Sphagnum balticum |
Sphagnum tenerum |
|
---|---|---|
Baltic peat-moss, Baltic sphagnum |
sphagnum |
|
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 ± robust, weak-stemmed, and compact, capitulum hemispherical, branches in capitulum short and blunt; typically mottled pale yellow-green and purplish red, without metallic sheen when dry. |
Stem(s) | leaves 0.8–1.1 mm, triangular-lingulate to lingulate, concave, spreading, apex broadly obtuse, hyaline cells fibrillose in apical region. |
leaves 1.4–1.8 mm, elongate-triangular, lingulate-triangular, hemiisophyllous forms elongate triangular-ovate, 1.4–1.8 mm, apex usually conspicuously toothed, border narrow at base (less than 0.25 width); hyaline cells narrowly rhombic to S-shaped, can be efibrillose and aporose but more commonly fibrillose and porose, 0–1-septate. |
Branches | slender and tapering, often 5-ranked and decurved, leaves somewhat elongated at distal end. |
turgid and terete, leaves, not 5-ranked. |
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, 1.1–1.7 mm, slightly concave, straight, apex weakly involute and conspicuously toothed; hyaline cells on the convex surface with round to elliptic pores along the commissures, grading from moderate-sized pores near apex to large pores at leaf base, concave surface with large round pores throughout. |
Sexual condition | dioicous. |
uncertain, monoicous or dioicous or possibly both. |
Spores | 25–33 µm; smooth to finely papillose on both surfaces; proximal laesura approximately 0.5 spore radius. |
22–25 µm, finely roughened. |
Branch | fascicles with 2 spreading and mostly 1 pendent branch.; branch stem green, cortex enlarged with conspicuous retort cells. |
fascicles with 2 spreading and 1–2 pendent branches. |
Sphagnum balticum |
Sphagnum tenerum |
|
Habitat | Abundant in hollows and floating mats in raised bogs and poor fens | Damp sand and thin humus especially around pond margins, open savannas, and pine barrens |
Elevation | low to high elevations | low to moderate elevations |
Distribution |
AK; CO; AB; BC; MB; NT; NU; ON; QC; YT; Greenland; Eurasia |
AL; DC; DE; FL; GA; KY; MD; NC; NJ; NY; PA; RI; SC; TN; VA |
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 Spagnum tenerum. The sexual condition is uncertain because of past taxonomic confusion with S. capillifolium (R. E. Andrus 1980). Sphagnum tenerum is usually described (incorrectly) as having hemiisophyllous stem leaves, and many collections of other species of sect. Acutifolia with such leaves have been called S. tenerum. When correctly characterized, S. tenerum is can be confused only with S. capillifolium, with which it has only a very small range overlap. Microscopically, besides the otherwise quite different S. angermanicum, S. tenerum is the only species of sect. Acutifolia with large round free pores in most of the branch leaf hyaline cells on their concave surfaces. See also discussion under 71. S. capillifolium. Sexual condition and spore features were taken from H. A. Crum (1984). The name Sphagnum evansii Warnstorf has also been used for this taxon. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 65. | FNA vol. 27, p. 100. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | S. recurvum subsp. balticum | S. capillaceum var. tenerum, S. capillifolium var. tenerum, S. tenerum var. virginicum |
Name authority | (Russow) C. E. O. Jensen: in Botaniske Forening København, Festskrift, 100. (1890) | Sullivant: in A. Gray, Manual ed. 2, 611. (1856) |
Web links |