Sphagnum tenerum |
Sphagnum steerei |
|
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sphagnum |
steere's sphagnum |
|
Habit | 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. | Plants moderate-sized to large, compact and stiff-stemmed with upswept branches; dark green and brown, dark chesnut brown, brown to blackish brown, often with bluish tinge when dry; forming dense low to moderately tall hummocks. |
Stem(s) | 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. |
leaves to 1.2 × 0.8 mm; rarely hemiisophyllous; hyaline cells mostly nonseptate, comb-lamellae usually absent, but sometimes weak. |
Branches | turgid and terete, leaves, not 5-ranked. |
short and blunt-tipped, leaves spreading. |
Branch leaves | 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. |
ovate to ovate-elliptical, 1.6–2.2 × 1 mm; hyaline cells on proximal half of convex surface with round to elliptic pores along the commissures; comb-lamellae on hyaline cell wall where overlying chlorophyllous cells; chlorophyllous cells broadly triangular in transverse section and well-enclosed on convex surface, end wall not thickened. |
Sexual condition | uncertain, monoicous or dioicous or possibly both. |
dioicous. |
Capsule | unknown. |
|
Spores | 22–25 µm, finely roughened. |
unknown. |
Branch | fascicles with 2 spreading and 1–2 pendent branches. |
fascicles with 2 spreading and 1 pendent branch.; branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the end walls of cortical cells, cortical cell walls usually with large round pores. |
Sphagnum tenerum |
Sphagnum steerei |
|
Habitat | Damp sand and thin humus especially around pond margins, open savannas, and pine barrens | Commonly in firm-bottomed poor to medium fen vegetation, subarctic to arctic regions |
Elevation | low to moderate elevations | low to moderate elevations |
Distribution |
AL; DC; DE; FL; GA; KY; MD; NC; NJ; NY; PA; RI; SC; TN; VA |
AK; MB; NT; NU; QC; YT; e Asia |
Discussion | 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.) |
Sphagnum steerei is usually easily recognized in the field by its dense growth habit and dark brown color. Its ecology is somewhat unclear due to taxonomic confusion with S. imbricatum in the strict sense and S. austinii (R. E. Andrus 1987). The latter is the only species in the imbricatum complex that occurs where S. steerei does. Contrary to the view of H. A. Crum (1997), S. steerei is quite distinct from S. affine and S. austinii. There is no range overlap with either of those species and the macroscopic appearance is also quite different. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 100. | FNA vol. 27, p. 54. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | S. capillaceum var. tenerum, S. capillifolium var. tenerum, S. tenerum var. virginicum | S. imbricatum var. arcticum |
Name authority | Sullivant: in A. Gray, Manual ed. 2, 611. (1856) | R. E. Andrus: Bryologist 90: 218. (1987) |
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