Bryum pseudotriquetrum (Hedw.) P.Gaertn., B.Mey. & Scherb.
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Authority
Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part One: Sphagnales to Bryales. Mem. New York Bot. Gard. 69 (1): 1-452.
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Family
Bryaceae
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Scientific Name
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Description
Species Description - Plants medium-sized to large or rarely quite robust, not or shghtiy lustrous, occasionally red-tinted, usually densely tufted. Stems slender to stout, simple or forked by subfloral innovations. Leaves crowded near the tip of fruiting stems or evenly spaced on more elongate, sterile stems, ± wrinkled or twisted and appressed to the stem when dry, erect-spreading when moist, nearly flat to strongly concave, oblong-ovate or broadly oblong-acuminate, narrow and decurrent at base, distinctly bordered by longer, narrower, thicker-walled cells in 2-3 rows; margins serrulate or crenulate only near the apex, usually revolute; costa usually very strong, usually short- to rather long-excurrent; cells short- to relatively long-hexagonal, usually rather thick-walled, rectangular at base. Dioicous or synoicous (in the latter case with leaves tending to be longer and longer-acuminate, with costa longer-excurrent and cells narrower) Setae usually strong, 2.5-4 cm long, rarely more than 5 cm; capsules pendulous to nutant, oblong- or clavate-pyriform, with a short to fairly long, slender neck; operculum relatively large, nearly hemispheric, apiculate; endostome segments widely perforate and cilia appendiculate. Spores 13-15 or occasionally 17-20 µm, roughened.
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Discussion
Fig. 359
B. pseudotriquetrum(}iedv/.) Gaertn., Meyer & Scherb., Okon. Techn. Fl.Wetterau 3(2): 102.1802.
Mnium pseudotriquetrum Hedw., Sp. Muse. 190. 1801.
M. bimum Schreb., Bot. Zeitung (Regensb.) 1: 79. 1802.
Bryum bimum (Schreb.) Turn., Muse. Hib. 127. 1804.
B. samuelssoniiTher., Rev. Bryol. Lichenol. 14: 17. 1944.
The species is extremely variable in size, degree of branching, revolution of margins, differentiation of border, excurrency of costa, and size, shape, and inclination of capsules. The serrulation or crenulation expressed only near the leaf apex appears to be of constant occurrence. In spite of its variability. Bryum pseudotriquetrum can usually be recognized in a sterile state by well-spaced, decurrent leaves and red stems. The leaves of fertile plants are more crowded at the apex of stems and usually only short-pointed owing to slight excurrency of the costa. The upper cells are rather short and fairly thick-walled, with those at the margins longer and narrower in 2-3 rows.
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Distribution
On wet soil in semi-shaded to open sites; Baja California and Oaxaca.—Mexico; widespread throughout the Northern and Southern Hemispheres, absent in tropical and subtropical lowlands