Authors: Richard E. Andrus

Plants moderate-sized to robust, ± weak-stemmed and compact, capitulum conspicuously large and flat-topped; pinkish brown to red-brown; compact low hummocks and hummock sides. Stems brown, superficial cortical layer with spiral reinforcing fibrils lacking or faint, usually 2 or more pores per cell, comb-fibrils lacking on interior wall. Stem leaves to 1.7 ´ 1.2 mm; rarely hemiisophyllous; hyaline cells nonseptate to occasionally septate, comb-lamellae absent. Branches long and tapering. Branch fascicles with 2 spreading and 2 pendent branches. Branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the interior end walls, often with large round pores on the superficial wall. Branch leaves broadly ovate, to 3 ´ 2.3 mm; hyaline cells on proximal half of convex surface with elliptical pores along the commissures, often with ridges running parallel to long leaf axis on hyaline cell surface overlying chlorophyllous cells; chlorophyllous cells elliptical and just enclosed on both surfaces in transverse section; end walls not thickened. Sexual condition dioicous. Capsules not seen. Spores unknown.

Poor to medium fens and mineral edges of ombrotrophic mires; B.C.; Alaska, Wash.

Sphagnum alaskense most resembles S. magellanicum and S. centrale in its chorophyll cell cross-section. The cross-section characteristic is most similar to that of S . centrale S$ but S. alaskense lacks thickened walls. Sphagnum alaskense also does not apparently have any range overlap with S. centrale, with the latter species being more of a boreal forest species. Sphagnum alaskense occurs in more open and less mineral rich sites near the coast. Sphagnum magellanicum has more well-enclosed chlorophyll cells and usually has some purplish coloration color, whereas S. alaskense often has a quite distinctive pinkish brown color which, along with its often large flattened capitula, can give it a distinctive look in the field.