Sphagnum obtusum |
Sphagnum fimbriatum |
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sphagnum |
fringe bogmoss, fringe peat-moss, sphagnum |
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Habit | 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. | Plants typically small and slender, larger and compact in the Arctic, capitulum small to moderate-sized, often with a conspicuous terminal bud; green, yellowish brown to brown; without metallic lustre when dry. | ||||
Stem(s) | 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. |
leaves spatulate to broad-spatulate, 0.8–1.5(–2) mm, strongly lacerate across the broad apex and often part way down the margins, border scarcely to strongly broadened at base (0.25 width of base or less); hyaline cells rhomboid, efibrillose and often 1–2-septate. |
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Branches | tapering or in more robust forms, frequently blunt, straight to arcuate, leaves slightly to moderately elongated at distal end. |
not 5-ranked, quite terete, long, and slender Branch fascicles with 1– 2 spreading and 1–2 pendent branches. |
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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. |
ovate to ovate-lanceolate; 1.1–1.5(–2) mm, slightly concave, straight; apex involute; margins entire; hyaline cells on convex surface with numerous pores along the commissures grading from small pores near leaf apex to large pores at base, concave surface with large round pores at leaf apex and along margins. |
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Sexual condition | dioicous. |
often monoicous. |
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Spores | 18–27 µm; 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. |
20–27 µm, finely papillose on both surfaces; proximal laesura less than 0.5 spore radius. |
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Branch | fascicles with 2 spreading and 2 pendent branches.; branch stems green, with cortex enlarged with conspicuous retort cells. |
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Sphagnum obtusum |
Sphagnum fimbriatum |
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Habitat | Forming carpets in minerotrophic peatlands | |||||
Elevation | low to moderate elevations | |||||
Distribution |
AK; MN; AB; BC; MB; NF; NT; NU; ON; QC; SK; YT; Greenland; Eurasia |
North America; South America; Eurasia; Pacific Islands (New Zealand)
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Discussion | 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, easily separate S. obtusum microscopically from other species of sect. Cuspidata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Subspecies 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 27, p. 73. | FNA vol. 27, p. 92. | ||||
Parent taxa | ||||||
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Name authority | Warnstorf: Bot. Zeitung (Berlin) 35: 478. (1877) | Wilson & Hooker: in J. D. Hooker, Fl. Antarct., 398. (1847) | ||||
Web links |