Sphagnum sect. Squarrosa
leaves ovate, ovate-lingulate to lingulate;
with broad, fringed apex;
little or no border along margins or base;
hyaline cells rhomboid, efibrillose, non-ornamented, aporose, usually nonseptate, with resorption gaps on exterior surface.
strongly dimorphic, pendent branches thinner but about same length as spreading branches.
strongly squarrose or spreading, ovate, ovate-hastate or ovate-lanceolate, margins entire, apex involute and smooth;
hyaline cells fibrillose;
with large, round pores at cell ends and along commissures, sometimes with faint papillae on interior walls; chlorophyllous cells ovate-triangular, elliptical to ovate-elliptical in transverse section, more broadly exposed on convex surface, end walls not thickened.
monoicous or dioicous.
2 mm or more, with scattered pseudomata.
less than 30 µm, both surfaces smooth to finely papillose;
proximal laesura more than 0.5 spore radius.
stems green, with cortex surrounded by 1–2 layers of efibrillose, non-ornamented, enlarged, thin-walled cells, some cells apically porose with inconspicuous necks.
Sphagnum sect. Squarrosa
Species 4 (4 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Branch leaves markedly truncate; chlorophyll cells ovate-triangular in transverse section, with the widest part at or near the convex surface. | S. tundrae |
1. Branch leaves not truncate; chlorophyll cells elliptical to elliptical-ovate with the broadest part typically some distance from the convex surface | → 2 |
2. Branch leaves strongly squarrose (terete in tundra forms), large (1.9-3 mm); hyaline cells of branch leaves with ringed elliptic pores on concave surface and unringed pores on convex surface; stem leaves 1/2-2/3 as long as branch leaves (1.1-1.9 mm) | S. squarrosum |
2. Branch leaves imbricate (squarrose in shade forms), moderate in size (1-1.5 mm); hyaline cells of branch leaves with unringed pores on concave and convex surfaces; stem leaves as long or longer than branch leaves (1-1.7 mm) | → 3 |
3. Branch leaf hyaline cells near leaf base on convex surface mostly aporose and on concave surface with large, faint pores; 1-2 hanging branches. | S. mirum |
3. Branch leaf hyaline cells near leaf base on convex surface with large, round pores and on concave surface mostly aporose; 2-3 hanging branches. | S. teres |
