Sphagnum platyphyllum (Lindb.) Sull. ex Warnst., Sphagnol. Eur. 187. 1884.
S. laricinum var. platyphyllum Lindb., Not. Sällsk. Fauna Fl. Fenn. Förh. 13: 403. 1874.
Plants stout, in loose, limp, yellowish to green patches; capitulum not much differentiated but the terminal bud large (especially noticeable when wet); cortical cells in 2–3 layers, mostly porose at the upper ends; wood cylinder dark brown. Stem leaves spreading, concave, broadly oblong-elliptic and rounded-obtuse, 1.5–2(3) mm long, much like branch leaves in size, shape, and structure; hyaline cells fibrillose nearly throughout, rarely divided, on the outer surface with few to many small pores, restricted to ends and corners or in interrupted commissural rows, on the inner surface with pores few, small, at ends and corners. Branches straight, tumid, 1–3 per fascicle, not differentiated into spreading and pendent types and not concealing the stem. Branch leaves erect and imbricate, deeply concave, 1.6–2.5 mm long, broadly oblong-ovate; hyaline cells on the outer surface with few to numerous small, scattered pores or sometimes many in commissural rows; on the inner surface with pores small, few or none.