Sphagnum atlanticum
Sphagnum orientale
Atlantic sphagnum
oriental sphagnum
leaves triangular, large, less than 1.7 mm, mostly appressed to stem, apex weakly apiculate to narrowly obtuse;
hyaline cells efibrillose and seldom to often septate at base and sides.
leaves triangular-lingulate to lingulate; 0.7–0.8 mm;
apex rounded and often erose, hyaline cells nonseptate or sometimes 1-septate, numerous small round pores more than 2 µm along the commissures and scattered across the cell on the convex surface, on the concave surface fewer similar-sized pores along the commissures.
unranked, long and tapering, leaves greatly elongate at distal end.
short and slightly curved Branch fascicles with 2 spreading and 2 pendent branches.
ovate-lanceolate to lanceolate in aquatic forms, ovate to ovate-lanceolate in emergent forms, greater than 2.5 mm, often falcate-secund, especially in submerged forms, weakly undulate and recurved when dry;
margin entire, hyaline cells on convex surface with 0–1 pores per cell, concave surface with round wall thinnings in the cell apices and angles; chlorophyllous cells narrowly triangular in transverse section and well-enclosed on the concave surface.
ovate, 1.1–1.3 mm, distinctly curved to secund;
hyaline cells covered with numerous (more than 30 per cell) tiny pores (ca. 1 µm) on convex surface along the commissures and across the cell surface, sometimes forming several linear rows of free pores, on concave surface with fewer pores round to oval and slightly larger (more than 2 µm) restricted to commissures.
dioicous.
probably dioicous.
not seen.
not seen.
fascicles with 2 spreading and 2 pendent branches.;
branch stem green, cortex enlarged with conspicuous retort cells.
not seen.
Sphagnum atlanticum
Sphagnum orientale
Sporophytes of Sphagnum atlanticum are rare. The other large North American Atlantic coastal plain species of sect. Cuspidata, S. torreyanum, is typically more yellow, has a more rounded capitulum, and has straight rather than subsecund branch leaves.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The ecology of Sphagnum orientale is poorly known, due in part to taxonomic confusion with S. perfoliatum and in part to its very northern distribution. Like other species of sect. Subsecunda, however, it is clearly minerotrophic, probably weakly so. Associated vascular plants include Carex aquatilis Wahlenberg, C. bigelowii Torrey, C. fuliginosa Schkuhr, C. rotundata Wahlenberg, Eriophorum vaginatum Linnaeus, Vaccinium oxycoccus Linnaeus, and Betula glandulosa Michaux. Associated bryophytes include Sphagnum aongstroemii, S. fimbriatum subsp. concinnum, S. jensenii, S. obtusum, S. rubellum, S. talbotianum, S. squarrosum, and Cinclidium subrotundatum. Sporophytes are rare. Similar species with which it overlaps in range are S. subsecundum, S. perfoliatum and S. inexspectatum. Field separation from S. subsecundum and S. inexspectatum is difficult but the tiny branch leaf pores will separate it microsopically. Sphagnum perfoliatum is much larger and indeed looks much like some forms of S. lescurii or S.auriculatum, even to having curved, horn-like branches. Sphagnum perfoliatum is also typically quite richly colored and glossy in appearance.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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USDA Plants Database
