Sphagnum centrale |
Sphagnum henryense |
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sphagnum |
Henry's sphagnum |
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Habit | Plants moderate-sized to robust, capitulum compact and well rounded in open-grown forms, lax to somewhat compact; green in shade forms to golden yellow to golden brown in open-grown forms, occasionally with a pinkish tinge; lawns, loose low hummocks to larger, ± firm hummocks. | Plants moderate-sized to robust, capitulum typically flat, ± 5-radiate and with terminal bud slightly visible; green, pale green, to pale pinkish brown tinged with brown to reddish brown; forming carpets or low hummocks. |
Stem(s) | leaves to 1.2–2.2 × 0.8–1 mm; rarely hemiisophyllous; hyaline cells non-ornamented, rarely septate, comb-lamellae absent. |
leaves to 1.9 × 1 mm; rarely hemiisophyllous; hyaline cells non-ornamented, nonseptate or septate. |
Branches | tapering, leaves spreading to somewhat imbricate. |
± tapering to a point, leaves spreading to moderately imbricate. |
Branch leaves | broadly ovate, to 1.7 × 1.5 mm; hyaline cells non-ornamented, convex surface with elliptic to rarely round pores along the commissures; chlorophyllous cells lenticular to narrowly elliptical in transverse section, narrowly exposed on both ends, but more so on concave surface, end walls thickened at both ends. |
ovate, to 2.7 × 1 mm; hyaline cells on convex surface with numerous small round pores along the commissures, cell walls overlying chlorophyll cells often with a network of irregular worm like ridges although they may be lacking; chlorophyllous cells isosceles-triangular to narrowly ovate triangular in transverse section and just enclosed on convex surface,end wall not thickened. |
Sexual condition | dioicous. |
dioicous. |
Capsule | with inconspicuous pseudostomata. |
with numerous pseudostomata. |
Spores | 23–30 µm; surface finely roughened to smooth; laesura on proximal surface more than 0.5 spore radius. |
24–29 µm; surface finely papillose to nearly smooth. |
Branch | fascicles with 2 spreading and 1–2 pendent branches.; branch stems with cortical cells non-ornamented, no or weak funnel-like projections on the interior end walls, often with large round pores on the superficial walls. |
fascicles with 2 spreading and 2 pendent branches.; branch stems with hyaline cells non-ornamented; funnel-like projections absent from interior end walls, large round pores on superficial walls. |
Sphagnum centrale |
Sphagnum henryense |
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Phenology | Capsules uncommon, mature late summer. | |
Habitat | Medium to rich fens, especially prominent in coniferous fens and sedge fens | Poor to medium fens, common in wooded fens and pond margins |
Elevation | low to high elevations | low to moderate elevations |
Distribution |
CT; IA; ID; IL; IN; MA; ME; MI; MN; MT; NH; NJ; NY; OH; PA; VT; WA; WI; AB; BC; NF; NS; NT; ON; PE; QC; SK; Greenland; Eurasia
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AK; AL; AR; CA; CT; DC; DE; FL; GA; IL; IN; LA; MA; MD; ME; MI; MO; MS; NC; NH; NJ; NY; OH; OK; OR; SC; TN; TX; VA; VT; WI; WV; BC; NF; NS; PE; Asia |
Discussion | Sphagnum centrale is most similar to S. alaskense but seems to have no range overlap with that species and is also considerably more minerotrophic. In the field it lacks the often reddish tinge of S. palustre and is larger than S. affine. See also discussion under 2. S. alaskense and 9. S. papillosum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The typical form of Sphagnum henryense is a large plant with a quite flat capitulum with a small terminal bud. Microscopically, typical material has distinct ridges on the branch leaf hyaline cells and relatively small and round pores on the branch leaf hyaline cell convex surface. Sphagnum palustre, which has the same branch leaf chlorophyll cell cross section, typically has smooth hyaline cell walls and hyaline cell pores that are larger and more elliptical in shape. However, Sphagnum species are plastic phenotypically and it is common to find plants that cannot be reliably assigned to either S. henryense or S. palustre. For example, some species of Sphagnum that are relatively easy to distinguish on other characteristics, such as S. papillosum, S. alaskense and S. affine, may occasionally completely lack any hyaline cell ornamentation or display it in reduced form. Since these can be distinguished on other characters, the species are still readily identifiable, but when S. henryense lacks the ornamentation, there is no other solid character to distinguish it from S. palustre. Thus, although we can find material from both North American coasts that has good ornamentation (R. E. Andrus 1980), there is much other material that looks in other respects like S. henryense but lacks the ornamentation. Barring taxonomy beyond microscopic examination, many collections of henryense/palustre will of necessity not be absolutely identifiable. Where their ranges overlap, mixed stands may often be found. We believe that the species are still good, but accurate delimitation of their distinctive ecologies and ranges will be very problematic. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 50. | FNA vol. 27, p. 51. |
Parent taxa | Sphagnaceae > Sphagnum > sect. Sphagnum | Sphagnaceae > Sphagnum > sect. Sphagnum |
Sibling taxa | ||
Synonyms | S. palustre subsp. intermedium, S. subbicolor | S. henryense var. bartlettii |
Name authority | C. E. O. Jensen: Bih. Kongl. Svenska. Vetensk.-Akad. Handl. 21(10): 34. (1896) | Warnstorf: Hedwigia 39: 107. (1900) |
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