Plants moderate-sized and fairly strong-stemmed; green, yellow to yellowish brown; capitulum 5­radiate in shade forms to hemispherical in open grown or drier growing forms. Stems pale green to pale brown, sometimes with red branch bases; superficial cortex of 2 layers of enlarged, clearly differentiated and thin-walled cells. Stem leaves triangular to lingulate-triangular, 0.8-1.3 mm; typically appressed; apex acute to apiculate; hyaline cells efibrillose and nonseptate to rarely septate. Branches straight and somewhat tapered, usually 5-ranked; leaves little elongate at the distal branch end. Branch fascicles with 2 spreading and 2-3 pendent branches. Branch stems green but often reddish at proximal end, with cortex enlarged with conspicuous retort cells. Branch leaves ovate to narrowly ovate-lanceolate; (1.1-)1.4-1.8(-3.1) mm; slightly undulate and sharply recurved when dry, somewhat subsecund; margins entire; hyaline cells on convex surface with usually 1 round pore on apical end, on concave surface with wall thinnings in the cell ends and angles; chlorophyllous cells broadly triangular in transverse section and very deeply enclosed on the concave surface. Sexual condition dioicous. Spores 19-25 µm; finely papillose on both surfaces.

Forested and open poor fen habitats, often as a ruderal species in extensive mats; low to moderate elevations; B.C.; Alaska, Oreg., Wash.

Sporophytes in Sphagnum pacificum are uncommon. See discussion under 26. S. brevifolium. Characters of the spores are taken from Flatberg´s description.