Authors: Richard E. Andrus

Plants pale yellow-brown, grey-green, to pale brown; not shiny when dry. Stems green to brownish; superficial cortex of 1 sometimes irregularly 2 layers of inflated, thin-walled cells. Stem 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_m along the commissures and scattered across the cell on the convex surface, on the concave surface fewer similar-sized pores along the commissures. Branches short and slightly curved . Branch fascicles with 2 spreading and 2 pendent branches. Branch leaves 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. Sexual condition probably dioicous. Capsules not seen. Spores not seen.

Commonly found in muskeg pond margins, low center polygons, wet meadows, and tundra pool margins, usually occurring in very wet or submerged habitats; N.W.T.; Alaska; Asia.

The ecology is poorly known, in part due to taxonomic confusion with S. perfoliatum and in part to its very northern distribution. Like other sect. Subsecunda species, however, it is clearly minerotrophic, probably weakly so. Associated vascular plants include Carex aquatilis, C. bigelowii, C. misandra, C. rotundata, Eriphorum spissum, Oxycoccus palustris, and Betula glandulosa. Associated bryophytes include Sphagnum aongstroemii, S. fimbriatum, S. jensenii, S. obtusum, S. rubellum, S. teres, and Cinclidium subrotundatum. Sporophytes are rare. Similar species with which it overlaps in range are S. subsecundum and S. perfoliatum. It is about the same size as S. subsecundum$ but typically is much paler in color than the golden to reddish brown of the latter. 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.