Sphagnum balticum |
Sphagnum obtusum |
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Baltic peat-moss, Baltic sphagnum |
sphagnum |
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Habit | Plants small to moderate-sized, soft and ± weak-stemmed; brownish green, yellow-green, yellowish to golden brown, capitulum typically flat and 5-radiate. | 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(s) | leaves 0.8–1.1 mm, triangular-lingulate to lingulate, concave, spreading, apex broadly obtuse, hyaline cells fibrillose in apical region. |
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 | slender and tapering, often 5-ranked and decurved, leaves somewhat elongated at distal end. |
tapering or in more robust forms, frequently blunt, straight to arcuate, leaves slightly to moderately elongated at distal end. |
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. |
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. |
dioicous. |
Spores | 25–33 µm; smooth to finely papillose on both surfaces; proximal laesura approximately 0.5 spore radius. |
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. |
Branch | fascicles with 2 spreading and mostly 1 pendent branch.; branch stem green, cortex enlarged with conspicuous retort cells. |
fascicles with 2 spreading and 2 pendent branches.; branch stems green, with cortex enlarged with conspicuous retort cells. |
Sphagnum balticum |
Sphagnum obtusum |
|
Habitat | Abundant in hollows and floating mats in raised bogs and poor fens | Forming carpets in minerotrophic peatlands |
Elevation | low to high elevations | low to moderate elevations |
Distribution |
AK; CO; AB; BC; MB; NT; NU; ON; QC; YT; Greenland; Eurasia |
AK; MN; AB; BC; MB; NF; NT; NU; ON; QC; SK; YT; Greenland; Eurasia |
Discussion | Unlike Sphagnum angustifolium and S. annulatum, S. balticum has stem leaves exerted at right angles to the stem. It also has fewer and weaker hanging branches than does 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. In Sphagnum kenaiense there are sometimes spreading stem leaves but this species has 2 hanging branches per fascicle. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 27, p. 65. | FNA vol. 27, p. 73. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | S. recurvum subsp. balticum | |
Name authority | (Russow) C. E. O. Jensen: in Botaniske Forening København, Festskrift, 100. (1890) | Warnstorf: Bot. Zeitung (Berlin) 35: 478. (1877) |
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