Sphagnum sect. Sphagnum
leaves typically as large as or larger than branch leaves, lingulate to ovate-lingulate with broad rounded apex, border fringed;
hyaline cells rhomboid, efibrillose or fibrillose, sometimes ornamented, aporose, 0–2-septate, and often resorbed on exterior surface.
dimorphic, spreading branches tumid, pendent branches usually shorter and more slender.
ovate to broadly ovate, apex cucullate and roughened on convex surface;
margin toothed;
hyaline cells fibrillose;
convex surface pores round to elliptic, usually with 1 at each corner of three adjacent hyaline cells; chlorophyllous cells lenticular to triangular, sometimes with wall ornamentation visible in transverse section; chlorophyllous cells enclosed, equally exposed, or more broadly exposed on concave surface, end walls thickened or unthickened.
usually dioicous.
2 mm or more.
typically 22–30 µm, distal surface sculpture may be present;
proximal laesura usually more than 0.5 spore radius.
fascicles with 2–3 spreading branches and 1–3 pendent branches.;
branch stems green, surrounded by 1 layer of enlarged thin-walled cells, typically porose and fibrillose, in some species ornamented on interior wall;
retort cells absent.
Sphagnum sect. Sphagnum
Species 54 (12 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Branch leaf chlorophyllous cells in transverse section ± equilateral-triangular, often with conspicuous vertically oriented comb-fibrils on the hyaline cells where overlying chlorophyllous cells | → 2 |
1. Branch leaf chlorophyllous cells in transverse section narrowly triangular, trapezoidal, truncate-elliptic, elliptic or lenticular; comb-fibrils if present horizontally oriented | → 6 |
2. Branch cortical cells with funnel-like projections often extending halfway or more into the next cell; branches strongly clavate and blunt. | S. portoricense |
2. Branch cortical cells with flat end walls or with weak funnel-like projections extending less than halfway into the next cell; branches not clavate or if clavate, with pointed ends | → 3 |
3. Interior layer of stem cortical cells with distinct comb-lamellae; branch leaves with or without comb-lamellae; stem leaves without comb-lamellae. | S. affine |
3. Interior layer of stem cortical cells without comb-lamellae or at least not visible with a light microscope; branch leaves with comb-lamellae; stem leaves with or without comb-lamellae | → 4 |
4. Stem leaf hyaline cells with distinct comb-lamellae; branches clavate and pointed; branches leaves strongly imbricate. | S. austinii |
4. Stem leaf hyaline cells without distinct comb-lamellae; branches not clavate; branch leaves more or less spreading | → 5 |
5. Stem leaves short (ca. 0.8-1.1 mm); branch leaves broad (breadth:length ca. 0.7-0.8), branch leaf comb-lamellae usually distinct only in lower half of leaf; branch cortical comb-lamellae present; plants yellow to golden brown. | S. imbricatum |
5. Stem leaves long (ca. 1.1-1.5 mm.); branch leaves narrow (breadth:length ca. 0.6-0.68), branch leaf comb-lamellae distinct throughout most of leaf; branch cortical cell comb-lamellae usually absent; plants dark brown. | S. steerei |
6. Branch leaf chlorophyllous cells in transverse section short-elliptic, elliptic to lenticular, and enclosed on both surfaces | → 7 |
6. Branch leaf chlorophyllous cells in transverse section narrowly triangular, rectangular to truncate-elliptic, exposed equally on both surfaces or more broadly on the convex surface | → 9 |
7. Branch leaf chlorophyllous cells in transverse section short-elliptic and well enclosed; plants purplish red when pigmented. | S. magellanicum |
7. Branch leaf chlorophyllous cells in transverse section narrowly elliptic and slightly enclosed on both surfaces; plants brown when pigmented | → 8 |
8. Branch leaf chlorphyllous cells in transverse section without thickened ends walls; superficial stem cortical cells with reinforcing fibrils weak or absent; branch leaf hyaline cells where overlying chlorophyll cells often with comb-fibrils | S. alaskense |
8. Branch leaf chlorphyllous cells in transverse section with thickened end walls; superficial stem cortical cells with strong reinforcing fibrils; branch leaf hyaline cells where overlying chlorophyllous cells smooth. | S. centrale |
9. Branch leaf hyaline cells papillose where overlying chlorophyllous cells. | S. papillosum |
9. Branch leaf hyaline cells epapillose where overlying chlorophyllous cells | → 10 |
10. Superficial stem cortical cells with fibrils weak or lacking; chlorophyllous cells rectangular to truncate-elliptic, exposed equally on both surfaces. | S. perichaetiale |
10. Superficial stem cortical cells with strong fibrils; chlorophyllous cells triangular, exposed more broadly on concave surface | → 11 |
11. Branch leaf hyaline cells where overlying chlorophyllous cells often with irregular worm-like ridges, especially at the leaf base; pores on the convex surface numerous, small and round to elliptic. | S. henryense |
11. Branch leaf hyaline cells smooth throughout; pores on the convex surface elliptic to flattened-elliptic, not numerous. | S. palustre |
