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Sphagnum girgensohnii

(Girgensohn's Sphagnum)

Common Names

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Common Names in English:

Girgensohn's Sphagnum

Description

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Genus Sphagnum

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 285: worldwide except Antarctica, primarily in boreal regions but also in cool, moist montane and oceanic habitats such as nutrient-poor and acidic wetlands and mires .

The concept of species in Sphagnum is controversial. We have followed 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 concepts for species in the Northern Hemisphere. Description of the spores above is from Cao T. and D. H. Vitt (1986) ; for additional discussion of the protonema see C. B . 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 as well as cross sections of branch leaves and stems may need examination.[1]

Physical Description

Species Sphagnum girgensohnii

Plants moderate-sized to robust , open, very stiff and slender, less frequently compact , capitulum large, flat, and stellate ; typically deep green in shaded sites to yellowish brown in more open sites; without metallic lustre when dry. Stems pale green to yellow-brown; superficial cortical cells with a single large round pore in distal portion of cell usually free from cell wall . Stem leaves lingulate , broadly lingulate to lingulate-spatulate; 0.8-1.3 mm, apex broad, truncate and lacerate , border broad at base (more than 0.25 of base) ; hyaline cells rhomboid , efibrillose, and rarely septate . Branches typically long and tapering, not 5-ranked. Branch fascicles with 2 spreading and 1-2 pendent branches. Branch stem with solitary retort cells or in groups of 2-3, necks moderately distinct . Branch leaves ovate to ovate-lanceolate, 1-1.4(-1.8) mm, concave , straight, apex strongly involute , margins entire ; hyaline cells on convex surface with numerous elliptic pores along the commissures , grading from small pores near the apex to large pores near the base, concave surface with large round pores along the margins and base. Sexual condition dioicous. Spores 21-27 µm, moderately to coarsely papillose on both surfaces; proximal laesura less than 0.5 spore radius. Capsules mature late summer. [source]

Sporophytes are uncommon in Sphagnum girgensohnii. This species is most frequently associated with S. russowii, but also found growing with S. centrale, S. fallax, S. fimbriatum, S. warnstorfii, and S. magellanicum when growing in shaded sites of mires . It is very similar to S. rubiginosum, but S. girgensohnii lacks any reddish pigments, has only 2 spreading branches per fascicle, infrequently produces sporophytes, and differs in spore morphology. Throughout much of its range , S. girgensohnii is readily recognized by its green color and its large, slender, strongly stellate capitulum. In the more northern portion of its range, it frequently forms compact stands with a golden brown color and then the stem leaf must often be examined for accurate identification. In Alaska it overlaps morphogically with S. fimbriatum subsp. concinnum, which can look very similar but will have a more spatulate stem leaf that is lacerate completely across the broad flat apex and slightly down the sides. Sphagnum girgensohnii, on the other hand, has stem leaves only lacerate for about 3/4 of the apex width and less conspicuously broadened at the apex. [source]

Habit: Nonvascular

Habitat

Shade tolerant , forming carpets on moist forest floors, along small streams , up through subalpine zone; low to high elevations (Ref. 103584).

Taxonomy

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Unambiguous Synonyms

  1. Sphagnum mehneri Warnstorf

Notes

Name Status: Accepted Name . Latest taxonomic scrutiny: 19-Jul-2004

Similar Species

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Members of the genus Sphagnum

There are approximately 637 species in this genus. Here are just 100 of them:

S. aciphyllum · S. acutifolia · S. acutifolioides · S. acutifolium · S. acutifolium meridense · S. acutifolium pallescens · S. acutifolium purpureum · S. acutifolium quinquefarium · S. acutifolium rubrum · S. acutifolium versicolor · S. acutirameum · S. acutum · S. aequalipunctatum · S. aequifolium · S. aequiporosum · S. affine (Sphagnum) · S. africanum · S. alabamae · S. alaskense · S. albescens · S. alegrense · S. algentryi · S. allionii · S. alpinum · S. amazonense · S. amazonicum · S. ambiguum · S. amblyphyllum · S. americanum · S. amoenoides · S. amoenum · S. andersonianum (Anderson's Sphagnum) · S. andinum · S. angermanicum (Angerman's Sphagnum) · S. angustifolium (Sphagnum) · S. annulatum (Sphagnum) · S. antarcticum · S. antarense · S. antillarum · S. antioquiense · S. aongstroemii (Aongstroem's Sphagnum) · S. apiculatum · S. apollinairei · S. aquatile · S. arbogastii · S. arboreum · S. arcticum (Arctic Sphagnum) · S. atroligneum · S. aureum · S. auriculatum · S. austinii (Austin's Sphagnum) · S. australe · S. austro-americanum · S. austro-molle · S. azuayense · S. bahiense · S. balslevii · S. balticum (Baltic Sphagnum) · S. barclayae · S. bartlettianum (Bartlett's Sphagnum) · S. batumense · S. bavaricum · S. beccarii · S. beyrichianum · S. biforme · S. billbuckii · S. bocainense · S. bolanderi · S. boliviae · S. boomii · S. bordasii · S. borneoense · S. bourbonense · S. boyacanum · S. brachybolax · S. brachycaulon · S. brachycladum · S. brasiliense · S. breedlovei · S. brevicaule · S. brevifolium · S. brevirameum · S. buckianum · S. caldense · S. calymmatophyllum · S. campicola · S. capense · S. capillaceum · S. capillaceum tenellum · S. capillifolioides · S. capillifolium (Sphagnum) · S. capillifolium rubellum · S. capillifolium var. tenellum · S. carlottae · S. carneum · S. carolinianum (Carolina Sphagnum) · S. caroliniarum · S. centrale (Sphagnum) · S. ceylonicum · S. chevalieri

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal February 27, 2008:

Identifiers

Footnotes

  1. "Sphagnum". in Flora of North America Vol. 27 Page 3, 4, 6, 9, 10, 11, 12, 15, 16, 19, 20, 21, 22, 23, 26, 27, 28, 29, 30, 32, 33,. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 2009-04-24