Dichotomous key to European species of Sphagnum Part 3

Dichotomous key to European species of Sphagnum Part 3
11/9/17

Dichotomous key to European species of Sphagnum Part 3

Taken from the book "Handbook of European Sphagna, ed. 2 - Institute of Terrestrial Ecology"

<< Back to part 2

28

Stem leaves shortly triangular to oval-triangular, ± equilateral: apices obtuse, often slightly concave, rarely pinched to give a mucronate appearance. Pendent and spreading branches strongly dimorphic.

Hyaline cells of pendent branch leaves distinctly wider at apical end. Leaves of spreading branches rarely more than 1.5 mm long.


Sphagnum angustifolium

Stem leaves triangular-lingulate: apices rounded or truncate. Pendent and spreading branches weakly dimorphic. Hyaline cells of pendent branch leaves not distinctly wider at apical end. Leaves of spreading branches rarely less than 1.5 mm long.

29

29

Photosynthetic cells in TS, triangular, not, or rarely, exposed on concave leaf surface. Hyaline cells of lower lateral parts of branch leaves with few to many small, faint pores remote from the commissures (strong staining required). Branch leaves 5-ranked, ± uniform along branch. Plants robust, green or yellowish, in wet mesotrophic to eutrophic mires: often periodically submerged. Scattered to locally frequent, rare in south and extreme north.


Sphagnum obtusum

Photosynthetic cells in TS, trapezoid, exposed on concave leaf surface. Hyaline cells of lower lateral parts of branch leaves without small, faint pores. Branch leaves not consistently 5-ranked: distal leaves of spreading branches often linear. Branch leaf apices with photosynthetic cells as wide as hyaline cells. Plants medium-sized to rather robust, green or ochre, in wet mesotrophic mires. Widespread but less common in the north and confined to montane areas in the south.


Sphagnum flexuosum

30

Plants small. Fascicles often of only 3 branches. Branch leaves small (up to 1.6 mm), often curved and secund. Branch leaf hyaline cells with pores and pseudopores confined to commissures on convex leaf surface. Stem leaves proportionately large, spreading, concave: apices rounded-obtuse. Pendent branch leaves, at least in lower lateral parts, with conspicious: large resorption gaps in the apical angles of hyaline cells. A species of wet oligotrophic mires, often forming extensive 'lawns'. Common in the north and east: more scattered further south and west.


Sphagnum balticum

Plants medium-sized to robust. Fascicles rarely of fewer than 4 branches. Branch leaves rarely less than 1.5 mm long: seldom secund. Branch leaf hyaline cells with few to many pores, remote from

commissures on the convex leaf surface (if lacking such pores, then stem leaves ± triangular and strongly deflexed). Apical resorption gaps, when present, not conspicuously large (ie less than 12.0 μm).


31

31

Stem leaves triangular to oval-triangular, strongly deflexed: apices narrowly obtuse to, apparently, mucronate. Branch leaf hyaline cells in upper mid-part of leaf on convex surface without pores, or with 1-2 pores confined to apical and upper lateral angles. A lowland species, scattered in the south and west.

Sphagnum pulchrum

Stem leaves short-lingulate, concave, ± spreading(sometimes weakly deflexed): apices broadly obtuse. Branch leaf hyaline cells in upper mid-part of leaf on convex surface with few to numerous pores not confined to cell angles. Northern or alpine species.

32

32

Hyaline cells of branch leaves with numerous pores on convex leaf surface; pores absent or few on concave surface. Photosynthetic cells of branch leaves widely exposed on the concave leaf surface. Plants lax: long-leaved.

Sphagnum majus

Hyaline cells of branch leaves with numerous small pores on both leaf surfaces. Photosynthetic cells mostly immersed on concave leaf surface, or only narrowly exposed. Plants lax or firm: not notably long-leaved.

33

33

Branch leaf hyaline cells with numerous, small pores in one or 2 rows, remote from commissures, on both leaf surfaces. A widespread but uncommon boreal to arctic species of oligotrophic mires.

Sphagnum jensenii

Branch leaf hyaline cells with pores usually, along the commissures; seldom numerous or in regular rows on the concave surface. Rare boreal or sub-arctic species.

Sphagnum annulatum

34 - Section Acutifolia

Outer edge of branch leaf border resorbed, forming a furrow (seen as a notch in TS). Stem leaves large: strongly fibrillose and:at least in upper halves, ± identical in structure to branch leaves. Plants medium-sized but low-growing: usually pale, tinged with pink. Locally frequent in the west on shallow peat of wet heaths.

Sphagnum molle

Outer edge of branch leaf border intact. Stem leaves various, without fibrils or weakly fibrillose (strongly fibrillose in S. angermanicum), not identical to branch leaves in upper part.

35

35

Stem leaves lingulate to spatulate (wider above the middle than at insertion), with patches of enlarged hyaline cells above base and also just below apex: hyaline cells never fibrillose: apices rather narrowly to widely fimbriate. Stem cortex with large, distinct pores. Stem bud conical and ± projecting from capitulum. Branch leaves never 5-ranked. Plants pale green to pale ochre, never red or dark brown.


36

Stem leaves various; if wider above the middle, then hyaline cells at least partly fibrillose, branch leaves .5-ranked, or plants red or brown: cells above base not markedly enlarged. Stem cortex without pores, or pores indistinct (sometimes pores more distinct in S. russowii): Stem buds rarely projecting from capitulum. Plants often with at least some red or brown coloration (sometimes confined to internal cylinder of stems and branches).


37

36

Stem leaves expanded above and resorbed-fimbriate around the whole upper part. Stem buds conspicuous, projecting: Plants often tall and thin. Common, especially in the south, in mesotrophic mires, frequently in shade. Fruit common.

Sphagnum fimbriatum

Stem leaves not widely expanded above, fimbriate only across the apices. Stem buds slightly, but inconspicuously, projecting. Plants not usually attenuated-looking. Local in south, common in north in mesotrophic mires and wet woodlands. Fruit rare.

Sphagnum girgensohnii

37

Stem leaves wider at mid-leaf than at insertion: hyaline cells strongly fibrillose. Branch leaves easily flattened: apices broad, not inrolled, strongly dentate. Capitula with projecting stem buds: Plants flaccid, often rather pale: rare in weakly mesotrophic mires.

Sphagnum angermanicum

Stem leaves at mid-leaf as wide as, or narrower than, at insertion: hyaline cells rarely strongly fibrillose. Branch leaves difficult or impossible to flatten because of inrolled margins towards apices (at least in lower leaves of branches). Capitula without projecting stem buds.

38

38

Stems brown. Plants usually brown (at least in part), rarely green, never red. Stem leaves mostly without fibrils. Branch leaves never 5-ranked.

39

Stems green, red or violet. Plants green, red or violet (at least in part): if entirely green, then stem leaves distinctly fibrillose near apex. Branch leaves 5-ranked or not.

40

39

Dried plants irridescent when viewed with a lens. Branch leaf hyaline cells on convex leaf surface mostly with a large (12:0-15.0 p,m) pore in the apical angle. Plants small to medium-sized in somewhat mesotrophic habitats rare to local: boreal.

Sphagnum subfulvum

Dried plants matt, lacking irridescence. Branch leaf hyaline cells on convex surface mostly lacking apical pores: if present, then less than 12.0 pin. Plants small, in oligotrophic mires. Common and widespread in the north: rare to locally frequent towards the south.

Sphagnum fuscum

40

At least some fascicles with 3 spreading branches. Stem, leaves triangular to triangular-lingulate: usually less than 1.4 mm long. Branch leaves conspicuously 5-ranked. Stem cortex with occasional to frequent faint pores (strong staining required). Plants tall, usually variegated pale green and red. Widespread but mainly southern in rather dry, often shaded, habitats: virtually absent from mires.

Sphagnum quinquefarium

Fascicles normally with 2 spreading branches (rarely with an additional branch at a stem bifurcation). Stem leaves lingulate or, if triangular, then over 1.4 mm long and branch leaves not 5-ranked. Stem cortex (except S. russowii) without pores.

41

41

Stem leaves triangular: apices markedly pointed, because of inrolled margins: hyaline cells lacking fibrils. Plants irridescent when dry., often rather loose, with large capitula.

Sphagnum subnitens

Stern leaves lingulate: apices obtuse or ± acute: hyaline cells mostly fibrillose, at least towards the apex (fibrils sometimes weak): Dried plants not irridescent.

42

42

Branch leaves distinctly 5-ranked, especially near the capitulum. Stem leaf hyaline cells without fibrils, or fibrils weak.

43

Branch leaves not distinctly. 5-ranked. Stem leaf hyaline cells strongly fibrillose in upper part.

Sphagnum capillifolium

var. capillifolium

43

Stem leaf lingulate: apex broadly rounded or truncate, often fimbriate. Cells of stem cortex with occasional pores or thinnings. Branch leaf hyaline cells with large, circular pores throughout on concave leaf surface. Plants medium-sized to rather small: widely distributed in oligotrophic mires and paludified woods. Species with northern tendencies.


Sphagnum russowii

Stem leaf lingulate to lingulate-triangular: apex narrowly rounded to subacute, not fimbriate. Outer cells of stem cortex without large pores or thinnings. Branch leaf hyaline cells in mid-leaf on concave leaf surface without pores.

44

44

Branch leaf hyaline cells, in upper half of leaf, with small, circular, thick-ringed pores on the convex leaf surface (pores less than 5.0 μm, including ring). Plants usually deep red, occasionally green with red flecks: in eutrophic habitats. Abundant in the north, but towards the south increasingly confined to montane areas.

Sphagnum warnstorfii

Branch leaf hyaline cells with larger (more than 5.0 μm), apparently half-elliptical pores against the commissures. Plants of mesotrophic and oligotrophic habitats.

Sphagnum capillifolium 44a

44a - Sphagnum capillifolium

Capitula ± hemispherical. Branch leaves not consistently 5-ranked. Plants often compact and dense. Branch leaf hyaline cells with pores 10.0-15.0 μm on convex surface at mid-leaf.

S. capillifolium var. capillifolium

Capitula ± flat. Branch leaves 5-ranked. Plants usually lax. Branch leaf hyaline cells with pores 6.0-12.0 μm on convex surface at mid-leaf.

S. capillifolium var. rubellum

Add Comment

You must login to add a comment. If you do not have an account, you may register for one. Registration is free!