Glossadelphus
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Authority
Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
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Family
Hypnaceae
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Scientific Name
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Description
Genus Description - Plants rather slender, in low, ± shiny, green or yellow-green mats. Stems creeping, freely branched; branches spreading, somewhat flattened. Leaves oblong-lingulate or broadly elliptic to ovate, rounded or tmncate to emarginate or rarely acute, the lateral leaves ± asymmetric; margins sermlate to serrate (rarely entire, sometimes bifid-serrate); cells long-rhomboidal, smooth or minutely papillose at back because of projecting angles, rarely with 1 or more papillae on the lumina as well, not or slightly differentiated at the basal angles. Perichaetial leaves lanceolate, gradually or abmptly acuminate. Setae elongate, smooth or rarely roughened above; capsules inclined and asymmetric, ovoid- or oblong-cylindric, with a very short neck, often constricted below the mouth when dry; annulus differentiated; exothecial cells irregularly hexagonal, not collenchymatous; operculum conic, short-acuminate; exostome teeth lanceolate, cross-striolate below, papillose above, not furrowed, bordered, ± trabeculate at back; endostome consisting of a well-developed basal membrane, lanceolate, keeled, and ± perforate segments and 1-3 usually short cilia. Calyptrae cucullate.
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Discussion
Some parts ofthe genus, as it is commonly conceived, belong to Taxiphyllum in the Hypnaceae. The generic description given here is largely purged of Taxiphyllum characteristics. The relationship of the genus, and indeed its definition, needs investigation. The two species known from Mexico are closely related and not likely to be confused with any other genus owing to their blunt leaf tips of pecuhar marginal areolation and serration. Neither show any papillosity of leaf cells, at least in the few specimens available for smdy. This is a character that is difficult to establish. As in some species of Taxiphyllum the cell walls m a y be slightly thickened at the ends because of blunt tips. Microscopically the thickenings show up as points of light that resemble papillae formed by projecting cell ends. In G. ligulaefolius the cells seem to be papillose in this way; in G. laevifolius they do not.
Buck (1987b) has substituted Glossadelphus Fleisch. 1923 with an older name, Phyllodon Schimp. 1851. The two species listed here he placed in Taxiphyllum in the Hypnaceae.