ed.3. 261.  1838

Stems green.  Branch leaves very concave, truncate and toothed.

Wet rock faces and in moist depressions, usually in open among scattered shrubs and sedges in relatively minerotrophic sites.  B.C.**c**, N.W.T.**c**, Nunavut**c**, Yukon**c**; Alaska**cPH**; Eurasia.

Sphagnum aongstroemii can usually be easily recognized by combination of pale green color and its truncate, toothed branch leaves.

 

1d.  Sphagnum sect.  Squarrosa (Russow) Schimper, Syn. ed. 2. 835.  1876

Sphagnum [unranked] Squarrosa, Beitr. Torfm., 33.  1865

Plants moderate-sized to robust, with distinct capitulum; green,yellowish brown.  Stems green to dark reddish brown, superficial cortex of 2--4 layers of efibrillose, non-ornamented, enlarged, thin-walled, aporose, rectangular cells.  Stem leaves ovate, ovate-lingulate to lingulate; with broad, fringed apex; little or no border along margins or base; hyaline cells rhomboid, efibrillose, non-ornamented, aporose, usually nonseptate, with resorption gaps on exterior surface.  Branches strongly dimorphic, pendent branches thinner but about same length as spreading branches.  Branch stems green, with cortex surrounded by 1--2 layers of efibrillose, non-ornamented, enlarged, thin-walled cells, some cells apically porose with inconspicuous necks.  Branch leaves strongly squarrose or spreading, ovate, ovate-hastate or ovate-lanceolate, margins entire, apex involute and smooth; hyaline cells fibrillose; with large, round pores at cell ends and along commissures, sometimes with faint papillae on interior walls; chlorophyllous cells ovate-triangular, elliptical to ovate-elliptical in transverse section, more broadly exposed on convex surface, end walls not thickened.  Sexual condition monoicous or dioicous.  Capsule 2 mm or more, with scattered pseudomata.  Spores less than 30 \um, both surfaces smooth to finely papillose; proximal laesura more than 0.5 spore radius.

Species 4 (4 in the flora): North America, Eurasia, Pactific Islands (New Zealand).

 

 

1.   Branch leaves markedly truncate; chlorophyll cells ovate-triangular in transverse section, with the widest part at or near the convex surface
............................................................................ 19.   Sphagnum tundrae

1.   Branch leaves not truncate; chlorophyll cells elliptical to elliptical-ovate with the broadest part typically some distance from the convex surface.

2.   Branch leaves strongly squarrose (terete in tundra forms), large (1.9--3 mm); hyaline cells of branch leaves with ringed elliptic pores on concave surface and unringed pores on convex surface; stem leaves 1/2 to 2/3 as long as branch leaves (1.1--1.9 mm)........ 17.   Sphagnum squarrosum

2.   Branch leaves imbricate (squarrose in shade forms), moderate in size (1--1.5 mm); hyaline cells of branch leaves with unringed pores on concave and convex surfaces; stem leaves as long or longer than branch leaves (1--1.7 mm).

3.   Branch leaf hyaline cells near leaf base on convex surface mostly aporose and on concave surface with large, faint pores; 1--2 hanging branches.................................................... 16.   Sphagnum mirum

3.   Branch leaf hyaline cells near leaf base on convex surface with large, round pores and on concave surface mostly aporose; 2--3 hanging branches....................................................... 18.   Sphagnum teres

 

16.  Sphagnum mirum   Flatberg & Thingsgaard, Bryologist 106. 501.  2003    E

Plants fairly slender to moderate-sized, green; forming low dense hummocks.  Stems yellowish green; 3 layers of superficial cortical cells.  Stem leaves generally longer than branch leaves, 1.1--1.7 mm, lingulate to lingulate-spathulate, hyaline cells mostly non-septate.  Branches terete.  Branch fascicles of 2 spreading and 1--2 hanging branches.  Branch stems with 1---2 layers of cortical cells.  Branch leaves 1--1.4 mm, broadly ovate, with a narrow involute tip; hyaline cells only slightly bulging on either surface, in proximal half of leaf aporose on convex surface and with large faint pores on concave surface; internal commissural walls distinctly papillose; chlorophyllous cells elliptical to elliptical-triangular in transverse section, enclosed on both surfaces with the widest part in the leaf middle.  Sexual condition dioicous.  Spores

ca 31 \um, ornamented by small somewhat amalgamated granulae.

Sporophytes abundant, capsules mature August.  Ecology poorly known but probably quite minerotrophic; Alaska**w**.

Sphagnum mirum has only been recently discovered and so far is known only from its type locality in Alaska, where it was growing in a fen mixed with S. teres.

 

17.  Sphagnum squarrosum   Crome, Samml. Deutsch. Laubm., 24. 1803; also Bot. Zeit. Regnesb. 2: 324.  1803

Sphagnum squarrosum var. imbricatum Schimper

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 x 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 \um; proximal surface finely papillose, distal surface smooth with raised bifurcated Y-mark sculpture; proximal laesura more than 0.5 spore radius.

Sporophytes abundant, capsules mature early to mid-summer.  Forming loose carpets in rich habitats such as wet coniferous forests, Thuja swamps, karrs, medium fens, and stream margins; Greenland**c**; Alta.**c**, B.C.**c**, Man.**c**, N.B., Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Nunavut**c**, Ont.**c**, P.E.I., Que.**c**, Sask.**n**, Yukon,**c**; Alaska**c,AI,PH**, Ariz., Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Y., N.C., Oreg., Pa., S.D., Tenn., Vt., Wash., W.Va., Wis., Wyo.; Eurasia; Pacific Islands (New Zealand).

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 of S. strictum.

 

18.  Sphagnum teres   (Schimper) Ångstrom, Skand. Fl. ed. 8, 417.  1861

Sphagnum squarrosum var. teres Schimper, Versuch Torfm., 64. 1858; S. teres var. squarrosulum (Schimper) Warnstorf

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 x 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 \um; proximal and distal surfaces smooth, papillae indistinct; proximal laesura 0.5--0.6 spore radius.

Sporophytes uncommon, capsules mature late spring to early summer.  Strongly minerotrophic, in open to medium rich fens, less frequent in coniferous mires, characteristic species of rich, weakly acidic to slightly basic mires; Greenland**s**; Alta.**c**, B.C.**c**, Man.**c**, Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Nunavut**c**, Ont.**c**, Que.**c**, Sask.**n**, Yukon,**n**; Alaska**c,AI,PH**, Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Y., N.Dak., Ohio, Oreg., Pa., Vt., Wash., Wis., Wyo.; Eurasia.

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

 

19.  Sphagnum tundrae   Flatberg, Lindbergia 19: 3, figs. 1--3.  1994    F

Plants small to moderately robust, green to yellow green, with a brownish tinge in hummocks; forms mats and cushions.  Stems yellowish green with some brown bands; 2--3 layers of superficial cells.  Stem leaves shorter than branch leaves, 0.8--1.6 mm, lingulate, hyaline cells non-septate above and commonly 1-septate below.  Branches short and blunt, branch leaves imbricate.  Branch fascicles typically with 2 spreading and 2 hanging branches.  Branch stems with single layer of cortical cells.  Branch leaves 0.9--2 mm, ovate, with conspicuously truncate apex, hyaline cells bulging on both surfaces, with 1--4 large circular to elliptic pores per cell on convex surface and 4--7 elliptic pores per cell on concave surface, internal commissural walls faintly papillose, cholrophyll cells elliptical to elliptical-ovate withn the broadest part typically some distance from convex surface.  Sexual condition unknown.

Forms mats and cushions in weakly minerotrophic arctic mires; Yukon**n**; Alaska**n**; Europe.

Sphagnum tundrae can be separated from other species in sect. Squarrosa most readily by its truncate branch leaves.

 

1e.  Sphagnum   sect.  Isocladus   (Lindberg) Braithwaite, Sphag. 30.  1880

Isocladus Lindberg, Oefv. K. Vet. Ak. Foerh. 19: 133.  1862

Plants coarse and robust; usually found floating, submerged or stranded; capitulum not apparent, leaves crowded into a tuft; deep green throughout or dark reddish brown to blackish brown with yellowish branch tips when wet and shiny pale green to straw colored or brown when dry.  Stems green to brownish, superficial cortex of 2--3 layers of inflated, thin-walled, efibrillose, non-ornamented, aporose cells.  Stem leaves much smaller than branch leaves, broadly triangular with a rounded apex, border entire, hyaline cells rhomboid, efibrillose and non-ornamented; convex surface aporose; concave surface with 0--5 round or oblong pores with either 1 central pore or pores in a single row.  Branches more or less monomorphic.  Branch fascicles with 2--3 branches.  Branch stems green, surrounded by 1--3 layers of enlarged, thin-walled, efibrillose, non-ornamented, mostly aporose cells.  Branch leaves lanceolate, linear-lanceolate to ovate-ligulate, apex tubular and involute or flat and rounded, with numerous small pores (8--60 per cell) on the convex surface in 1--3 irregular rows, nearly aporose on the concave surface; chlorophyllous cells rectangular in transverse section and equally exposed on both surfaces.  Sexual condition dioicous.  Capsule with few pseudostomata or pseudostomata absent.  Spores 25--35 \um; smooth to finely papillose on proximal and distal surfaces, conspicuous bifurcated Y-mark sculpture on distal surface; proximal laesura less than 0.5 spore radius.

Species 2 (2 in the flora): North America.  

 

1.   Branch leaves with 20--40 pores, each less than 0.25 width of cell, mostly in 2 rows, branch leaves ovate-ligulate with a broad, rounded, truncate apex........................................................................ 20.   Sphagnum cribrosum

1.   Branch leaves with 8--12 pores, each more than 0.25 width of cell, mostly in 1 row, branch leaves lanceolate to linear-lanceolate with a narrow tubular apex.......................................................... 21.   Sphagnum macrophyllum

 

20.  Sphagnum cribrosum   H. Lindberg, Eur. Nord Amer. Hvitm. 74.  1882    E

Sphagnum floridanum (Austin) Cardot; S. macrophyllum var. floridanum Austin

Plants green, light brown to brown.  Branch leaves ovate-ligulate, apex broad, rounded, and truncate, hyaline cells with 20--40 small (less than 0.25 cell diameter) in mostly 2 rows.

Floating or stranded at margins of shallow acidic lakes and ponds; Fla., Ga., Md., N.C., S.C.

Besides the different branch leaf porosity, this species is usually distinguishable from the closely related Sphagnum macrophyllum by its paler brown color and distinctly broader and more truncate branch leaves.  "Wave forms" of both S. cribrosum and S. macrophyllum, seemingly developed in response to growing in shallow water where wave action is common, can have very odd phenotypes that may look more like Fontinalis than Sphagnum.

 

21.  Sphagnum macrophyllum   Bridel, Bryol. Univ. 1: 10.  1826    E

Isocladus macrophyllus (Bridel) Lindberg; Sphagnum macrophyllum var. burinense W. S. G. Maas

Plants brown, dark brown to nearly black.  Branch leaves lanceolate to linear-lanceolate, apex narrow and tubular, hyaline cells with 8--12 moderate-sized (more than 0.25 cell diameter) in mostly one row.

Floating or stranded at margins of shallow lakes and ponds, rarely in seeps where probably constantly wet; Nfld. and Labr. (Nfld.), N.S.; Ala., Ark., Del., Fla., Ga., La., Md., Miss., N.J., N.Y., N.C., S.C., Tenn., Tex., Va.  

 

1f.  Sphagnum   sect.  Cuspidata   Lindberg, Oefv. K. Vet. Ak. Foerh. 19: 134.  1862

Sphagnum sect. Acisphagnum J. K. A. Müller, illegitimate name, S. sect. Mollusca A. Casares-Gil

Plants varying from lax free floating forms to compact terrestrial forms, usually with distinct capitulum; green, whitish, pale, yellow-green to light brownish, rarely dark-colored.  Stems green, brown dark brown to occasionally pinkish in parts, superficial cortex of 0--4 layers of efibrillose, non-ornamented, enlarged, thin-walled cells, cells in outer layer aporose.  Stem leaves usually smaller than branch leaves, triangular to lingulate, apex apiculate, acute, broad, or erose and split, border narrow or broad at base; hyaline cells non-ornamented, usually efibrillose (in proximal portion) to often fibrillose in distal portion of leaf, aporose or with few pores and septate to nonseptate.  Branches dimorphic, pendent branches more slender and delicate than spreading branches.  Branch fascicles with 2--3 spreading to 1--3 pendent branches.  Branch stems green to pinkish, surrounded by 1 layer of efibrillose, non-ornamented, enlarged, thin-walled cells, with solitary uniporose retort cells (or in groups) with short necks, other aporose cells rectangular.  Branch leaves usually longer than stem leaves, ovate to lanceolate; margins entire or in a few cases serrulate; apex involute and smooth; hyaline cells non-ornamented, fibrillose (in one case efibrillose), convex surface porose or with a few to numerous pores or pseudopores, concave surface aporose or with pores or pore-like wall thinnings; chlorophyllous cells triangular to trapezoidal in transverse section, more broadly exposed on convex surface, end walls not thickened.  Sexual condition mostly dioicous or occasionally monoicous.  Capsule less than 2 mm, with few pseudostomata.  Spores usually more than 30 \um, rarely with raised surface sculpture on distal surface; proximal laesura typically less than or equal to 0.5 spore radius.

Species ca. 55 (29 in the flora):   worldwide in distribution excepting Antarctica.

 

1.   Stem leaves lacerate across all or part of apex.

2.   Stem leaves lingulate-spatulate, lacerate across broad apex and partially down the sides............................................ 35.   Sphagnum lindbergii

2.   Stem leaves lingulate to triangular-lingulate, lacerate or notched in middle of apex only.

3.   Stem leaves lingulate; branch leaves not sharply recurved when dry and typically strongly 5-ranked; plants strongly brown-pigmented, small and compact.................................... 34.   Sphagnum lenense

3.   Stem leaves triangular-lingulate; branch leaves sharply recurved when dry and rarely five-ranked; plants typically green, large and not especially compact.................................. 44.   Sphagnum riparium

1.   Stem leaves erose to entire at apex.

4.   Branch leaf hyaline cells efibrillose................ 46.   Sphagnum splendens

4.   Branch leaf hyaline cells fibrillose.

5.   Branch leaf hyaline cells with 5 or more free pores per cell in lower portion of convex surface.

6.   Branch leaf hyaline cells lacking pores or wall thinnings on concave surface.................................... 36.   Sphagnum majus

6.   Branch leaf hyaline cells with pores or wall thinnings on concave surface.

7.   Branch leaf hyaline cells with round wall thinnings in the cell angles and apices on the concave surface.

8.   Stem leaves fibrillose at apex; stem leaves spreading at right angles; common species of northern peatlands
............................... 25.   Sphagnum balticum (in part)

8.   Stem leaves normally efibrillose and appressed.

9.   Branch leaves ovate, stem cortex well-differentiated but not enlarged 33.   Sphagnum kenaiense (in part)

9.   Branch leaves ovate-lanceolate, stem cortex undifferentiated.... 45.   Sphagnum rubroflexuosum

7.   Branch leaf hyaline cells with pores or wall thinnings free from the cell margins on the concave surface.

10. Stem leaves lingulate to triangular-lingulate and with a more or less erose apex; branch leaf pores faint (visible only with heavy staining)............................ 40.   Sphagnum obtusum

10. Stem leaves triangular and with an obtuse, entire apex; branch leaf pores obvious.

11. Branch leaf hyaline cells with numerous free pores on convex surface in distal region, branch leaf hyaline cells relatively short and wide in proximal portion........................ 23.   Sphagnum annulatum

11. Branch leaf hyaline cells with numerous pseudopores along commissures on convex surface in distal region; branch leaf hyaline cells relatively long and narrow in proximal portion 32.   Sphagnum jensenii

5.   Branch leaf hyaline cells with less than 5 free pores per cell in proximal portion of convex surface.

12. Branch leaves with numerous pores along the commissures on both surfaces, round wall thinnings in cell angles and apices not present on concave surface......... 38.   Sphagnum mendocinum

12. Branch leaves with few or no pores along the commissures on either surface; round wall thinnings present in cell angles and apices on concave surface.

13. Stem leaves lingulate to ovate-lingulate and with incurved distal margins.

14. Branch leaves ovate to ovate-lanceolate, moderately concave, slightly undulate and recurved, often 5-ranked
............................... 25.   Sphagnum balticum (in part)

14. Branch leaves ovate, strongly concave, neither undulate nor recurved, not 5-ranked... 47.   Sphagnum tenellum

13. Stem leaves various but not as above.

15. Branch leaves with serrulate margins.

16. Branch leaves with broad, rounded apex
................................... 29.   Sphagnum fitzgeraldii

16. Branch leaves with pointed involute apex.

17. Branch leaves ovate to broadly ovate; spreading branches short, little tapered to distal end
..................... 39.   Sphagnum mississippiensis

17. Branch leaves ovate-lanceolate to lanceolate; spreading branches long, tapered to distal end
............................... 49.   Sphagnum trinitense

15. Branch leaves entire along margins.

18. Stem leaves lingulate to triangular-lingulate with more or less erose apex.

19. Branch leaves sharply recurved when dry; stem leaves fibrillose at apex............ 43.   Sphagnum recurvum

19. Branch leaves slightly recurved when dry; stem leaves efibrillose or fibrillose at apex.

20. Stem leaves spreading, efibrillose distally
............. 25.   Sphagnum balticum (in part)

20. Stem leaves appressed, fibrillose distally

21. Branch leaves ovate, stem cortex well-differentiated but not  enlarged
..... 35.   Sphagnum kenaiense (in part)

21. Branch leaves ovate-lanceolate, stem cortex undifferentiated.. 30.   Sphagnum flexuosum

18  Stem leaves triangular to triangular-lingulate, acute to obtuse but rarely erose.

[key continued at left margin]

22. Stem leaves less than 0.8 mm, triangular...... 22.   Sphagnum augustifolium

22. Stem leaves 0.8 mm or more (if shorter, then apiculate), triangular to triangular-lingulate.

23. Branch leaves typically broadly ovate with an abruptly involute apex
................................................................... 42.   Sphagnum pulchrum

23. Branch leaves ovate-lanceolate to lanceolate with a tapered involute apex.

24. Sem leaves apiculate; young pendent branches in pairs between rays of the capitulum; carpet forming species with branch leaves not greatly elongated at distal branch end.

25. Branch leaves strongly recurved when dry.

26. Branch leaf chlorophyll cells wall-enclosed on concave surface; stem cortex with strongly enlarged thin-walled cells................................................ 41.   Sphagnum pacificum

26. Branch leaf chlorophyll cells slightly enclosed on or just reaching concave surface; stem cortex with moderately enlarged and thick-walled cells......... 28.   Sphagnum fallax

25. Branch leaves weakly recurved when dry.

27. Branch leaves relatively narrow, with length to width ratio ca. 3.2; stem leaves relatively broad, with length to width ratio 1:1.14; branch leaves typically strongly five-ranked
................................................... 31.   Sphagnum isoviitae

27. Branch leaves relatively broad, with length to width ratio ca. 2.8; stem leave relatively narrow, with length to width ratio ca. 1:1.22; branch leaves unranked or only weakly five-ranked................................... 26.   Sphagnum brevifolium

24. Stem leaves obtuse to apiculate; young pendent branches not in pairs between the branches of the capitulum; aquatic species with branch leaves substantially elongated at distal branch end.

28. Branch leaf chlorophyll cells very well-enclosed on concave surface.

29. Branch leaf chlorophyll cells in transverse section well-enclosed and reaching only ca. 1/2 the distance to the concave surface; branch leaves often falcate-secund
............................................... 24.   Sphagnum atlanticum

29. Branch leaf chlorophyll cells slightly enclosed and reaching about 3/4 the distance to the concave surface; branch leaves typically straight..................... 48.   Sphagnum torreyanum

28. Branch leaf chlorophyll cells slightly enclosed or reaching concave surface.

30. Stem leaves obtuse, spreading and with septate hyaline cells in the proximal mid-region............... 37.   Sphagnum mcqueenii

30. Stem leaves acute to apiculate, appressed and with non-septate hyaline cells in proximal mid-region.

31. Branch leaves relatively narrow, length to width equal or greater than 3.6:1, hyaline cells in distal region convex surface 8--15:1; capitulum often twisted................. 27.   Sphagnum cuspidatum

31. Branch leaves relatively broad, length to width less than 3.6:1, hyaline cells in distal region convex surface 4--8:1; capitulum with straight branches....................... 50.   Sphagnum viride

 

22.  Sphagnum angustifolium   (Russow) C. E. O. Jensen in K. R. Tolf, Bih. Sv. Vet.-Akad. Handl. 16, Afd. 3(9): 46.  1891

Sphagnum recurvum subsp. angustifolium Russow, Sitz.-ber. Nat.-Ges. Dorpat 9: 112.  1890; S. amblyphyllum var. parvifolium (Sendtner) Warnstorf; S. flexuosum var. tenue (H. Klinggraff) Pilous; S. parvifolium (Warnstorf) Warnstorf; S. recurvum var. parvifolium Warnstorf; S. recurvum var. tenue H. Klinggraff

Plants small and often slender and soft, lax to compact, moderately stiff-stemmed; green to pale yellow to golden-brown to brown; capitulum strongly convex in drier grown forms to strongly 5-radiate and flat in wetter growing forms.  Stems pale green to pale brown, often with pinkish red patches, cortex undifferentiated.  Stem leaves equilateral to isosceles-triangular, small, less than 0.8 mm, mostly appressed to stem, apex acute to obtuse, hyaline cells efibrillose and nonseptate.  Branches straight to slightly curved, usually 5-ranked; leaves not much longer at distal end than proximal end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems with cortex enlarged with conspicuous retort cells, often pinkish red at proximal end.  Branch leaves narrowly ovate-lanceolate, 0.8--1 mm, straight, moderately undulate and recurved in larger and/or wetter grown forms, not undulate and slightly recurved in compact forms from drier sites; margins entire; hyaline cells on convex surface with 1(2--3) pore per cell at apical end of cell, on concave surface with round wall thinnings in cell ends and angles; chlorophyllous cells triangular in transverse section and just enclosed on concave surface.  Sexual condition dioicous.  Spores 21--25 \um; coarsely papillose on proximal and distal surfaces; proximal laesura more than 0.5 spore radius.

Wide range of habitats, from ombrotrophic to rich fens, open mires, sedge fens and muskeg, as carpets, floating mats, low hummocks and hummock sides; Greenland**s**; Alta.**c**, B.C.**c**, Man.**c**, N.B., Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Ont.**c**, Que.**c**, Sask.**n**, Yukon,**c**; Alaska**c,AI,PH**, Calif., Colo., Idaho, Ill., Ind., Maine, Md., Mass., Mich., Minn., Mo., Mont., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Oreg., Pa., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Eurasia.

The sporophytes of Sphagnum angustifolium are somewhat common.  This species is distinguished from similar species in section Cuspidata by the small, triangular, obtuse and appressed stem leaves.  Sphagnum angustifolium also often has a pink stem, as opposed to the reddish branch bases seen in some other species of the section.  Sphagnum balticum has stem leaves that are more lingulate-triangular as well as spreading from the stem.  Sphagnum angustifolium belongs to a subgroup within sect. Cuspidata usually referred to as S. recurvum s.l., a group of mostly carpet-forming species that differ from species of the section in having pairs of pendent branch buds visible between the capitulum rays.  The group also includes S. brevifloium, S. fallax, S. flexuosum, S. pacificum, S. recurvum, S. rubroflexuosum and S. splendens.

 

23.  Sphagnum annulatum   Warnstorf, Bot. Centralbl. 76: 422.  1898    F

Sphagnum jensenii var. annulatum (Warnstorf) Warnstorf

Plants moderate-sized and weak-stemmed; in lawns and floating mats; brownish green, brown, reddish brown to chestnut-brown, often with bluish tint when dry, capitulum 5-radiate and flat-topped.  Stems pale green to brown; cortex poorly differentiated to undifferentiated.  Stem leaves lingulate-triangular to triangular-lingulate, equal to or less than 1.2 mm, more or less spreading; apex obtuse; hyaline cells mostly fibrillose and nonseptate.  Branches straight to distinctly curved, leaves becoming substantially longer at distal end of the branch.  Branch fascicles with 2 spreading and 1--2 pendent branches.  Branch stems green, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate, 1.5--2 mm, straight to slightly subsecund, only slightly undulate and recurved if at all; margin entire; hyaline cells on convex surface with numerous small free pores, on concave surface with numerous round free pores, cells relatively short in basal region (similar to mid-region); chlorophyllous cells +/- triangular in transverse section, just reaching concave surface or slightly enclosed.  Sexual condition dioicous.  Spores 25--32 \um, finely papillose on both surfaces.

Wet carpets, lawns, and mud bottoms in poor to medium fens, in mire-wide and mire-edge habitats; Alta.**n**, B.C.**n**, Man.**n**, Nfld. and Labr. (Nfld.), N.W.T.**c**, Ont.**n**, Que.**n**, Yukon**c**; Alaska**s**, Idaho, Mich., Minn., Mont., N.Y., Wash., Wyo.; Eurasia.

Sporophytes are rare in Sphagnum annulatum.  Of the more wet-growing species, both S. cuspidatum and S. viride are typically much more green or yellow and have stem leaves with acute apices.  Sphagnum jensenii is usually larger and has straight capitulum branches as opposed to the more curved branches of S. annulatum.  Sphagnum majus normally has a denser and more rounded capitulum.  Field experience in both Alaska and Scandanavia, where both species occur, does not support the view of H. A. Crum (1997) that S. annulatum and S. jensenii are simply ends of a continuum.  Both species are usually readily separable in the field and look quite different in mixed populations.  In North America at least S. annulatum is also considerably more widespread.

 

24.  Sphagnum atlanticum   R. E. Andrus, Bryologist 110: ---.  2007.  E   {{TO BE PUBLISHED IN 2007   }}

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.  Stems green to brown; superficial cortex of 1--2 layers of moderately thick-walled and poorly differentiated cells.  Stem 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.  Branches unranked, long and tapering, leaves greatly elongate at distal end.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stem green, cortex enlarged with conspicuous retort cells.  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.  Sexual condition dioicous.  Sporophytes not seen.

Forming loose carpets in pools in weakly minerotrophic fens; N.B., Nfld and Labr. (Nfld.), N.S.; Conn., Del., Mass., Maine, Md., N.H., N.J., N.Y., N.C., Pa., Vt., Va.

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.

 

25.  Sphagnum balticum   (Russow) C. E. O. Jensen, Fests. Bot. For. Kjob., 100.  1890

Sphagnum recurvum subsp. balticum Russow, Sitz.-ber. Nat.-Ges. Dorpat 9: 99.  1890

Plants small to moderate-sized, soft and +/- weak-stemmed; brownish green, yellow-green, yellowish to golden-brown, capitulum typically flat and 5-radiate.  Stems pale green to brown, branch bases sometimes reddish; superficial cortex of 2--3 layers of moderately thin-walled and differentiated cells.  Stem leaves 0.8--1.1 mm, triangular-lingulate to lingulate, concave, spreading, apex broadly obtuse, hyaline cells fibrillose in apical region.  Branches slender and tapering, often 5-ranked and decurved, leaves somewhat elongated at distal end.  Branch fascicles with 2 spreading and mostly 1 pendent branch.  Branch stem green, cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate, 1--1.7 mm, straight, slightly undulate and spreading ; margin entire, hyaline cells on convex surface with 1--5 pores in cell ends and free near apex, on concave surface with round wall thinnings in cell ends and angles; chlorophyllous cells triangular in transverse section and well-enclosed on concave surface.  Sexual condition dioicous.  Spores 25--33 \um; smooth to finely papillose on both surfaces; proximal laesura approximately 0.5 spore radius.

Abundant in hollows and floating mats in raised bogs and poor fens; Greenland**c**; Alta.**n**, B.C.**n**, Man.**n**, N.W.T.**c**, Nunavut**c**, Ont.**n**, Que.**n**, Yukon,**c**; Alaska**c,PH**, Colo.; Eurasia.

Compared to Sphagnum angustifolium and S. annulatum, S. balticum has stem leaves exerted at right angles to the stem.  Sphagnum balticum also has fewer and weaker hanging branches than S. angustifolium, which make the stem itself often visible and the stem leaves easier to see.  Sphagnum balticum also lacks the paired pendent branch buds between the capitulum rays as seen in S. angustifolium.

 

26.  Sphagnum brevifolium   (Lindberg) J. Röll, Bot. Centralbl. 39: 340.  1889

Sphagnum cuspidatum var. brevifolium Lindberg, Sphag., 84.  1880

Plants small and slender to moderate-sized, soft, not very compact; pale yellow, yellowish brown to brown; capitulum flat to somewhat convex, not 5-radiate to somewhat 5-radiate.  Stems pale yellow to pale green, sometimes with reddish portions, superficial cortex of 2--3 layers of clearly differentiated cells.  Stem leaves triangular to lingulate-triangular, apex apiculate, acute and sometimes slightly obtuse, spreading or sometimes appressed; hyaline cells nonseptate and often fibrillose at leaf apex.  Branches straight to distinctly curved, leaves unranked to 5-ranked, leaves not greatly elongate at branch distal end.  Branch fascicles with 2 spreading and 1--2 pendent branches.  Branch stems with cortex enlarged with conspicuous retort cells, sometimes reddish at proximal end.  Branch leaves ovate to ovate-lanceolate, greater than 1.2 mm, often subsecund, slightly undulate and slightly recurved when dry; margin entire; hyaline cells on convex surface with 1 pore per cell in apical end, on concave surface with round wall thinnings in the cell ends and angles; chlorophyllous cells equilateral to isosceles-triangular, well-enclosed on the concave surface.  Sexual condition dioicous.  Spores not seen.

Ecology not presently understood due to past confusion with other species; Nfld. and Labr. (Nfld.), Que.**n**; Alaska**s**, Maine, Md., Mich., Minn., N.H., N.Y., Vt.; Europe.

Details of the distribution of Sphagnum brevifolium are unclear because of confusion with S. fallax and S. isoviitae.  This seems to be a species of poor to medium fens where it occurs in depressions and floating mats; it does not appear to form extensive fast-growing mats as do S. fallax, S. isoviitae, and S. pacificum.  Sphagnum brevifolium is one of five Sphagnum recurvum “s.l.” species with apiculate stem leaves.  On the Pacific coast it seemingly co-occurs only with S. pacificum, from which it differs in having branch leaves less sharply recurved and more strongly 5-ranked.  In eastern North America it is quite uncommon but can occur with both S. fallax and S. isoviitae of S. recurvum s.l.  Sphagnum fallax has more sharply recurved branch leaves.  Sphagnum splendens has a distinct shiny look.  The much more common S. isoviitae has a distinctly flatter capitulum, narrower branch leaves and wider stem leaves.  In fact, the relatively broad branch leaves of S. brevifolium sometimes can give it the appearance of a slender S. pulchrum, but the latter has much more strongly 5-ranked branch leaves and lacks paired pendent branch buds.  See also the discussion of S. angustifolium.

 

27. Sphagnum cuspidatum   Hoffman, Deutsch. Fl., 2: 22.  1796

Sphagnum cuspidatum var. plumosum Nees & Hornschuch; S. faxonii Warnstorf; S. virginianum Warnstorf

Plants slender and weak-stemmed, moderate-sized, flaccid and plumose in aquatic forms to more compact in emergent forms, spreading branches often conspicuously falcate, giving capitulum a twisted appearance; green to yellow, often tinged with red, red-brown or brown in capitula.  Stems green; superficial cortex of 2--3 layers 2 layers of enlarged thin-walled cells.  Stem leaves triangular-ovate, more than 1.2 mm, usually appressed; apex acute to apiculate, hyaline cells rarely septate or porose, apical region often fibrillose.  Branches mostly unranked to weakly 5-ranked, often conspicuously falcate, leaves greatly elongated at distal end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems green, but often pinkish at the proximal ends, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate to lanceolate, 1.6--5 mm, falcate toward branch tips, when dry often undulate and recurved, rarely weakly serrulate along the margins in submerged forms, leaves from middle of spreading branches with length to width ratio less than or equal to 1:0.28; hyaline cells length to width ratio in apical convex surface region 8:1 or more, convex surface with 0--1 small round pores at apex, concave surface with faint round wall thinnings in cell apices and angles; chlorophyllous cells triangular to trapezoidal in transverse section, broadly exposed on the convex surface and exposed slightly on the concave surface.  Sexual condition dioicous.  Spores 29--38 \um; covered with large papillae on both surfaces, appearing pusticulate; proximal laesura less than 0.5 spore radius.

Sporophytes are occasional, capsules mature in early to mid-summer.  Widespread forming wet carpets in ombrotrophic to weakly minerotrophic mires; N.B., Nfld. and Labr. (Nfld.), N.S., Ont.**s**, Que.**c**; Ala., Conn., Del., Fla., Ga., Ill., Ind., Kans., Maine, Md., Mass., Mich., Minn., Miss., N.H., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Vt., Va., W.Va., Wis.; Europe.

Distinguishing Sphagnum cuspidatum from S. viride is sometimes difficult, as both occur over a similar geographic range and both grow in wet carpets.  Sphagnum cuspidatum has narrower branch leaves and usually a distinct red tinge at the branch bases within the capitulum.

 

28.  Sphagnum fallax   (H. Klinggraff) H. Klinggraff, Topogr. Fl. Westpr. 128.  1880

Sphagnum cuspidatum var. fallax H. Klinggraff, Schr. Phys.-Ok. Ges. Konigsb. 7.  1872; S. apiculatum H. Lindberg; S. flexusoum var. fallax (H. Klinggraff) A. J. E. Smith; S. mucronatum (Russow) Zickendrath; S. recurvum var. brevifolium (Braithwaite) Warnstorf; S. recurvum var. fallax (H. Klinggraff) H. K. G. Paul; S. recurvum subsp. mucronatum Russow

Plants moderate-sized, fairly stiff-stemmed; green, brownish green, pale yellow, golden-yellow, yellow and brown; capitulum hemispherical and not 5-radiate to somewhat 5-radiate in shade-grown or wet-grown forms.  Stems pale green to pale brown, superficial cortex of 2 layers of moderately differentiated cells.  Stem leaves triangular to lingulate-triangular, 0.8--1.2 mm, mostly appressed to the stem, apex acute to apiculate, hyaline cells mostly efibrillose and nonseptate.  Branches straight, mostly unranked, but can be 5-ranked in wet-growing forms, leaves little elongated at distal branch ends.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems green but proximal end sometimes red, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate, greater than 1.2 mm, straight, undulate and sharply recurved when dry, margins entire; hyaline cells on convex surface with usually 1 round pore per cell at apical end, on concave side with round wall thinnings in the cell ends and angles; chlorophyllous cells triangular and just reaching or slightly enclosed within the concave surface.  Sexual condition dioicous.  Spores 25--31 \um; proximal surface finely papillose, distal surface pusticulate with bifurcated Y-mark sculpture; proximal laesura less than 0.5 spore radius.

Sporophytes are uncommon, capsules mature early to mid-summer.  Widespread in poor fen habitats, often as a pioneer species in extensive mats, occasionally in ombrotrophic mires at hummock bases; N.B., Nfld. and Labr. (Nfld.), N.S., Ont.**s**, P.E.I., Que.**s**; Conn., Del., Ill., Ind., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., Tenn., Vt., Va., W.Va.; Europe.

Sphagnum fallax can be distinguished from the closely related S. isoviitae by its sharply recurved branch leaves, as opposed to the leaves of the latter only slightly reflexed at their tips.  See also discussion of S. brevifolium and S. splendens.

 

29.  Sphagnum fitzgeraldii   Lesquereux & James, Man. 23.  1884    E

Sphagnum mohrianum Warnstorf

Plants small and weak-stemmed, flaccid and +/- plumose when submerged to (more frequently) sprawling in thin mats; capitulum +/- compact and with a strong terminal bud; pale green to greenish white.  Stem pale green; superficial cortex of 1--2 layers of thin-walled and well differentiated cells.  Stem leaves large, ovate to oblong-ovate, ca. 2 mm, more or less spreading; apex rounded and serrulate; hyaline cells fibrillose and often 1--septate, convex surface generally aporose, concave surface with 1--several round pores per cell in ends and angles.  Branches unranked to slightly 5-ranked, often short and blunt at distal end.  Branch fascicles with 1--2 spreading and 0--1 pendent branches.  Branch stems green, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate to oblong-quadrate, 1.2--2.5 mm, not undulate or recurved when dry, strongly toothed across apex and serrulate on margins; hyaline cells with to 4 small round ringed pores at cell ends on convex surface, small round wall thinnings in the cell ends and angles on the concave surface; chlorophyllous cells trapezoidal in transverse section, more broadly exposed on the convex surface.  Sexual condition monoicous.  Spores 38--48 \um; both surfaces covered with fine to moderately coarse papillae; proximal laesura less than 0.4 spore radius.

Commonly in prostrate mats on damp sand, often in recently burned or cleared areas, also occasionally floating in ditches; Ala., Fla., Ga., La., Miss., N.C., S.C., Va.

Sporophytes of Sphagnum fitzgeraldii are common, being immersed or exserted.  This species is found largely on the Atlantic coastal plain.  The wide truncate branch leaves easily distinguish S. fitzgeraldii in most situations.  Floating plants are not as quickly identified but can be told from other similar species of sect. Cuspidata by the branch leaves wider than those of similar species.

 

30.  Sphagnum flexuosum   Dozy & Molkenboer, Prodr. Fl. Batav. 2(1): 76.  1851

Sphagnum amblyphyllum (Russow) Zickendrath; S. fallax var. flexuosum (Dozy & Molkenboer) Nyholm; S. flexuosum var. ramosissimum R. E. Andrus; S. flexuosum var recurvum Dozy & Molkenboer; S. recurvum subsp. amblyphyllum Russow; S. recurvum var. amblyphyllum (Russow) Warnstorf

Plants small to moderate-sized, slender and soft, lax, moderately weak to moderately stiff-stemmed; green, pale yellowish green, yellowish brown, grayish brown or reddish brown; capitulum typically compact and twisted in the middle like a ball of yarn, spreading branches curved giving a pinwheel appearance.  Stems pale green to pale brown, rarely with pinkish red patches, superficial cortex of undifferentiated to slightly differentiated.  Stem leaves triangular-lingulate to lingulate, 0.7--1.3 mm, appressed to stem, apex obtuse to broadly obtuse and erose to somewhat lacerate, hyaline cells efibrillose and nonseptate.  Branches curved, unranked to less commonly (in wet-grown forms) 5-ranked, leaves not much elongate at distal end.  Branch fascicles with 2(--3) spreading and 2 pendent branches.  Branch stems green but sometimes reddish at proximal end, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate to broadly ovate-lanceolate, 1.5--2.5 mm, strongly undulate and moderately recurved when dry, straight; margin entire; greater than hyaline cells on convex surface with 1--2 pores per cell at cell apex, on concave surface with round wall thinnings in the cell ends and angles; chlorophyllous cells triangular in transverse section and typically just slightly exposed on the concave surface.  Sexual condition dioicous.  Spores 23--25 \um; moderately to coarsely papillose on both surfaces; proximal laesura approximately 0.5 spore radius..

Sporophytes uncommon, capsules mature early to late summer.  Forming carpets in poor to medium fens, mostly sedge-fens and mire edge habitat; N.B., Nfld. and Labr. (Nfld.), N.S., Ont.**s**, P.E.I., Que.**s**; Conn., Ill., Ind., Maine., Md., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., Tenn., Vt., W.Va., Wis.; Europe.

Of species with range and ecology similar to that of  Sphagnum flexuosum in sect. Cuspidata, Sphagnum angustifolium and S. recurvum, have rounded stem leaves.  In S. angustifolium the stem leaves are more triangular and rarely erose while the branch leaves are narrower and more strongly 5-ranked.  Sphagnum recurvum also has narrower and more 5-ranked branch leaves than S. flexuosum as well as a much more strongly differentiated stem cortex.  In S. flexuosum the branch leaves are only slightly recurved whereas in S. recurvum they are sharply recurved.

 

31.  Sphagnum isoviitae   Flatberg, J. Bryol. 17: 2, figs. 1, 2.  1992

Plants moderate-sized and moderately weak-stemmed to moderately stiff; green, brownish green to brown; capitulum flat-topped and 5-radiate, terminal bud often visible.  Stems pale green, rarely with red coloration, superficial cortex of 2 layers of moderately to well differentiated cells.  Stem leaves triangular to lingulate-triangular, equal to or more than 0.8 mm, spreading to appressed; apex acute to apiculate, hyaline cells mostly efibrillose and nonseptate.  Branches +/- straight and somewhat tapered, usually 5-ranked, leaves not greatly elongated at branch distal end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems green and often reddish at proximal end, with cortex enlarged with conspicuous retort cells.  Branch leaves narrowly ovate-lanceolate, greater than 1.2 mm, straight, slightly undulate and weakly recurved when dry, margins entire; hyaline cells on convex surface with 1 pore per cell in apical end, on concave surface with round wall thinnings in the cell ends and angles; chlorophyllous cells in transverse section triangular to ovate-triangular and well-enclosed on the concave surface.  Sexual condition dioicous.  Spores 24--33 \um; finely papillose on the superficial surface.

Forming carpets in a wide variety of poor to medium fen habitats of both mire edge and mire wide character, not found in ombrotrophic mires; Alta.**n**, Nfld. and Labr. (Nfld.), N.S., Que.**s**; Conn., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., Vt., Va., W.Va.; Europe.

Sporophytes are uncommon in Sphagnum isoviitae.  See discussion of 28. S. fallax and 26. S. brevifolium for distinction from these similar species.  Sphagnum isoviitae has no range overlap with S. pacificum, the other North American species of Sphagnum recurvum in the broad sense with apiculate stem leaves; the sharply recurved branch leaves of the latter, however, would separate it easily in any case.  Spore features are those given by K. I. Flatberg (1992).

 

32.  Sphagnum jensenii   H. Lindberg, Act. Soc. F. Fl. Fenn. 18(3): 13.  1899    F

Sphagnum annulatum var. porosum (Warnstorf) W. S. G. Maas

Plants moderate-sized to robust, weak-stemmed; pale brown to chestnut brown; capitulum flat-topped and generally 5-radiate, branches straight to somewhat curved, terminal bud often visible.  Stems pale green to brown, superficial cortex of 2 layers of thin-walled and well differentiated cells.  Stem leaves triangular, ovate-triangular to triangular-lingulate, 1--1.3 mm; appressed to spreading; apex obtuse, hyaline cells usually fibrillose near apex.  Branches straight to somewhat curved, leaves moderately elongate at distal end.  Branch fascicles with 2 spreading and 1--2 pendent branches.  Branch stems green, cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate; usually more than 2 mm; straight; weakly undulate and slightly recurved when dry, margins entire; hyaline cells on convex surface with numerous small free pores in proximal 2/3 of leaf and in apical region with numerous pseudopores along commissures, on concave surface with numerous round free pores; cells relatively long and narrow in basal region, much longer than in mid-region; chlorophyllous cells triangular in transverse section and well-enclosed on concave surface.  Sexual condition dioicous.  Spores 29--33 \um; both surfaces very smooth; proximal laesura long, more than 0.6 spore radius.

Predominantly in wet carpets in poor to medium fen habitats, mostly in mire-wide vegetation; Alta.**n**, B.C.**n**, Nfld. and Labr. (Nfld.), N.W.T.**c**, Ont.**n**, Que.**n**, Sask.**n**, Yukon,**c**; Alaska**s**; Eurasia.

Sporophytes of Sphagnum jensenii are uncommon.  For more information, see discussion of S. annulatum.

 

33.  Sphagnum kenaiense   R. E. Andrus, SIDA    E  F   {{TO BE PUBLISHED}}

Plants small and weak-stemmed; grows sprawling in lawns; pale brown to golden brown; capitulum flat-topped and only weakly 5-radiate.  Stems pale yellow; stem cortex moderately well-differentiated but not much enlarged.  Stem leaves appressed to stem; lingulate, ovate, to triangular; equal to or less than 0.9 mm; apex obtuse and often erose to lacerate.  Branches with leaves unranked to 5-ranked, leaves not much elongated at distal branch tip.  Branch fascicles with 2 spreading and 2-3 pendent branches.  Branch leaves ovate, 1.1--1.3 mm long, stiff, weakly undulate and slightly recurved when dry; hyaline cells in mid-region quite short and broad, 3.3--2.5:1, in basal 1/2 of leaf on convex surface often with 1 large pore apically and/or up to 6 free pores, in apical region often with pseudopores along the cell margins; on concave surface with large round wall-thinnings in the cell ends and angles ( these sometimes faint or absent); chlorophyllose cells triangular in transverse section and typically well-enclosed on concave surface.  Sexuality unknown.

Lawns and hollows, typically in sedgey weakly minerotrophic fens. Alaska**c**.

 

34.  Sphagnum lenense   Pohle, Acta Horti Petrop. 33: 14.  1915

Sphagnum lindbergii var. microphyllum Warnstorf, Hedwigia 32: 16.  1893

Plants compact, short-branched and small; strongly reddish to golden brown, glossy when dry; flat-topped capitulum with moderately differentiated terminal bud.  Stems dark brown; superficial cortex of 3--4 layers of enlarged thin-walled cells.  Stem leaves lingulate,small, equal to or less than 0.8 mm, appressed to stem; apex with strong lacerate split in the middle; hyaline cells efibrillose, aporose, and nonseptate.  Branches strongly 5-ranked, short and blunt, not much elongated at distal end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems green, with cortex enlarged with retort cells.  Branch leaves ovate; usually less than 1.5 mm; stiff and slightly reflexed, straight to slightly subsecund; margins entire; hyaline cells moderately long and narrow (6--8:1), convex surface with one small round pore per cell at apex and numerous pseudopores on the margin, concave surface with large round wall thinnings in the cell angles and ends; chlorophyllous cells triangular in transverse section, with apex reaching concave surface.  Sexual condition unknown.  Spores not seen.

Common forming hummocks and carpets in a variety of weakly minerotrophic to ombrotrophic mires including Eriophorum tussock fens, dwarf shrub fens, polygon peatlands, string mires and raised bogs; Greenland**s**; Nfld. and Labr. (Nfld.), N.W.T.**c**, Nunavut**c**, Que.,**n**, Yukon**c**; Alaska**c,AI,PH**, Eurasia.

Sporophytes are rare in Sphagnum lenense.  This species is easily told from the similar S. lindbergii by its compact growth form and reddish brown color.  Sphagnum lenense also is a hummock former in the tundra whereas S. lindbergii forms carpets.

 

35.  Sphagnum lindbergii   Schimper, Öfv. Svenska Vet.-Akad. Förh. 14: 126.  1857

Plants moderate-sized to large, moderately densely branched; green to brown, often bluish tinged and/or shiny when dry; capitulum flattopped with a conspicuous terminal bud.  Stems dark brown; superficial cortex of 2--4 layers of enlarged, thin-walled cells.  Stem leaves lingulate-spatulate, large, 1.3--1.6 mm; appressed to stem; apex very broad and lacerate; hyaline cells efibrillose and aporose, often septate.  Branches strongly 5-ranked and straight.  Branch fascicles with 2 spreading and 2 pendent branches, leaves not much elongated at distal end.  Branch stems green, with cortex enlarged with retort cells.  Branch leaves ovate-lanceolate, 1.5--3 mm; straight to slightly subsecund; imbricate to somewhat reflexed and not undulate; margins entire; hyaline cells long and narrow, length to width ca. 10:1 on convex surface with 1 or more small pores in the cell ends and angles and often with numerous pseudopores along the margins, on concave surface with large round wall thinnings on the cell ends and angles; chlorophyllous cells triangular to trapezoidal in transverse section, apex often exposed on concave surface.  Sexual condition monoicous or dioicous.  Spores 22--34 \um; both surfaces smooth, apparent ridged border on proximal surface; proximal laesura more than 0.5 spore radius.

Widespread forming carpets in ombrotrophic to weakly minerotrophic boreal mires; Greenland**s**; Alta.**n**, B.C.**c**, Man.**c**, Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Nunavut**c**, Ont.**n**, Que.**n**, Yukon,**c**; Alaska**c,AI,PH**, N.H., N.Y., Wash.; Eurasia.

Sporophytes are uncommon. Sphagnum lindbergii is normally easily distinguished from other carpet-forming species of sect. Cuspidata by its large, strongly lacerate stem leaf and dark brown to black stem.  Sexual condition is taken from from L. I. Savicz-Ljubitzkaja and Z. N. Smirnova (1968).

 

36.  Sphagnum majus   (Russow) C. E.O. Jensen, Fests. Bot. For. Kjob., 106.  1890    F

Sphagnum cuspidatum var. majus Russow, Arch. Nat., Dorpat II, 7: 136.  1865

Plants moderate-sized to robust, fairly weak-stemmed, lax in submersed forms, +/- sprawling in emergent froms; golden-brown to dark brown; capitulum weakly 5-radiate, branches straight to strongly laterally curved.  Stems green to pale brown, superficial cortex only weakly differentiated.  Stem leaves triangular-lingulate, 0.8--1.4 mm, spreading to appressed; apex acute to narrowly obtuse, hyaline cells nonseptate and fibrillose near apex.  Branches unranked or weakly 5-ranked, straight to strongly curved, leaves moderately elongated at distal end.  Branch fascicles with 2 spreading and 1--2 pendent branches.  Branch stems green but sometimes reddish at proximal end, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate to narrowly ovate-lanceolate, 1.8--3.4 mm; straight to strongly subsecund; weakly undulate and recurved when dry; margins entire; hyaline cells on convex surface with 1--2 free pores per fibril interval, concave surface aporose or rarely with a few wall thinnings in cell ends and angles; chlorophyllous cells trapezoidal in transverse section and narrowly exposed on concave surface.  Sexual condition dioicous.  Spores 33--40 \um.

Varieties 5 (2 in the flora): North America, Eurasia.

 

1. Branch leaf hyaline cells on convex leaf surface with 1--2 pores per fibril interval, these usually less than 1/3 the cell diameter.. 36a.   Sphagnum majus subsp. majus

1. Branch leaf hyaline cells on convex leaf surface with 1 pore per fibril interval, these more than 1/3 the cell diameter............ 36b.   Sphagnum majus subsp. norvegicum

 

36a.  Sphagnum majus   (Russow) C. E. O. Jensen subsp. majus    F

Sphagnum dusenii Russow & Warnstorf

Plants golden brown to dark brown; branches strongly laterally curved.  Stem leaves 0.8--1.3 mm, usually appressed.  Branch leaves 2--2.8 mm, straight to usually strongly subsecund; hyaline cells on convex surface often with 2 pores per fibril interval, pores usually less than 1/3 cell diameter.  Spores 33--38 \um; both surfaces roughly verrucate scabrate; proximal laesura less than 0.5 spore radius.

Forming wet carpets but habitat unclear due to recent taxonomic separation from Sphagnum majus subsp. norvegicum; in North America, S. majus seems to occur in ombrotrophic to poor fen habitats, often on floating mats, mixed with S. cuspidatum in eastern North America; B.C.**c**, Nfld. and Labr. (Nfld.), N.S., Ont.**c**, Que.**c**; Alaska**w**, Conn., Maine, Mass., Mich., Minn., N.H., N.J., Pa., Vt., Wis.; Eurasia.

Sporophytes are rare.  In the field Sphagnum majus subsp. majus is typically darker brown than subsp. norvegicum, while its capitulum is denser and less stellate appearing than the latter species.  See also discussion of 23. S. annulatum.

 

36b.  Sphagnum majus   subsp. norvegicum   K. I. Flatberg, K. Norske Vidensk. Selsk. Skr. 2: 1.  1987    F

Plants green, yellow-green, brownish green to golden-brown; branches straight to slightly curved.  Stem leaves 1--1.4mm, often spreading.  Branch leaves 1.8--3.4 mm, straight to slightly subsecund; hyaline cells on convex surface with mostly 1 pore per fibril interval, pores more than 1/3 cell diameter.  Spores 33--40 \um; distal surface finely and densely granulate.

Habitat unclear due to recent taxonomic separation from Sphagnum majus subsp. majus (K. I. Flatberg 1987); in North America, S. major subsp. norvegicum seems to occur in weakly minerotrophic habitats such as poor sedge fens, lake edges, and floating mats; Alta.**n**, B.C.**c**, Nfld. and Labr. (Nfld.), N.W.T.**s**, N.S., Ont.**s**, Que.**s**, Sask.**n**, Yukon**s**; Alaska**c**, Conn., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., Pa., Wis.; Eurasia?

Sporophytes uncommon.  See discussion of 23. Sphagnum annulatum.  Spore features are taken from from K. I. Flatberg (1987).

 

37.  Sphagnum mcqueenii   R. E. Andrus, SIDA    E     {{to be published this year}}

Plants robust and weak-stemmed; yellow to light brown; capitulum flat-topped and with +/- conspicuous terminal bud.  Stems light green; superficial cortex of 1--2 layers of moderately differentiated thin-walled cells.  Stem leaves equilateral triangular, 0.8--1.1 mm; often spreading; apex more or less obtuse; leaves often spreading; hyaline cells usually septate and often fibrillose in proximal half of leaf.  Branches unranked, +/- straight, leaves moderately elongated at distal end.  Branch fascicles with 2 spreading and 1--2 pendent branches.  Branch stems green, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate, less than 2.2 mm, straight; undulate and sharply recurved when dry; margins entire; hyaline cells on convex surface with 0--1 apical pores and often with pseudopores, concave surface with to 12 round wall thinnings in cell angles and sometimes along commissures; chlorophyllous cells triangular in transverse section, just enclosed on the concave surface and broadly exposed on the convex surface.  Sexual condition unknown.  Spores not seen.

Habitat poorly understood, but known from floating mats in poor fen habitats; Nfld  and Labr. (Nfld.); N.H., Pa.

Sporophytes for Sphagnum mcqueenii are unknown. Sphagnum torreyanum and S. atlanticum both have longer, narrower and less sharply recurved branch leaves than S. mcqueenii.  Both S. cuspidatum and S. viride have acute stem leaves as compared to the obtuse stem leaves of this species.  Sphagnum pulchrum has 5-ranked branch leaves and apiculate stem leaves, which contrast strongly with the unranked branch leaves and obtuse stem leaves of this species.

 

38.  Sphagnum mendocinum   Sullivant, Icones Musc. Suppl., 12.  1874    E

Sphagnum mendocinum var. gracilescens; S. mendocinum var. recurvum Röll; S. mendocinum var. robustum Warnstorf;

Plants moderately robust and lax; terminal bud somewhat enlarged; yellow-green to light brownish green.  Stems yellow-green; superficial cortex of 1--2 layers of moderately enlarged cells.  Stem leaves broadly oblong-triangular, 1.2--1.5 mm; mostly appressed to stem; apex obtuse; hyaline cells narrow, usually nonseptate, efibrillose and aporose on convex surface near apex, on concave surface usually efibrillose with irregular pores along commissures in distal portion of leaf.  Branches with loosely imbricate leaves; often 5-ranked; leaves little to somewhat elongated at distal end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems green, with cortical cells in 1 layer with conspicuous necks.  Branch leaves ovate, ovate-lanceolate to lanceolate; 2--3.5 mm; flat and undulate at margins and recurved at apex when dry; straight; margins entire; hyaline cells on concave surface with very numerous, small ringed or unringed pores along the commissures, 5--12 in distal portion of leaf and 20--27 in proximal portion, convex surface with 5--15 pores per cell in distal portion of leaf and 14--21 in proximal portion, pores usually without a ring; chlorophyllous cells triangular to trapezoidal in transverse section and exposed slightly on concave surface.  Sexual condition dioicous.  Spores ca 30 \um; very slightly roughened.

Submerged or floating in weakly minerotrophic wet depressions of alder swamps, coniferous swamps, Spiraea thickets, sedge fens, raised bogs, and drainage ditches in mires; B.C.**c**; Alaska**PH**, Calif., Idaho, Mont., Oreg., Wash.  

Sporophytes are uncommon.  Although the unique branch leaf porosity of Sphagnum mendocinum makes it unmistakable microscopically, it may be confused with other species in the field.  The species is unusual ecologically in that it seems to overlap both the carpet and lawn forming habits---in other words it seems intermediate between Sphagnum recurvum s.l. and S. cuspidatum s.l. Among the species that it overlaps floristically, it is more robust and darker colored than S. pacificum.  The latter also has an apiculate stem leaf compared to the more or less obtuse stem leaves of S. mendocinum.  The more wet-growing S. majus and S. norvegicum, with which it slightly overlaps in habitat, have branch leaves that are strongly elongated at the distal branch ends whereas those of S. mendocinum are not. See also discussion of S. obtusum.  Sexual condition and spore characters are taken from from H. A. Crum (1984).

 

39.  Sphagnum mississippiense   R. E. Andrus, Mem. New York Bot. Gard. 45: 237.  1987 (as mississippiensis)    E

Plants small, short and weak-stemmed, compact and sprawling in thin mats, green to pale yellow.  Stems green, superficial cortex of thin-walled but not much enlarged or differentiated.  Stem leaves elongate-triangular, 1.3--1.5 mm; often spreading; apex obtuse; hyaline cells mostly efibrillose and 1--septate in proximal half and lateral portions of leaves.  Branches unranked, often blunt and with leaves moderately elongated at distal end.  Branch fascicles with 2--3 spreading and 0--2 pendent branches.  Branch stems green, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate to broadly ovate at branch base and becoming ovate-lanceolate at branch tip; 1.2--1.5 mm; undulate when dry, margins serrulate; hyaline cells of convex surface with 0--5 pores or pseudopores at cell apex, concave surface with faint round wall thinnings in cell angles, but may be absent, chlorophyllous cells trapezoidal in transverse section, exposed more broadly on convex surface.  Sexual condition probably dioicous? Spores not seen.

Mats in seasonally wet depressions in coastal plain; La., Miss., N.J.  

Sporophytes are unknown.  The combination of broad branch leaves and obtuse stem leaves will distinguish this species from Sphagnum cuspidatum and S. viride.  The much commoner and more wide-ranging S. trinitense, although also having serrulate branch leaves, has much narrower branch leaves that are more elongate at the branch tips, becoming quite lanceolate as compared with the ovate-lanceolate branch leaves that S. mississippiense exhibits at its branch tips.

 

40.  Sphagnum obtusum   Warnstorf, Bot. Zeit. 35: 478.  1877

Plants moderate to robust, weak-stemmed, yellow, yellowish brown to golden brown; capitulum varying from rounded, not 5-radiate and twisted to flat 5-radiate and straight branched.  Stem pale green to pale brown; superficial cortex of weakly to moderately differentiated.  Stem leaves triangular-lingulate, 0.9--1.3 mm; usually appressed; apex obtuse and often erose; hyaline cells efibrillose and nonseptate.  Branches tapering or in more robust forms, frequently blunt, straight to arcuate, leaves slightly to moderately elongated at distal end.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems green, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate to ovate-lanceolate; more than 1.8 mm; straight, stiff, not much undulate and reflexed to recurved; margins entire; hyaline cells on convex surface with a few end pores, but mostly numerous small to very small (often barely visible) pores or wall thinnings free from the commissures, on concave surface similar, but with pores generally fewer and larger; chlorophyllous cells triangular in transverse section, just reaching concave surface or slightly enclosed.  Sexual condition dioicous.  Spores 18--27 \um; both surfaces covered with rough, irregular verrucate plates of papillae, bifurcated Y-mark sculpture on distal surface; proximal laesura less than 0.5 spore radius.

Forming carpets in minerotrophic peatlands; Greenland**s**; Alta.**c**, B.C.**n**, Man.**n**, Nfld. and Labr. (Nfld.), N.W.T.**c**, Nunavut**c**, Ont.**n**, Que.**c**, Sask.**n**, Yukon,**c**; Alaska**c,AI,PH**, Minn.; Eurasia.

Sporophytes are uncommon in Sphagnum obtusum.  This is a quite phenotypically variable species that warrants further investigation, which may result in taxonomic splitting.  The strongly obtuse stem leaf should separate it from any similar species with which it occurs.  Sphagnum mendocinum looks similar phenotypically but there appears to be no range overlap with S. obtusum.  The tiny branch leaf pores, which may seem like no more than pinpricks in the cell surface, separate S. obtusum easily microscopically from other species of sect. Cuspidata.

 

41.  Sphagnum pacificum   Flatberg, Bryologist 92: 116, figs. 1--20.  1989    E

Plants moderate-sized and fairly strong-stemmed; green, yellow to yellowish brown; capitulum 5­-radiate in shade forms to hemispherical in open grown or drier growing forms.  Stems pale green to pale brown, sometimes with red branch bases; superficial cortex of 2 layers of enlarged, clearly differentiated and thin-walled cells.  Stem leaves triangular to lingulate-triangular, 0.8--1.3 mm; typically appressed; apex acute to apiculate; hyaline cells efibrillose and nonseptate to rarely septate.  Branches straight and somewhat tapered, usually 5-ranked; leaves little elongate at the distal branch end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems green but often reddish at proximal end, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate to narrowly ovate-lanceolate; (1.1--)1.4--1.8(--3.1) mm; slightly undulate and sharply recurved when dry, somewhat subsecund; margins entire; hyaline cells on convex surface with usually 1 round pore on apical end, on concave surface with wall thinnings in the cell ends and angles; chlorophyllous cells broadly triangular in transverse section and very deeply enclosed on the concave surface.  Sexual condition dioicous.  Spores 19--25 \um; finely papillose on both surfaces.

Forested and open poor fen habitats, often as a ruderal species in extensive mats; B.C.**c**; Alaska**s,AI,PH**, Oreg., Wash.  

Sporophytes in Sphagnum pacificum are uncommon.  See discussion of 26. S. brevifolium.  Characters of the spores are taken from K. I. Flatberg (1989).

 

42.  Sphagnum pulchrum   (Lindberg) Warnstorf, Bot. Centralbl. 82: 42.  1900

Sphagnum intermedium var. pulchrum Lindberg in R. Braithwaite, Sphagnac. Eur., 81, frg. 25g.  1880

Plants moderate-sized to robust, often quite dense and compact; green, brownish green, golden-brown to dark brown; capitulum flat-topped and not especially 5-radiate.  Stems green to dark brown; superficial cortex of 2 layers of enlarged, moderately differentiated cells.  Stem leaves triangular to triangular-lingulate, 0.9--1.1 mm; appressed to spreading; apex apiculate, acute or narrowly obtuse, appressed to spreading; hyaline cells nonseptate and efibrillose.  Branches straight to more typically curved, typically stout and blunt ended; strongly 5-ranked, leaves not much elongate at distal end, Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems green but often reddish at proximal end, with cortex enlarged with conspicuous retort cells.  Branch leaves ovate to ovate-lanceolate, 1.4--1.8 mm; straight to often subsecund; weakly undulate and slightly recurved; hyaline cells on convex surface with 1 pore per cell at apical end of cell, on concave surface with round wall thinnings in the cells ends and angles; chlorophyllous cells triangular to triangular-ovate in transverse section, very well-enclosed within concave surface.  Sexual condition dioicous.  Spores 25--28 \um; roughly papillous on both surfaces; proximal laesura more than 0.5 the length of the spore.:

Abundant in poor fens and raised bogs, forming dense carpets at water level, especially on floating mats; Man **s**, N.B., Nfld. and Labr. (Nfld.), N.S., Ont.**c**, Que.**c**; Alaska**w**, Conn., Ind., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., Wis., W.Va.; Europe.

Sporophytes are uncommon in Sphagnum pulchrum. With its distinctive broad and strongly 5-ranked branch leaves, S. pulchrum is one of our most easily recognized species.

 

43.  Sphagnum recurvum   P. Beauvois, Prodr. Aetheog., 88.  1805

Sphagnum pentastichon Bridel; S. pulchricoma J. K. A. Müller; S. riparioides Warnstorf

Plants moderate-sized to robust, moderately stiff-stemmed, +/- lax, but not compact; green to pale yellow to yellowish brown; capitulum typically strongly convex in open grown forms, but flat and +/- 5-radiate in shade forms.  Stem pale green to yellowish; superficial cortex of 2 layers of enlarged, thin-walled and well differentiated cells.  Stem leaves triangular, triangular-lingulate to lingulate, more than 0.8 mm, appressed, apex obtuse to broadly obtuse, erose to fimbriate; hyaline cells efibrillose and nonseptate.  Branches straight and often tapering, often 5-ranked, leaves not much elongate at distal end of branches.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems green, cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate, 1.4--2 mm, straight; slightly undulate and sharply recurved; margins entire; hyaline cells on convex surface with 1 pore per cell at cell apex, concave surface with round wall thinnings in the cell ends and angles; chlorophyllous cells triangular in transverse section and well-enclosed on concave surface.  Sexual condition dioicous.  Spores 22--28 \um; papillose on both surfaces; proximal laesura more than 0 5 spore radius.

Capsules mature late summer to early fall.  Forming carpets in a variety of very poor to poor fen habitats, including sedge fens, pocosins, bay swamps; Nfld. and Labr. (Nfld.), N.S.; Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Tex., Vt., Va., W.Va.; South America.

Sporophytes in Sphagnum recurvum are uncommon.  This species is exclusively New World. It has several strong characters that distinguish it from S. flexuosum, and the opinion of H. A. Crum (1997) that the two species are synonymous is rejected.  See discussion of S. flexuosum.

 

44.  Sphagnum riparium   Ångstrom, Ofv. Sv. Vet.-Akad. Forh. 21: 198.  1864

Plants stiff and upright, large; green to pale green to brownish, capitulum large and flat, with a conspicuous terminal bud.  Stems pale green, superficial cortex of 3--4 layers of weakly differentiated cells.  Stem leaves triangular-lingulate, 1.2--1.4 mm; apex with a deep lacerate split; hyaline cells aporose, efibrillose and often septate.  Branches unranked to rarely 5-ranked, branch leaves only weakly undulate, but sharply recurved at the apex, leaves not much elongated at distal end.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stem green, cortex enlarged with retort cells.  Branch leaves ovate-lanceolate; 2--2.6 mm; straight; weakly undulate but strongly recurved, hyaline cells on convex surface with very large irregular pores (formed from the confluence of several smaller pores) at the cell apex, concave surface with large round wall thinnings in the cell angles; chlorophyllous cells triangular to trapezoidal in transverse section, apex normally slightly exposed on concave surface.  Sexual condition dioicous.  Spores 22--28 \um; proximal surface noticeably papillose, distal surface smooth or with fewer papillae; proximal laesura more than 0.5 the length of the radius.

Forming often extensive carpets in weakly minerotrophic mires; Greenland**s**; Alta.**c**, B.C.**c**, Man.**c**, N.B., Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Ont.**c**, P.E.I., Que.**c**, Sask.**n**, Yukon,**c**; Alaska**c,AI,PH**, Conn., Ind., Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Y., Ohio, Pa., Vt., Wash.; Eurasia.

Sporophytes are uncommon in Sphagnum riparium.  This species is typically very easily recognized in the field with its pale green color, strong terminal bud and unranked branch leaves.

 

45.  Sphagnum rubroflexuosum   R. E. Andrus, Bryologist 91: 364, figs. 1--8.  1988    E

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; capitulum and along stem; loose to somewhat compact.  Stems pale green to pink; superficial cortex of undifferentiated.  Stem 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 moderately long and tapering, unranked to weakly 5-ranked, leaves not much elongated at distal end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stem cortex enlarged and with conspicuous retort cells.  Branch leaves 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 unknown.  Spores not seen,

Forming carpets in weakly minerotrophic fens; Md., Pa.  

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.

 

46.  Sphagnum splendens   Maass, Bryologist 70: 193, figs. 1--4.  1967    E

Plants moderate-sized, pale brown and shiny, capitulum well defined.  Stems yellowish, superficial cortex of moderately well differentiated.  Stem leaves triangular, 0. 7--0. 9 mm, appressed to stem; apex apiculate; hyaline cells efibrillose and nonseptate.  Branches moderately tapering, leaves only moderately larger at branch tips.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems green; cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate, 1--1.4 mm; straight; stiff, not undulate and slightly recurved; margins entire; hyaline cells efibrillose, convex surface with 1 pore per cell at cell apex, on concave surface with round wall thinnings in the cell ends and angles; chlorophyllous cells triangular in transverse section and well enclosed to just reaching concave surface.  Sexual condition unknown.  Spores unknown.

Known only from the type locality; w Que.**c**.  

Sporophytes of this species are unknown.  The lack of any fibrils in the branch leaf hyaline calls gives Sphagnum splendens an unusually glossy appearance that should make it readily identifiable in the field.  The fact that it differs from S. fallax only in one character as well as it being known only from the type locality makes S. splendens a questionable taxon to some observers.  More investigation is needed.

 

47.  Sphagnum tenellum   (Bridel) Bory, Voy. Iles Afr. 3: 107.  1804    

Sphagnum cymbibolium var. tenellum Bridel, Musc. Recent. 2(1): 24.  1798; S. molluscum Bruch

Plants small, slender and weak-stemmed; pale yellow to golden-brown, rarely tinged with red; capitulum not especially distinct.  Stems pale green to pale brown; superficial cortex of 2--3 layers of enlarged thin-walled cells.  Stem leaves ovate-lingulate; 1--1.3 mm, apex broadly rounded; hyaline cells nonseptate, aporose and fibrillose in at least distal half of leaf.  Branches 2--3 spreading and 2 pendent leaves not much elongated at distal end.  Branch stems green; cortex enlarged, with conspicuously long-necked retort cells.  Branch leaves ovate, 1--1.5 mm; straight; not or weakly undulate or recurved when dry; margins entire; hyaline cells short and wide, convex surface with 1--3 small pores per cell and on concave surface with large round wall thinnings in the cell angles; chlorophyllous cells equilateral-triangular in transverse section, broadly exposed on convex surface and just reaching to well-enclosed on concave surface.  Sexual condition monoicous.  Spores 27--42 \um; both surfaces smooth, proximal surface with distinct bifurcated Y-mark sculpture surrounded by distinct circular border, distal surface with distinct raised border around margins; proximal laesura usually less than 0.4 spore radius.

Capsules mature early to mid-summer.  Wet depressions in a variety of ombrotropic and weakly minerotrophic habitats; Greenland**s**; B.C.**c**, Man.**n**, N.B., Nfld. and Labr. (Nfld.), N.S.; Alaska**c, ,AI,PH**, Maine, N.J., N.Y., N.C.; Eurasia. 

Sporophytes are common in Sphagnum tenellum.  The delicate appearance created by the ovate and concave branch leaves as well as the large concave stem leaves make this a usually unmistakeable species.

 

48.  Sphagnum torreyanum   Sullivant, Mem. Amer. Acad. Arts Sci. n. s. 4: 174.  1849    E

Sphagnum cuspidatum var. torreyi Braithwaite; S. cuspidatum var. miquelonense (Röll) Renauld & Cardot; S. kearneyi Warnstorf; S. laxifolium var. miquelonense Röll

Plants robust and weak-stemmed; green to golden-yellow; capitulum +/- rounded in emergent forms, flat in submersed forms; lacking distinct terminal bud.  Stems green to brown; superficial cortex of 2 layers of thin-walled and enlarged cells.  Stem leaves triangular, 1--1.7 mm, apex acute to slightly obtuse; leaves usually appressed; margins entire; hyaline cells fibrillose and usually septate at base and sides.  Branches unranked, long and tapering, leaves greatly elongated at distal end.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch stems green; cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate to lanceolate, 3--5.5 mm; straight but sometimes slightly falcate-secund; weakly undulate and recurved when dry; margins entire; hyaline cells on convex surface with 0--1 pore per cell, on concave surface with round wall thinnings on the apices and angles; chlorophyllous cells narrowly triangular in transverse section and just enclosed on the concave surface.  Sexual condition dioicous.  Spores 26--29 \um; both surfaces distinctly papillose, appearing pusticulate to irregularly pusticulate; proximal laesura mostly less than 0.5 spore radius.

Forming wet often floating carpets in weakly minerotrophic mires; St. Pierre and Miquelon (Miquelon); N.B., Nfld. and Labr. (Nfld.), N.S., Que.**c**; Ala., Conn., Del., Fla., Ga., La., Maine, Md., Mass., Miss., N.H., N.J., N.Y., N.C., Pa., S.C., Vt., Va.  

Sporophytes are uncommon in Sphagnum torreyanum.  See discussion of 24. S. atlanticum for taxonomic distinctions.

 

49.  Sphagnum trinitense   J. K. A. Müller, Syn. Musc. 1: 102.  1848

Sphagnum cuspidatum var. serratum (Austin) Austin; S. cuspidatum var. serrulatum (Schliephacke) Schliephacke; S. helleri Warnstorf; S. laxifolium var. serrulatum Schliephacke; S. serratum Austin

Plants moderate-sized, slender and weak-stemmed, green to pale yellow; flaccid and plumose in aquatic forms to more compact and sprawling in emergent forms; green to pale yellow; capitulum not especially enlarged and differentiated.  Stems green; superficial cortex of undifferentiated or nearly so.  Stem leaves ovate-triangular to triangular, 1--1.6 mm; appressed to spreading; apex acute to slightly obtuse; hyaline cells often fibrillose and often 1-septate.  Branches straight and unranked, in capitulum tapering at distal end to a point, leaves greatly elongated at distal end.  Branch stems green, cortex enlarged with conspicuous retort cells.  Branch leaves ovate-lanceolate to lanceolate, 2--3.5 mm; straight, undulate and slightly recurved when dry; margin serrulate; hyaline cells on convex surface with 0--1 small pores at cell apex on concave surface with round wall thinnings in cell angles (often indistinct or lacking); chlorophyllous cells trapezoidal in transverse section and exposed more broadly on the convex surface.  Sexual condition monoicous.  Spores 26--40 \um; +/- roughly to densely granulose.

Capsules mature early to mid-summer.  Submersed or stranded at edge of shallow, acidic pond, lakes, and roadside ditches, mostly in sandy areas of the Atlantic coastal plain; Del., Fla., Ga., Ill., Kans., La., Md., Mass., N.J., N.Y., N.C., Pa., S.C., Va.; South America.

Sporophytes are common in Sphagnum trinitense, which can often be distinguished from S. cuspidatum in the field by the appearance of its branches when wet.  In this state the branches of S. trinitense just below the capitulum resemble a fine paintbrush drawn out to a pointed tip.  See also under S. fitzgeraldii and S. mississippiensis.  Spore features are taken from from H. A. Crum (1984).

 

50.  Sphagnum viride   Flatberg, K. Norske Vidensk. Selsk. Skr. 1: 9, figs. 1--2, 6: a, 7, 15--16, 17: m--x, 18, 19: b, 20: b, 21: a,c, 22: k--x..  1988

Plants slender and weak-stemmed, moderate-sized, flaccid and plumose when submerged and stiffer and more compact when emergent; green to yellow, usually not tinged with brown or red; capitulum well defined, flat in submersed forms and more rounded in emergent forms.  Stems green; superficial cortex of 2--3 layers of enlarged thin-walled cells.  Stem leaves long triangular-ovate, 1--2 mm; usually appressed; apex acute to apiculate, hyaline cells only rarely septate or aporose but often fibrillose in apical region.  Branches unranked, straight to slightly curved, leaves somewhat elongated at distal end.  Branch fascicles with 2 spreading and 2--3 pendent branches.  Branch stems green, cortex enlarged with conspicuous retort cells.  Branch leaves 1.5--2.7 mm, ovate-lanceolate to lanceolate ; straight to falcate toward branch tips; when dry often undulate and lightly recurved, margins entire to rarely weakly toothed along the margins in flaccid aquatic forms, hyaline cells on convex surface with 0--1 small round pores at apex, on concave surface with faint round wall thinnings in cell apices and angles; chlorophyllous cells triangular to trapezoidal in transverse section, broadly exposed on the convex surface and exposed slightly to broadly on the concave surface.  Sexual condition dioicous.  Spores 30--43 \um; the superficial surface coarsely papillose to papillose reticulate.

Widespread, forming wet carpets in weakly minerotrophic mires; Nfld. and Labr. (Nfld.), N.S.; Ala., Conn., Del., Fla., Ind., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Vt., Va.; Europe.

The sporophytes of Sphagnum viride are uncommon.  See discussion of 27. S. cuspidatum for taxonomic distinctions.  Spore characters from K. I. Flatberg (1988).

 

1g.  Sphagnum   sect.  Subsecunda   (Lindberg) Schimper, Syn. ed. 2.  1876

Sphagnum [unranked] Subsecunda Lindberg, Öfv. Förh. Kongl. Svenska Vetensk.-Akad. 19:  1862; S. [unranked] Cavifolia C. E. O. Jensen; S. [unranked] Comatosphagnum J. K. A. Müller; S. [unranked] Cyclophylla Lesquereux & T. P. James; S. sect. Hemitheca Braithwaite

Plants erect to prostrate, extremely variable, capitulum rarely well-developed; green, yellowish, light brown, golden brown, reddish brown to dark brown.  Stem green to dark brown, superficial cortex of 0--3 layers of efibrillose, non-ornamented, enlarged, thin-walled cells; cells in outer layer aporose or with single round to elliptical wall thinning adjacent to the distal cell wall, visible only with heavy staining.  Stem leaves varying from smaller than to larger than branch leaves; triangular, ovate to lingulate; with rounded and sometimes erose apex; border entire; hyaline cells rhomboid to S-shaped, non-ornamented, efibrillose to fibrillose, aporose to sometimes porose, non- to multiply septate; neither surface resorbed.  Branches not always clearly dimorphic, spreading and pendent branches very similar.  Branch fascicles 1--3 spreading and 0--2(-4) pendent.  Branch stems green, surrounded by 1 layer of efibrillose, non-ornamented, thin-walled, inflated cells, with solitary short-necked retort cells or with conspicuously necked retort cells, interspersed with primarily aporose rectangular-shaped cells.  Branch leaves oval, ovate or ovate-lanceolate; hyaline cells fibrillose, non-ornamented; convex surface mostly with numerous elliptical to round pores (8--24 per cell) in rows along commissures on convex surface, concave surface with fewer or no pores; chlorophyllous cells elliptical in transverse section, +/- equally exposed on both surfaces or slightly more on convex surface, end walls not thickened.  Sexual condition dioicous.  Capsule with few pseudostomata.  Spores 22--41 \um, with or without raised surface sculpture on distal surface; proximal laesura more than 0.5 spore radius.

Species 99 (13 in the flora):   worldwide in distribution excepting Antarctica.

 

 

1.   Stem cortex undifferentiated, superficial layer composed of small thick-walled cells................................................. 57.   Sphagnum microcarpum

1.   Stem cortex differentiated with one or more superficial layers of enlarged thin-walled cells.

2.   Stem cortex of mostly 2--3 superficial layers of enlarged, thin-walled cells.

3.   Stem leaves broadly ovate and completely fibrillose, fascicles of 3 branches; terminal bud large, round.. 61.   Sphagnum platyphyllum

3.   Stem leaves lingulate and fibrillose apically; fascicles most 4 or more branches; terminal bud, if any, small.

4.   At least some stem leaf hyaline cells with 2 or more parallel septations; branch leaves 2.2--3 mm................ 51.   Sphagnum carolinianum

4.   Stem leaf hyaline cells without parallel septations, usually non-septate; branch leaves 1.2--2 mm... 52.   Sphagnum contortum

2.   Stem cortex of mostly 1 superficial layer of enlarged, thin-walled cells.

5.   Stem simple without branches.

6.   Hyaline cells of stem and branch leaves with numerous minute, rounded pores on free surface, stem and branch leaves similar and very large (3.5--4 mm), some stem cortical cells with a single wall thinning at the distal end of the cell.... 53.   Sphagnum cyclophyllum

6.   Hyaline cells of stem and branch leaves without pores on superficial surface or with 1--3 small pores in apical ends and angles of cells, stem leaves longer (1.5--2.5 mm) than branch leaves (0.9--1.2 mm), stem cortical cells aporose................. 62.   Sphagnum pylaesii (in part)

5.   Stems with branches arranged in fascicles.

7.   Hyaline cells of branch leaves without pores on convex surface or with 1--3 small pores in cell apical ends and angles, hyaline cells of branch leaves with thick fibrils that nearly divide the cells into a series of squarish segments.... 62.   Sphagnum pylaesii (in part)

7.   Hyaline cells of branch leaves with rows of commissural pores or with 1--5 pores per cell free from the commissures on the convex surface, hyaline cells with thin fibrils.

8.   Stem leaves greater than 1.2 mm, lingulate to ovate-lingulate, generally fibrillose for more than 1/3 their length.............. 56.   Sphagnum lescurii

8.   Stem leaves equal to or less than 1.2 mm, triangular to triangular-lingulate, generally fibrillose for 1/3 or less their length.

9.   Branch leaf hyaline cells lacking pores along the commissures but up to 5 small pores free from the commissures on convex surface............ 58.   Sphagnum oregonense

9.   Branch leaf hyaline cells with continuous rows of pores along the commissures and sometimes with few to numerous pores free from the commissures on convex surface.

10. Branch leaf hyaline cell pores less than or equal to 3 \um, often with 1--2 rows of pores free from the commissures.

11. Branch leaf hyaline cells on convex surface with tiny pores less than or equal to 1 \um, stem leaf hyaline cells with moderate to large pores in cell angles, plants pale yellow to gray-green and not shiny........................ 59.   Sphagnum orientale

11. Branch leaf hyaline cells with pores ca. 2 μm, stem leaf hyaline cells with small pores in rows, plants golden-brown to dark brown and shiny........................... 60.   Sphagnum perfoliatum

10. Branch leaf hyaline cell pores more than 3 μm, lacking pores free from the commissures.

12. Branch leaf hyaline cells on convex surface in discontinuous rows in the basal portion of the leaf, these often only in the cell ends and angles....................... 54.   Sphagnum inexspectatum

12. Branch leaf hyaline cell pores on convex surface in continuous rows in the basal portion of the leaf.

13. Stem leaves longer than 0.7 mm; branch leaves equal to or greater than 1.2 mm, mostly straight. 55.   Sphagnum inundatum

13. Stem leaves less than 0.7 mm; branch leaves less than 1.2 mm, often subsecund.......... 63.   Sphagnum subsecundum

 

51.  Sphagnum carolinianum   R. E. Andrus, Bryologist 86: 257, figs. 1--4, 11--15, 18, 19.  1983    E

Sphagnum subsecundum var. carolinianum (R. E. Andrus) H. A. Crum 

Plants moderate to large, erect to floating, green to dark brown; capitulum large, well defined and flat-topped.  Stems typically light green but grading to dark brown; superficial cortex of 2--3 layers of enlarged, thin-walled cells.  Stem leaves lingulate to lingulate-triangular, 0.7--1.5 mm (to 3 mm in isophyllous forms), apex erose; hyaline cells mostly 1--septate but in a few cells with 2--3 parallel septations, efibrillose to fibrillose throughout, pores present in hemiisophyllous and isophyllous forms.  Branches straight to somewhat curved, with spreading leaves.  Branch fascicles with 2 spreading and 2 pendent in emergent forms, these reduced in aquatic forms to 2 per fascicle.  Branch leaves variable, broadly ovate to ovate-lanceolate, 1.3--5 mm; straight, hyaline cells on the convex surface with 4--8 μm round to elliptic pores in nearly continuous rows along the commissures, the concave surface aporose or with some porosity as on the convex surface.  Sexual condition unknown.  Capsule not seen.  Spores not seen.

Forming wet often floating carpets in pools in weakly minerotrophic mires; Nfld. and Labr. (Nfld.); Ala., Del., Fla., Ga., La., Maine, Mass., Miss., Mo., N.J., N.Y., N.C., S.C., Tenn., Tex., Va.  

The sporophytes of Sphagnum carolinianum are unknown.  In its apparent restriction to the coastal plain, this species is most similar distributionally to such species as S. macrophyllum, S. fitzgeraldii, and S. tenerum.  When forming carpets, S. carolinianum macrospically most resembles S. atlanticum but its branch leaves are not as elongate as the latter and its stem leaves have a much more obtuse apex.  When growing aquatically, S. caroliniaum can resemble S. cribrosum, but in the latter species the hanging branches are not different from the spreading branches and may even be lacking.

 

52.  Sphagnum contortum   Schultz, Prodr. Fl. Starg. Suppl., 64.  1819

Plants moderate to small-sized, weak-stemmed to spawling; green, yellow-green to golden-brown; capitulum usually large and flat with curved branches; green, yellow-green, or golden brown.  Stems pale green to light brown, rarely dark brown; superficial cortex of 2--3 layers of enlarged, thin-walled cells.  Stem leaves triangular-lingulate to lingulate, 0.7--1.4 mm; apex rounded-obtuse and weakly denticulate; hyaline cells nonseptate, mostly efibrillose, and, if porose, with more pores per cell on the concave surface (3--6) than on the convex surface (0--2).  Branches somewhat curved, leaves spreading.  Branch fascicles with 2--3 spreading and 2--3(4) pendent branches.  Branch leaves ovate to ovate-lanceolate, 1.2--2 mm; subsecund; hyaline cells with numerous tiny pores in a continuous line along the commissures on the convex surface, no or scattered pores on the concave surface.  Sexual condition dioicous.  Capsule exserted, with scattered pseudostomata.  Spores 22--28 \um; papillose on both surfaces; proximal laesurae more than 0.5 spore radius.

Very minerotrophic, sometimes found in slightly basic mires; intolerant of shade; Alta.**n**, B.C.**n**, Nfld. and Labr. (Nfld.), N.S., Ont.**c**, Que.**c**; Alaska**s,PH**, Calif., Colo., Conn., Idaho, Ill., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., Vt., Wash., W.Va., Wis.; Eurasia.

Sporophytes are rare in Sphagnum contortum.  This species is often associated with S. warnstorfii, S. centrale, Campylium stellatum, and Calliergonella cuspidata.  The relatively small size, curved capitulum branches and loosely spreading, subsecund branch leaves separate this species out along with S. subsecundum.  See also discussion of S. platyphyllum.

 

53.  Sphagnum cyclophyllum   Sullivant in A. Gray, Man. ed. 2,  611.  1856.

Plants low, erect or procumbent, loosely tufted; green or more frequently yellowish, orangish brown-red, reddish brown or dark red; capitulum not developed.  Stems brown to black; superficial cortex of 1 (--2) layers of enlarged, thin-walled cells.  Stem leaves broadly ovate, 3.5--4 mm, apex rounded and indistinctly toothed; hyaline cells on convex surface with 10--20 small (2.5--7.5 microns) round pores approximately 1/6 the diameter of the hyaline cells along the commissures, cells on concave surface uniporose in distal end or aporose, sometimes one or a few pores are scattered over the surface of the cells.  Branches few, single and short or more commonly none.  Branch fascicles, if any, usually only 1 single branch.  Branch leaves if any, are usually slightly smaller, 2--3 mm, but otherwise identical to the stem leaves.  Sexual condition dioicous.  Capsule immersed in perichaetial leaves, pseudopodium extremely short, without pseudostomata.  Spores 25--40 \um; coarsely papillose on both surfaces; proximal laesura more than 0.5 the length of the spore

Bare sand in places that are usually submerged for a portion of the year, in open grassy savannas, pine barrens, ditches; N.S.; Ala., Fla., Ga., La., Miss., N.J., N.C., S.C., Tenn., Tex., Va.; South America.

Sporophytes are quite rare in Sphagnum cyclophyllum.  This species grows associated with S. pylaesii, S. perichaetiale, S. portoricense, and S. lescurii.  Sphagnum pylaesii is the only other  North American Sphagnum that regularly grows unbranched.  The latter species not only lacks the typical sect. Subsecunda branch leaf porosity of S. cyclophyllum but is also much slenderer.  Sphagnum pylaesii is also much more likely to occur submersed, where it occurs in branched forms, something S. cyclophyllum rarely does.  See also discussion of S. microcarpum and S. platyphyllum.

 

54.  Sphagnum inexspectatum   Flatberg, Lindbergia 30: 59. 2005  E   

Sphagnum subsecundum var. andrusii H. A. Crum; S. subsecundum var. junsaiense (Warnstorf) H. A. Crum.

Plants moderate-sized, normally erect; yellowish to reddish brown, greenish in shaded forms; capitulum moderately distinct and rounded.  Stems dark brown; superficial cortex of 1(--2) layers of thin-walled enlarged cells.  Stem leaves triangular-lingulate to ovate-lingulate, 0.9--1.5 mm, apex rounded, straight; hyaline cells mostly non-septate, fibrillose in distal 1/3--2/3 of leaf, a few ringed pores at corners of cells and along commissures on convex surface, ringed pores along the commissures on the concave surface usually in greater numbers than on convex surface.  Branches short, not turgid.  Branch fascicles with 2--3 spreading and 1--2 pendent branches.  Branch leaves broad-ovate to ovate-lanceolate, 0.9--2.6 mm, straight; hyaline cells with numerous ringed pores (10--20) along the commissures on the convex surface, these reduced to cells angles and ends only at the base of the leaf, a few pseudopores and ringed pores (less than 8 per cell) occur on the cell angles on the concave surface.  Sexual condition dioicous.  Capsule exserted, with few pseudostomata.  Spores 36--39 \um; coarsely papillose on both surfaces; proximal laesura less than or equal to 0.5 spore radius.

Ecology unclear, but growing in carpets in depressions, blanket mires; B.C.**n**; Alaska**s,AI,PH**.  

This species is frequently collected with Sphagnum tenellum, S. pacificum, S. andersonianum, and S. rubellum in weakly minerotrophic blanket mires.  It is similar in size to S. subsecundum, with which its range completely overlaps.  The latter species has many of the branch leaves subsecund while those of S. inexspectatum are straight.  The stem leaves of S. inexspectatum are also conspicuously larger than those of S. subsecundum.

 

55.  Sphagnum inundatum   Russow, Arch. Nat. Dorpat 2, 10: 390.  1894

Sphagnum auriculatum var. inundatum (Russow) M. O. Hill; S. bavaricum Warnstorf?; S. bushii Warnstorf & Cardot?; S. novo-foundlandicum Warnstorf; S. subsecundum var. inundatum (Russow) C. E. O. Jensen

Plants moderate-sized, green in the shade to variegated yellow or orange or both in open habitats; capitulum typically rounded.  Stems green to brownish or yellow; superficial cortex of 1 layer of enlarged, thin-walled cells.  Stem leaves lingulate to triangular-lingulate, 0.9--1.2 mm, apex rounded, usually 1/3--1/2 of leaf fibrillose; hyaline cells usually fibrillose in distal 1/3--1/2 of leaf, on convex surface near apex with 1--3 pores per cell, on concave surface near apex 1--4 pores per cell.  Branches arched but rarely curved and contorted.  Branch fascicles with 2--3 spreading and 2--3 pendent branches.  Branch leaves ovate, 1--1.5 mm, straight to slightly subsecund; hyaline cells of convex surface with numerous ringed pores along the commissures (12--22 per cell), 0--3 pores per cell on the concave surface.  Capsule with few pseudostomata.  Spores 30--37 \um; finely papillose on both surfaces, indistinct raised Y-shaped sculpture on distal surface; proximal laesura 0.5 spore radius or less.

Weakly minerotrophic habitats such as the margins of ponds, marshes, and mires, in addition to seeps and dripping cliff faces; B.C.**c**, N.B., Nfld. and Labr. (Nfld.), N.S., Que.**s**; Alaska**s,AI,PH**. Conn., Del., Ky., Maine, Mass., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Vt., Va., W.Va.; Eurasia.

The sporophytes of Sphagnum inundatum are uncommon.  The ovate, concave branch leaves that are occasionally subsecund give this species an appearance similar to that of S. subsecundum, from which it can usually be distinguished by its larger size.  Sphagnum lescurii typically has distinctly larger stem leaves and capitulum branches that can be quite turgid and curved in open-grown forms.

 

56.  Sphagnum lescurii   Sullivant in A. Gray, Man. ed. 2. 611.  1856

S. alabamae Warnstorf?; S. aquatile Warnstorf?; S. auriculatum Schimper?; S. denticulatum Bridel?; S. obesum (Wilson) Warnstorf?; S. orlandense Warnstorf; S. plicatum Warnstorf; S. rufescens (Nees & Hornschuch) Warnstorf?; S. turgidulum Warnstorf?; S. wieboldtii H. A. Crum

Plants moderate-sized to robust; upright, prostrate, or aquatic; green, pale yellow, golden-brown, dark brown, tinged with red in exposed sites and purplish in aquatic forms; capitulum rounded and often strongly twisted.  Stems pale green to brown, darker in aquatic forms; superficial cortex of 1 layer of enlarged, thin-walled cells.  Stem leaves lingulate to ovate-lingulate, 1.3--2 mm; apex truncate to rounded, usually denticulate; hyaline cells typically fibrillose for 1/2 of leaf or more, often 1-2 septate, convex surface with 4--12 or more pores per cell along the commissures, concave surface with fewer pores.  Branches usually curving, often large and tumid.  Branch fascicles with 2(rarely 3) spreading and 1--2(3) pendent branches.  Branch leaves broadly ovate to ovate-lanceolate, 1.3--2.5 mm, greatly elongated in aquatic forms, straight or infrequently subsecund or subsquarrose; hyaline cells with 10--22 pores along the commissures on the convex surface, no or fewer pores per cell (1--8) on the concave surface.  Sexual condition dioicous.  Capsule exserted, with few pseudostomata.  Spores 27--34 \um; finely papillose on both surfaces, with distinct raised Y-mark sculpture (indistinctly bifurcated Y mark) on the distal surface; proximal laesura less than 0.5 spore radius.

Weakly minerotrophic in a broad range of wetlands, often of an aquatic or periodically dried character; Nfld. and Labr. (Nfld.), N.S.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., Wis., W.Va.; Europe.

Sporophytes are uncommon in Sphagnum lescurii, which may be the most phenotypically variable of all the North American Sphagna, and quite probably deserves some taxonomic splitting.  The tremendous phenotypic plasticity of this species, however, makes it quite difficult to sort out the genotypic component of variability, and thus most sphagnologists since Warnstorf have avoided the temptation of splitting and have instead treated this as one very variable species.  This is the approach maintained in this treatment.  We have also chosen not to use the earlier name S. denticulatum because the type of this species is a phenotypic morphotype not clearly assignable to the current concept of either S. auriculatum or S. lescurii (K. I. Flatberg, personal communication).  Some of the American material assignable to S. lescurii is quite likely the same as the European species S. auriculatum, but much of our material is certainly not the same.  Until more definitive data is available we have chosen to continue to use the name S. lescurii.  The large stem leaf will generally distinguish this from similar sect. Subsecunda species. See also discussion of S. inundatum and S. platyphyllum.

 

57.  Sphagnum microcarpum   Warnstorf, Hedwigia 47: 94.  1907    E    F

Sphagnum microcarpum var. humile Warnstorf; S. mobilense Warnstorf?

Plants small; green to light green, capitulum indistinct.  Stems green to dark brown; superficial cortex of nearly undifferentiated.  Stem leaves isophyllous, ovate to ovate-lanceolate, 2.2--2.8 mm; apex rounded; hyaline cells nonseptate, convex surface with 6--12 pores per cell along commissures, concave surface aporose.  Branches straight and short.  Branch fascicles nearly all with 2 spreading branch only.  Branch leaves ovate, 1.3--1.7 mm; hyaline cells on convex surface with 8--18 elliptic pores more than 8 \um, concave surface aporose.  Sexual condition unknown.  Capsule not seen.  Spores not seen.

Ruderal sites such as dessication-prone depressions, ditches, tire tracks, and natural depressions among tussocks; Fla., La., N.C.  

Sporophytes are rare in Sphagnum microcarpum.  This species grows over bare soil in a manner similar to that of S. cyclophyllum and S. fitzgeraldii.  It is now recognized as separate from S. cyclophyllum, with which it has been treated as synonymous in the past.  Besides the microscopic differences, S. microcarpum has a compact upright growth form quite unlike typical S. cyclophyllum.  Sphagnum microcarpum is nearly always branched whereas S. cyclophyllum is nearly always simplex.

 

58.  Sphagnum oregonense   Andrus, Bryologist 110: ---.  2007  E    {{to be published  in 2007}}

Plants small, green to light brown; capitulum moderately well defined.  Stems green; superficial cortex of 1 layer of well-differentiated, enlarged and thin-walled cells.  Stem leaves lingulate, 1--1.2 mm, apex entire to somewhat erose; hyaline cells non-septate; fibrillose and porose in apical region.  Branches slender with small spreading leaves.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch leaves ovate-lanceolate, 1.4--1.6 mm, straight to slightly subsecund, weakly undulate, often recurved in capitulum branches; hyaline cells on convex surface with up to 5 small round faint pores per cell in the basal portion of the cell and free from the cell margins, concave surface aporose.  Sexual condition unknown.  Capsule not seen.  Spores not seen.

Currently known only from the type locality where it occurs in a high elevation fen; Oreg.  

Sporophytes are unknown for Sphagnum oregonense.  This taxon is commonly associated with other minerotrophic bryophytes such as Messia triquetra, Calliergon cordifolium, and Campylium polygamum.  This is a curious species that has an obvious close relationship with sect. Cuspidata.  When wet it is similar in appearance to S. subsecundum but upon drying the sightly undulate and recurved branch leaves give it the charactereistic appearance of this section.  The branch leave porosity is also more similar to that of species in sect. Cuspidata than sect. Subsecunda.

 

59.  Sphagnum orientale   L. I. Savicz, Not. Syst. Sect. Crypt. Inst. Bot. Komar. Acad. Sci. URSS 7: 206.  1951    F

Plants pale yellow-brown, grey-green, to pale brown; not shiny when dry.  Stems green to brownish; superficial cortex of 1 sometimes irregularly 2 layers of inflated, thin-walled cells.  Stem leaves triangular-lingulate to lingulate; 0.7--0.8 mm; apex rounded and often erose, hyaline cells nonseptate or sometimes 1-septate, numerous small round pores more than 2 \um along the commissures and scattered across the cell on the convex surface, on the concave surface fewer similar-sized pores along the commissures.  Branches short and slightly curved  Branch fascicles with 2 spreading and 2 pendent branches.  Branch leaves ovate, 1.1--1.3 mm, distinctly curved to secund; hyaline cells covered with numerous (more than 30 per cell) tiny pores (ca. 1 \um) on convex surface along the commissures and across the cell surface, sometimes forming several linear rows of free pores, on concave surface with fewer pores round to oval and slightly larger (more than 2 \um) restricted to commissures.  Sexual condition probably dioicous.  Capsule not seen.  Spores not seen.

Commonly in muskeg pond margins, low center polygons, wet meadows, and tundra pool margins, usually occurring in very wet or submerged habitats; Nunavut**c**, N.W.T.**c**; Alaska**n**; Asia.

The ecology of Sphagnum orientale is poorly known, in part due to taxonomic confusion with S. perfoliatum and in part to its very northern distribution.  Like other sect. Subsecunda species, however, it is clearly minerotrophic, probably weakly so.  Associated vascular plants include Carex aquatilis, C. bigelowii, C. misandra, C. rotundata, Eriphorum spissum, Oxycoccus palustris, and Betula glandulosa.  Associated bryophytes include Sphagnum aongstroemii, S. fimbriatum ssp. concinnum, S. jensenii, S. obtusum, S. rubellum, S. talbotianum,S. squarrosum, and Cinclidium subrotundatum.  Sporophytes are rare.  Similar species with which it overlaps in range are S. subsecundum and S. perfoliatum.  It is about the same size as S. subsecundum but typically is much paler in color than the golden to reddish brown of the latter.  Sphagnum perfoliatum is much larger and indeed looks much like some forms of S. lescurii or S.auriculatum, even to having curved, horn-like branches.  Sphagnum perfoliatum is also typically quite richly colored and glossy in appearance.

 

60.  Sphagnum perfoliatum   L. I. Savicz-Lubitskaya, Not. Syst. Sect. Crypt. Inst. Bot. Komar. Acad. Sci. URSS 7: 208.  1951   F

Plants moderate-sized, upright but weak-stemmed; golden-brown to dark brown; capitulum distinct and often with strongly curved branches.  Stems brownish to dark brown; superficial cortex of 1 layer of enlarged, thin-walled cells.  Stem leaves triangular-lingulate to lingulate; 0.8--1.2 mm; apex rounded and sometimes erose; hyaline cells non-septate or sometimes septate, usually fibrillose in distal 1/2 of leaf, convex surface with very small pores (ca. 2 \um) along commisures and free, concave surface with fewer commissural pores.  Branches turgid and often strongly curved.  Branch fascicles with 2 spreading and 2 pendent branches.  Branch leaves ovate-lanceolate; 1.4 or more mm; mostly subsecund; hyaline cells on convex surface with numerous small (2 \um or more) pores along the commissures and sometimes free, concave surface with no pores or fewer small pores along the commissures.  Sexual condition not known.  Capsule not seen.  Spores not seen.

For ecology, see discussion of S. orientale; N.W.T.**c**; Alaska**nAI**; Asia.

Sporophytes of Sphagnum perfoliatum are apparently rare.  Additonal comments are with the discussion of 59. S. orientale.

 

61.  Sphagnum platyphyllum   (Lindberg) Warnstorf, Flora 67: 481.  1884

Sphagnum laricinum var. platyphyllum Lindberg, Not. Sällsk. Faun. Fl. Fenn. Förh. 13: 403.  1874; S. contortum var. platyphyllum (Lindberg) Åberg, S. grasslii H. A. Crum; S. subsecundum var. platyphyllum (Braithwaite) Cardot

Plants small to moderate-sized, unbranched or sparsely branched; green, golden-brown to brown, capitulum small with a large and conspicuous terminal bud.  Stems green to brown; superficial cortex of 2--3 layers of enlarged, thin-walled cells.  Stem leaves broadly ovate, 1.2--2.2 mm; straight; apex rounded; hyaline cells non-septate, convex surface with numerous small pores (less than or equal to 1/6 cell diameter) forming a continuous row along the commissures, concave surface aporose or with a few scattered pores along the commissures and cell ends.  Branches short and blunt, sometimes lacking completely and plants simplex.  Branch fascicles of 1--3 branches, 1--2 of these spreading, branches usually not numerous.  Branch leaves broadly ovate, 1.4--2.5(--3) mm; straight; apex rounded; hyaline cells as in stem leaf.  Sexual condition dioicous.  Capsule exserted, with few pseudostomata.  Spores 23--35 μm; papillose on both surfaces, with indistinct Y-mark sculpture on distal surface; proximal laesura 0.5 spore radius or less.

Capsules mature late spring to early summer.  Typically growing in minerotrophic habitats such as shores of lakes, ponds, streams, flarks of string mires, margins of open fens, especially seasonally flooded sites; Greenland **s**; Alta.**n**, B.C.**c**, Man.**n**, N.B., Nfld. and Labr. (Nfld.), Ont.**c**, Que.**c**, Yukon,**s**; Alaska**c**, Ariz., Calif., Colo., Conn., Ind., Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Y., Ohio, Oreg., Vt., Wis., Wyo.; South America; Eurasia.

Sporophytes are uncommon in Sphagnum platyphyllum, which can be quite variable in size and the development of branch fascicles, with some forms even being simplex while other forms may have up to three branches per fascicle.  The species can usually be recognized by the large stem leaves that are spreading and easily visible because of the scarcity of hanging branches.  It should also be noted that in this species and S. contortum the 2--3 layered stem cortex is not an entirely consistent trait, as plants quite typical in all other respects are occasionally found with the cortex only 1-layered, at least in part.

 

62.  Sphagnum pylaesii   Bridel, Bryol. Univ. 1: 749.  1827

Hemitheca pylaiei Bridel; Sphagnum pylaesii var. austinii (Husnot) Warnstorf; S. pylaesii var. prostratum (Bridel) Cardot; S. pylaesii var. ramosum Warnstorf; S. sedoides Bridel; S. sedoides var. austinii Husnot; S. sedoides var. prostratum Bridel

Plants slender and delicate, aquatic or prostrate, with a conspicuous terminal bud; dark greenish to purplish brown in submerged plants to deep salmon-red in prostrate plants, capitulum quite indistinct but with distinct terminal bud.  Stems pale green to brown; superficial cortex of 1--2 layers of thin-walled enlarged cells.  Stem leaves broadly ovate, 1.5--2(2.5) mm; straight; hyaline cells fibrillose and nearly aporose, with single small pores occasionally found in the distal cell ends on the concave surface.  Branches lacking or short and slender.  Branch fascicles none or 1 spreading branch.  Branch leaves when present similar to stem leaves but smaller, 0.8--1.2 mm, hyaline cells fibrillose and mostly aporose, 1--6 irregularly round-shaped membrane gaps in some cells near apex on convex surface.  Sexual condition dioicous.  Capsule usually immersed in perichaetiale leaves, but may be slightly emergent, pseudostomata absent from capsule surface.  Spores 29--41 \um, coarsely papillose on both surfaces, indistinct raised sculpture on distal surface; proximal laesura less than 0.5 spore radius.

Weakly minerotrophic, wet rocks, poor fens; Greenland**s**; Nfld. and Labr. (Nfld.), N.S., Que.**s**; Maine, Mass., N.H., N.J., N.Y. , N.C.; Europe.

Sporophytes rare in Sphagnum pylaesii.  This species is distributed as a pioneer on wet rocks associated with S. tenellum, and S. papillosum, or in poor fens with S. pulchrum, S. majus, and S. papillosum.  See also discussion of 53. S. cyclophyllum.

 

63.  Sphagnum subsecundum   Nees, Deuts. Fl. Crypt. 2(17): species 3.  1819

Sphagnum crispum R. E. Andrus

Plants small, slender, often wiry; green, yellow-brown or golden-brown; capitulum small with terminal bud absent.  Stems light brown to dark brown; superficial cortex of1 layer of enlarged thin-walled cells.  Stem leaves triangular-lingulate, 0.8 mm or less; apex entire or weakly denticulate, hyaline cells sometimes septate, efibrillose and aporose except near apex.  Branches often short and blunt.  Branch fascicles with 2--3 spreading and 2--3 pendent branches  Branch leaves broadly ovate, subsecund, hyaline cells on convex surface with very numerous small pores (18--40 per cell) in a continuous row along the commissures, concave surface usually aporose.  Sexual condition dioicous.  Capsule exserted, with few pseudostomata.  Spores 30--35 \um; finely papillose on both surfaces, distinct bifurcated Y-mark sculpture on distal surface; proximal laesurae more than 0.5 spore radius.

Minerotrophic, near the edges of open, poor fens, less commonly found in open medium fens; Greenland**c**; Alta,**c** B.C.**c**, Man.**c**, N.B., Nfld. and Labr. (Nfld.), N.W.T.**c**, N.S., Ont.**c**, Que.**c**, Yukon,**c**; Alaska**c,AI,PH**, Calif., Colo., Conn., Idaho, Ill., Ind., Maine, Mass., Mich., Minn., Mont., N.H., N.J., N.Y., Ohio, Oreg., Pa., R.I., Vt., Wash., Wis., Wyo.; Eurasia.

Sporophytes are rare in Sphagnum subsecundum.  This species is often associated with S. angustifolium, S. centrale, S. fimbriatum, S. flexuosum, S. palustre, and S. teres.  The most widespread and common of the sect. Subsecunda, this species also exhibits considerable phenotypic plasticity in size.  However, the stem leaves are always quite small in comparison to those of similar species.  See also discussions of S. contortum, S. inundatum and S. subobesum.

 

1h.  Sphagnum   sect.  Polyclada   (C. E. O. Jensen) Horrell, J. Bot. 38: 119.  1900

Sphagnum [unranked] Polyclada Jensen, Festskr. Bot. Foren Kjøbenhavn 82. 1890; S. [unranked]. Pycnoclada (Russow) H. Klinggräff

Plants small to moderate-sized, with distinct capitulum; green, brown or variegated brown and red.  Stems green to red-brown, superficial cortex of 2--4 layers of efibrillose, non-ornamented, enlarged, short-rectangular cells.  Stem leaves smaller than branch leaves, triangular-lingulate, with rounded apex, border entire; hyaline cells efibrillose, non-ornamented, rhomboid, septate; resorbed on convex surface; concave surface intact except near apex.  Branches dimorphic, spreading branches stiff; pendent branches slender and delicate.  Branch fascicles with 3(--8) spreading and 3(--8) pendent branches.  Branch stems with distinct solitary retort cells, necks not or slightly rostrate.  Branch leaves ovate-lanceolate, apex involute, border entire; hyaline cells fibrillose and non-ornamented, convex surface with 4--6 small ringed ovate pores (approximately 1/4 the diameter of the cell), concave surface with 0--4 unringed pores per cell; chlorophyllous cells elliptic to truncate-elliptic in transverse section, qually exposed on both surfaces.  Sexual condition monoicous or dioicous.  Capsule with few pseudostomata.  Spores 15--24 \um; finely papillose on both surfaces; proximal laesura less than 0.5 the length of the spore.

Species 1 : North America, Eurasia. 

64.  Sphagnum wulfianum   Girgensohn, Arch. Nat. Dorpat II, 2: 173.  1860

Branch leaves with chlorophyllous cells often with faint papillae on interior walls.

Coniferous forests, and occasionally in Alnus or Salix karrs; Greenland**c**; Alta.**c**, B.C.**s**, Man.**s**, N.B., Nfld. and Labr. (Nfld.), N.S., Ont.**s**, Que.**s**; Conn., Ill., Ind., Maine, Mass., Mich., Minn., N.H., N.Y., Ohio, Pa., R.I., Vt., Wis.; Eurasia.

The sporophytes of Sphagnum wulfianum are moderately common.  This is the most dry-growing species in North America, typically growing in association with Sphagnum centrale, S. girgensohnii, S. russowii, and S. squarrosum.  It is easily recognized as the only species that regularly has more than six branches per fascicle.  The Lycopodium clavatum-like growth habit and conifer swamp habitat along with the strongly 5-ranked branch leaves make it even easier to recognize in the field.

 

1i.  Sphagnum   sect.  Acutifolia   Wilson, Bryol. Brit. 20.  1855

Sphagnum sect. Acisphagnum A. L. Andrews; S. sect. Acuta Lesquereux & James; S. sect. Fimbriata Szafran; S. sect. Litophloea Russow; S. sect. Longifolia Szafran; S. sect. Mollia Schimper; S. sect. Pyncnosphagnum J. K. A. Müller; S. sect. Truncata Husnot

Plants small to moderate-sized, rarely robust, with distinct capitulum; green, brown, pink, red.  Stems green, red or brown, superficial cortex of 2--4 layers of efibrillose, non-ornamented, inflated, thin-walled cells, mostly aporose, but may be porose in some species.  Stem leaves similar in size to branch leaves; varying from triangular to lingulate-spatulate; apex varying from acute and entire to very broad and lacerate; border entire or, in one case, fimbriate; hyaline cells rhomboid to S-shaped, non-ornamented, efibrillose or fibrillose, aporose or in hemiisophyllous forms porose, 0--2 septate, mostly resorbed on interior surface and mostly entire on exterior surface.  Branches dimorphic, spreading branches usually longer and thicker than pendent branches.  Branch fascicles with 2(--3) spreading and 1--2 pendent branches.  Branch stems green, surrounded by 1 layer of efibrillose, non-ornamented, inflated, thin-walled hyaline cells, some solitary or in groups of uniporose retort cells, with more or less conspicuous necks.  Branch leaves ovate to ovate-lanceolate, margins entire or, in one case, toothed, involute near smooth apex; hyaline cells efibrillose, non-ornamented, with round to elliptic pores along commissures on convex surface, fewer, larger and round mostly free pores on concave surface; chlorophyllous cells triangular to trapezoidal in transverse section, more broadly exposed on concave surface, end walls not thickened.  Sexual condition usually dioicous, occasionally monoicous.  Capsule equal to or less than 2 mm, with few to many pseudostomata.  Spores typically less than 30 \um, coarsely to finely papillose on both surfaces, may have raised surface sculpture on distal surface; proximal laesura typically less than or equal to 0.5 spore radius.

Species 60 (25 in the flora):   worldwide in distribution excepting Antarctica.

 

1.   Branch leaves with denticulate margin along a resorption furrow.............. 77.   Sphagnum molle

1.   Branch leaf margins plain and bordered without a resorption furrow.

2.   Stem leaves with broad lacerate to fimbriate apex.

3.   Stem leaves with broad, lacerate apex equal to or less than one half the width of the leaf.

4.   Plants red-pigmented.

5.   Branch leaves ovate and deeply concave, stem cortex aporose.............. 65.   Sphagnum andersonianum (in part)

5.   Branch leaves ovate-lanceolate and only slightly concave, stem cortex usually porose 81.   Sphagnum russowii (in part)

4.   Plants brown-pigmented, branch leaves ovate-lanceolate and relatively shallow or moderately concave.

6.   Branch leaves greater than 1.4 mm 67.   Sphagnum arcticum (in part)

6.   Branch leaves less than 1.4 mm 74.   Sphagnum fuscum (in part)

3.   Stem leaves with broad lacerate apex greater or equal to one half the width of the leaf.

7.   Stem leaves spatulate, fimbriate to lacerate across broad apex and along the margins for one-half or more the length; plants slender with conspicuous terminal bud and frequently with numerous sporophytes..... 72.   Sphagnum fimbriatum (in part)

7.   Stem leaves lingulate, fimbriate across the apex; plants small to moderate-sized and rigid, terminal bud if present not conspicuous, sporophytes may or may not be present

8.   Branch fascicles of three spreading and one to two pendent branches; plants green to variegated green and red or red-brown, sporophytes usually present 80.   Sphagnum rubiginosum

8.   Branch fascicles of two spreading and one to two pendent branches; plants green or variegated green and brown or golden brown, sporophytes usually not present.

9.   Surface cells of the stem predominately aporose, but some cells with one elliptical pore at distal cell end; branch leaves longer than 1.4 mm; stem leaves usually longer than 1.2 mm; plants typically brown to dark brown...................... 67.   Sphagnum arcticum(in part)

9.   Surface cells of the stem usually porose with a single elliptical pore in distal portion of cell, but usually free from the cell end wall; branch leaves shorter than 1.4 mm; most stem leaves shorter than 1.2 mm; plants green to brown.

10. Stem leaf hyaline cells frequently septate, strongly so along margins in upper half............. 72.   Sphagnum fimbriatum (in part)

10. Stem leaves only occasionally septate................. 75.   Sphagnum girgensohnii

2.   Stem leaves with acute, slightly toothed, notched, erose, or rounded apex.

11. Plants brown colored; stem brown in green forms.

12. Plants lacking conspicuous metallic sheen when dry.

13. Stem leaves lingulate; branch leaves equal to or less than 1.3 mm; plants small............... 74.   Sphagnum fuscum (in part)

13. Stem leaves lingulate- triangular, broadly ovate-triangular to sublingulate; branch leaves greater than 1.3 mm, plants moderate in size.

14. Stem leaves broadly oblong-ovate to sublingulate, 1.2--1.8 mm, apex broadly acute to narrowly truncate and toothed; branch leaves loosely arranged and spreading, abruptly involute-acuminate in distal third of leaf from ovate to elliptic base, 1.3--2 mm; retort cells with very short or no noticeable neck; one known locality, in B.C.............. 76.   Sphagnum junghuhnianum

14. Stem leaves lingulate-triangular, 1.5--2 mm, apex right angled to apiculate, retort cells with conspicuous neck; northeastern North American coastal regions south to Delaware........................ 73.   Sphagnum flavicomans

12. Plants with metallic sheen when dry.

15. Branch leaves 5-ranked; stem leaves with rounded apices frequently fimbriate, plants very dark brown.

16. Plants with purplish tinge; stem leaves lingulate, hyaline cells in middle of leaf 0--1 septate........ 69.   Sphagnum beothuk

16. Plants with deep red tinge; stem leaves triangular-lingulate, hyaline cells in middle of leaf 1--2 septate
......................................... 70.   Sphagnum bergianum

15. Stem leaves unranked, with hyaline cells rarely more than once septate and apices rarely fimbriate.

17. Stem leaves lingulate-triangular to lingulate, 1--1.5 mm, apex broadly rounded to obtusely angled, and sometimes apiculate, border strongly broadened at base; branch leaves 1.2--1.7 mm, ovate-lanceolate and short-pointed; plants yellowish brown to dark brown......... 83.   Sphagnum subfulvum

17. Stem leaves oblong-triangular, 1.3--1.7 mm, apex broadly acute and usually narrowed to a concave cuspidate point, border slightly broadened at based; branch leaves 1.5--2 mm, narrow-lanceolate, apex recurved when dry; plants yellow- brown and tinged with pink to purplish red.. 84.   Sphagnum subnitens (in part)