Sphagnum henryense |
Sphagnum inexspectatum |
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Henry's sphagnum |
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Habit | 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. | Plants moderate-sized, normally erect; yellowish to reddish brown, greenish in shaded forms; capitulum moderately distinct and rounded. |
Stem(s) | leaves to 1.9 × 1 mm; rarely hemiisophyllous; hyaline cells non-ornamented, nonseptate or septate. |
leaves triangular-lingulate to ovate-lingulate, 0.8–0.9 mm, apex rounded, straight; hyaline cells mostly non-septate, fibrillose in distal 1/3–2/3 of leaf, a few ringed pores at corners of cells and along commissures on convex surface, ringed pores along the commissures on the concave surface in greater numbers than on convex surface. |
Branches | ± tapering to a point, leaves spreading to moderately imbricate. |
short, not turgid. |
Branch leaves | 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. |
broad-ovate to ovate-lanceolate, 0.9–2.1 mm, straight; hyaline cells with numerous ringed pores (10–20) along the commissures on the convex surface, a few pseudopores and ringed pores (less than 8 per cell) occur on the cell angles on the concave surface. |
Sexual condition | dioicous. |
dioicous. |
Capsule | with numerous pseudostomata. |
exserted, with few pseudostomata. |
Spores | 24–29 µm; surface finely papillose to nearly smooth. |
36–39 µm; coarsely papillose on both surfaces; proximal laesura less than or equal to 0.5 spore radius. |
Branch | 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. |
fascicles with 2–3 spreading and 1–2 pendent branches. |
Sphagnum henryense |
Sphagnum inexspectatum |
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Habitat | Poor to medium fens, common in wooded fens and pond margins | Ecology unclear, but growing in carpets in depressions, blanket mires |
Elevation | low to moderate elevations | low to moderate elevations |
Distribution |
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 |
AK; BC; Asia |
Discussion | 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.) |
Sphagnum inexpectatum is frequently collected with S. tenellum, S. pacificum, S. andersonianum, and S. rubellum in weakly minerotrophic blanket mires. It is similar in size to S. subsecundum, with which its range completely overlaps. The latter species has many of the branch leaves subsecund while those of S. inexspectatum are straight. The stem leaves of S. inexspectatum are also conspicuously larger than those of S. subsecundum. Microscopically Sphagnum inexspectatum has a stem cortex that has enlarged thin-walled cells that form 1–2 layers, whereas S. subsecundum has only one. The stem leaves of S. inexspectatum also have numerous commissural pores in the hyaline cells in the distal half of the concave surface, whereas S. subsecundum has only a few if any in this region and these are more free than commissural. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 27, p. 51. | FNA vol. 27, p. 80. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | S. henryense var. bartlettii | S. subsecundum var. andrusii, S. subsecundum var. junsaiense |
Name authority | Warnstorf: Hedwigia 39: 107. (1900) | Flatberg: Lindbergia 30: 59. (2005) |
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