Sphagnum sect. Insulosa

Isoviita

Ann. Bot. Fenn. 3: 231. 1966,.

Basionym: Truncata Warnstorf ex Horrell J. Bot. 38: 119. 1900,
Treatment appears in FNA Volume 27. Treatment on page 57. Mentioned on page 47.

Plants moderate-sized, with distinct capitulum; pale brownish yellow, yellow-green, loosely tufted. Stems green, superficial cortex of 3–4 layers of efibrillose, inflated, thin-walled, non-ornamented cells, with an occasional pore in the distal end of the outer wall of the superficial cell layer. Stem leaves smaller than branch leaves, oblong to lingulate, moderately lacerate across broad rounded apex, border entire and broad at base; hyaline cells rhomboid, aporose, non-ornamented, usually efibrillose, resorbed on distal portion of leaf with membrane pleats in proximal portion. Branches dimorphic, the spreading branches stronger than the pendent branches. Branch fascicles with 2–3 spreading and 2–3 pendent branches. Branch stems green, surrounded by 1 layer of efibrillose, non-ornamented, inflated, thin-walled cells with inconspicuous necks. Branch leaves broadly ovate, very concave, apex broadly truncate, smooth, and toothed; margin entire; hyaline cells non-ornamented, fibrillose; with elliptic, ringed pores at ends and corners of cells, usually found in 3s at adjoining cell walls, pores more numerous on concave surface (5–8 per cell) than on convex surface (3–5 per cell); chlorophyllous cells in transverse section narrowly truncate-elliptic to lenticular, lacking wall sculptures, with thickened end walls equally exposed on both surfaces. Sexual condition dioicous. Capsule not seen. Spores not seen.

Distribution

nw North America, Eurasia.

Discussion

Species 1.

Selected References

None.