Sphagnum macrophyllum Brid., Bryol. Univ. 1: 10. 1826.

Plants robust, normally submerged, deep green to red-brown or blackish when wet, shiny and pale green, silvery white, or brownish when dry; cortical cells in 2 layers, those of the epidermis without pores; wood cylinder very hard, yellow-green to brownish. Stem leaves small (about 1 mm long), more or less concave, broadly triangular, rounded at the apex, very indistinctly bordered; hyaline cells rhomboidal, not or rarely divided, without fibrils, on the outer surface with 1 central (sometimes 2–5) large, round to oblong pores usually in a row. Branches short, wide-spreading to somewhat deflexed, not much differentiated as to spreading or pendent types; cortical cells in 1–3 layers, more or less uniform (occasional cells porose but not at all retortlike). Branch leaves crowded, bristly spreading, firm and tubulose when dry, long-elliptic or ligulate to narrowly ovate-oblong, rounded at the narrow tip, with inrolled margins bordered by 2–3 rows of linear cells; hyaline cells nearly plane on both surfaces, very long (15–30:1), linear-sinuose, thick-walled, without fibrils, on the outer surface with (3–)8–14–21) large, rounded-oblong, non-ringed pores in a single median row, on the inner surface without pores; green cells very broadly exposed on both surfaces.