Taxithelium

• Authority

  Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)

• Family

  Sematophyllaceae

• Scientific Name

  Taxithelium

• Description

  Genus Description - Plants slender to medium-sized, in green to yellowish or golden, often ± glossy, flat mats. Stems creeping, pinnately branched; paraphyllia none. Stem and branch leaves similar, crowded and usually somewhat complanate, ± concave, the dorsal and ventral leaves appressed, the lateral leaves larger, spreading, and often somewhat asymmetric, oblong-ovate or oblong-lanceolate, acute or sometimes rounded-obtuse or acuminate; margins sermlate (or rarely entire throughout or sharply toothed at the tips); costa none; cells linear, with several small papillae in a single row over the lumen, shorter and broader at base and nearly always differentiated at the basal angles and sometimes abmptly inflated. Perichaetial leaves erect, gradually or abmptly subulate from a lanceolate or ovate base, sermlate. Setae ± elongate, mostly smooth; capsules ± inclined and asymmetric, ovoid or oblong-cylindric, constricted below the mouth and at the short neck when dry; annulus persistent; operculum blunt or acute; exothecial cells not or slightly collenchymatous; stomata in the neck; exostome teeth inserted near the mouth, joined at base, lance-subulate, brownish-yellow and densely cross-striolate below, hyaline and papillose at the tips, with a zigzag median line, bordered, trabeculate at back; endostome papillose, with a fairly high basal membrane, keeled segments, and mostly single cilia. Calyptrae cucullate.

• Discussion

  The genus is aptly named in reference to papillae arranged in a row over the cell lumina.