Sphagnum sect. Rigida
in G. L. Rabenhorst et al., Krypt.-Fl. ed. 2, 4(1): 116. 1885,.
Plants low-growing in loose mats to compact cushions, capitulum often indistinct or concealed by upwardly directed branches; pale green, straw-colored, brownish to reddish. Stems with superficial cortex of 1–3 layers of efibrillose, inflated, thin-walled, nonornamented, and aporose cells. Stem-leaves much smaller than branch leaves, triangular-lingulate, border entire and broadened at base; hyaline cells rhomboid, efibrillose, nonornamented, aporose, and usually nonseptate; hyaline cells not resorbed on either surface. Branches strongly dimorphic, spreading branches much stronger than pendent branches. Branch fascicles with 2–3 spreading branches and 2 (–3) pendent branches. Branch stems green, green to brownish, surrounded by 1 layer of efibrillose, nonornamented, inflated, thin-walled, uniporse cells with slight protruding necks. Branch leaves ovate to ovatelanceolate, apex broadly truncate, smooth and toothed; margin denticulate; hyaline cells fibrillose, smooth or papillose, convex surface with ± 5 small to medium-sized free pores, sometimes numerous pseudopores, concave surface with large pores in cell angles; chlorophyllous cells elliptic to ovate-triangular in transverse-section, completely enclosed or exposed on concave surface, end walls unthickened. Sexual condition monoicous or dioicous. Capsule 2 mm or less, with numerous pseudostomata. Spores mean diameter more than 30 µm, raised Y-mark sculpture on distal surface; proximal laesura more than 0.3 spore radius.
Distribution
Worldwide except Antarctica
Discussion
Species 5 (2 in the flora).
Selected References
None.
Lower Taxa
Key
1 | Chlorophyllous cells of branch leaves elliptic in transverse section and completely enclosed on both surfaces, adjacent hyaline cell walls smooth; stem leaves lingulate to oblong-triangular. | Sphagnum compactum |
1 | Chlorophyllous cells of branch leaves elongate-triangular to ovate-triangular, enclosed on the adaxial surface and exposed on the convex surface, adjacent hyaline cell walls minutely papillose; stem leaves bluntly deltoid. | Sphagnum strictum |
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