Plants moderate-sized to large, usually quite compact; reddish brown and often yellow flecked with red-brown; in dense stands forming large and tall hummocks. Stems brown, superficial cortical cells with spiral reinforcing fibrils clearly visible, usually 2 or more pores per cell , comb-fibrils lacking on interior wall. Stem leaves 1.2-1.6 × 1 mm; rarely hemiisophyllous; hyaline cells nonseptate or more typically mostly septate, comb-lamellae present on interior wall. Branches clavate, tapering to short point, tightly imbricate at proximal end to somewhat spreading at distal end in less compact forms. Branch fascicles with 2 spreading and 1 pendent branch. Branch stems with cortical cell comb-lamellae visible on interior wall, conspicuous funnel-like projection on interior end walls extending to next cell less than one half its length, pores in superficial wall restricted to leaf bases. Branch leaves ovate-elliptical to elliptical, 1.5-2.1 × 0.8-1.4 mm; hyaline cells on convex surface with numerous moderate-sized round pores along the commissures, comb-lamellae present throughout most of leaf; chlorophyllous cells broadly triangular in transverse section and well-enclosed on the convex surface, end wall not thickened. Sexual condition dioicous. Capsule with scattered pseudostomata. Spores 23-28 µm; coarsely granulate on both surfaces; proximal laesura more than 0.50 spore radius.
Sphagnum cymbifolium subsp. austinii (Sullivant) J. Cardot; S. cymbifolium var. austinii (Sullivant) Warnstorf; S. imbricatum subsp. austinii (Sullivant) Flatberg