Sphagnum papillosum |
Sphagnum steerei |
|
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fat peat-moss, papillose sphagnum |
steere's sphagnum |
|
Habit | Plants moderate-sized to fairly robust; strong-stemmed and generally compact, capitulum usually not much enlarged; greenish brown to deep golden brown; forming compact carpets in floating mats and depressions as well as dense stands on hummock sides and low hummocks. | 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 to 1.3 × 0.7 mm; rarely hemiisophyllous; hyaline cells non-ornamented, mostly septate. |
leaves to 1.2 × 0.8 mm; rarely hemiisophyllous; hyaline cells mostly nonseptate, comb-lamellae usually absent, but sometimes weak. |
Branches | generally short and blunt, leaves spreading. |
short and blunt-tipped, leaves spreading. |
Branch leaves | broadly ovate, 1.7 × 1 mm; hyaline cells on convex surface with round to elliptic pores along the commissures, hyaline cell walls covered with papillae where overlying chlorophyllous cells; chlorophyllous cells trapezoidal to truncate-elliptic in transverse section, equally exposed on both surfaces or less exposed on convex surface, end walls thickened. |
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 | dioicous. |
dioicous. |
Capsule | with numerous pseudostomata. |
unknown. |
Spores | 26–36 µm; more roughly papillose on distal surface than proximal surface, distinct raised, bifurcated-Y mark sculpture on distal surface; proximal laesura 0.5 spore radius or more. |
unknown. |
Branch | fascicles with 2 spreading and 2–3 pendent branches.; branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the interior end walls, mostly with 1 pore per cell on superficial cell wall. |
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 papillosum |
Sphagnum steerei |
|
Phenology | Capsules mature mid to late summer. | |
Habitat | Very common in very poor to poor fen mire habitats where it is often a major peat former, but scarce to absent in truly ombrotrophic peatlands sites | Commonly in firm-bottomed poor to medium fen vegetation, subarctic to arctic regions |
Elevation | low to moderate elevations | low to moderate elevations |
Distribution |
AK; CA; CT; DE; IL; IN; MD; ME; MI; MN; NC; NH; NJ; NY; OH; OR; PA; SC; VT; WA; WI; WV; BC; NB; NF; NS; ON; PE; QC; YT; Eurasia
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AK; MB; NT; NU; QC; YT; e Asia |
Discussion | Sphagnum papillosum is often easily field-identifiable by its rich golden brown to dark brown color and short, blunt branches. Nearly all specimens have the papillae on the branch leaf chorophyll cells but a few smooth forms have been found. Such forms will have stem leaves with divided hyaline cells whereas in the confusable species S. palustre and S. centrale such cells are rare or absent. (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. 53. | FNA vol. 27, p. 54. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | S. cymbifolium var. papillosum, S. papillosum var. laeve, S. papillosum var. sublaeve, S. waghornei | S. imbricatum var. arcticum |
Name authority | Lindberg: Acta Soc. Sci. Fenn. 10: 280. (1872) | R. E. Andrus: Bryologist 90: 218. (1987) |
Web links |