Sphagnum steerei |
Sphagnum molle |
|
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steere's sphagnum |
sphagnum |
|
Habit | 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. | Plants moderate-sized, soft and lax when wet, stiff when dry, typically very compact, capitulum flat and usually large; pale whitish, yellowish or purplish, occasionally a deep purple-red; without metallic sheen when dry. |
Stem(s) | leaves to 1.2 × 0.8 mm; rarely hemiisophyllous; hyaline cells mostly nonseptate, comb-lamellae usually absent, but sometimes weak. |
leaves quite variable in shape, elongate-lingulate to ovate, broadest above the middle, 1.9–2.5 mm, slightly concave, straight; apex broad and toothed; hyaline cells narrowly rhomboid, 0–1-septate, distal portion fibrillose, convex surface with membrane pleats, concave surface with 1(2–3) oblong membrane gaps. |
Branches | short and blunt-tipped, leaves spreading. |
rarely 5-ranked. |
Branch leaves | 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. |
ovate, 1.6–2.2 mm, concave, straight; apex stiffly involute and broadly truncate with up to 8 teeth, border denticulate due to cell wall resorption and projecting cell walls; hyaline cells strongly bulging on convex surface and nearly plane on the concave surface, convex surface with narrowly elliptic pores along commissures grading from smaller pores near the apex to large rounded pores at base, concave surface with large round pores in proximal regions of leaf. |
Sexual condition | dioicous. |
monoicous. |
Capsule | unknown. |
|
Spores | unknown. |
27–33 µm, finely papillose on both surfaces with distinct bifurcated Y-mark sculpture on distal surface; proximal laesura less than 0.5 spore radius. |
Branch | 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. |
fascicles with 2 spreading and 1–2 pendent branches. |
Sphagnum steerei |
Sphagnum molle |
|
Phenology | Capsules mature early to mid summer. | |
Habitat | Commonly in firm-bottomed poor to medium fen vegetation, subarctic to arctic regions | Weakly minerotrophic and hygrophytic, poor fens and sand dunes, forming tight cushions among grasses and sedges in savannas, pine barrens, swamps, pond margins, and ditches where periodic dessication is common |
Elevation | low to moderate elevations | low to high elevations |
Distribution |
AK; MB; NT; NU; QC; YT; e Asia |
AL; DE; FL; GA; KY; LA; ME; MS; NC; NJ; NY; SC; TX; VA; LB; Europe |
Discussion | 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.) |
The sporophytes of Sphagnum molle are common. This species is usually easily distinguished from other red species of sect. Acutifolia by its relatively large, straight, loosely spreading and unranked branch leaves. Sphagnum tenerum, the other red species of sect. Acutifolia to which it is most similar, has branch leaves that are quite imbricate. Microscopically, the denticulate-margined branch leaves are unmistakeable. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 54. | FNA vol. 27, p. 95. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | S. imbricatum var. arcticum | S. labradorense, S. tabulare |
Name authority | R. E. Andrus: Bryologist 90: 218. (1987) | Sullivant: Musc. Allegh., 205. (1846) |
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