Pseudotaxiphyllum

• 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

  Plagiotheciaceae

• Scientific Name

  Pseudotaxiphyllum

• Description

  Genus Description - Plants medium-sized, in thin to dense, light- to yellow-green, dull to glossy mats. Stems creeping, simple or often sparsely and iregularly branched; cortical cells small and thick-walled with a central strand sometimes present; rhizoids smooth, in clusters below the leaf insertions; pseudoparaphyllia none. Asexual reproductive bodies sometimes present in axillary clusters at or below the stem tips, elongated (0.1-0.5 mm long), twisted-vermiform, with 1-5 acute teeth, and smooth-celled or resembling the parent plant in miniature (0.8-1.2 mm long). Stem and branch leaves similar, somewhat rigid, crowded, erect-spreading to squarrose, sometimes upturned-homomallous, occasionally complanate, smooth or undulate, flat or concave, symmetric to asymmetric, non-decurrent, lanceolate to ovate, acute, often abmptly so, to acuminate; margins plane to erect, sermlate to serrate; costa lacking or short and double; cells often flexuose, firm-walled, linear-fusiform, smooth, the walls not pitted; alar regions not differentiated or with numerous quadrate to short-rectangular cells. Dioicous or sometimes autoicous, usually sterile. Perigonia along the stems. Perichaetia at base of stems; perichaetial leaves small, lanceolate to ovate, acuminate to abmptly filiform-acuminate, plane-margined. Setae smooth, elongate, straight or sometimes curved, twisted, red to reddish-brown; capsules cernuous to pendulous, straight to subarcuate, dark brown to dark red, smooth to wrinkled, contracted below the mouth and wrinkled at the neck when dry; opercula conic to short-rostrate, shorter than the µm; annulus deciduous, of 2-3 rows of cells; exostome teeth cross-striolate below, papillose above, bordered, trabeculate at back; endostome with a low to high basal membrane, keeled segments, and cilia shorter than the segments in groups of 1-3. Spores spherical to ovoid, minutely papillose. Calyptrae naked.

• Discussion

  Recently segregated from Isopterygium (Iwatsuki, 1987), Pseudotaxiphyllum has cortical cells of stems and branches small and thick-walled and smooth rhizoids below the leaf insertions, as in that genus, but it lacks pseudoparaphyllia and has annulate capsules. The plants may be dioicous or sometimes autoicous, but sex organs and sporophytes have not yet been found in two of the Mexican species.