Didymodon

• 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.

• Family

  Pottiaceae

• Scientific Name

  Didymodon

• Description

  Genus Description - Plants in light- to dark- or ohve-green tufts. Stems up to 20 or even 6 0 mm high; central strand present, occasionally strong; axillary hairs usually with 1-2 brown stalk cells. Propagula occasional, usually globose to ellipsoidal, consisting of 1-10 cells. Leaves broadly concave or occasionally channeled at the costa above, ovate to long-lanceolate or long-triangular, rounded to narrowly acute at the apex, oblong and half-sheathing at base; margins entire or occasionally weakly dentate to crenulate, plane to revolute; costa ending several cells below the apex to excurrent, covered on both surfaces by short or elongate, smooth or papillose cells, in section semicircular or reniform, the dorsal stereid band usually weakly differentiated, the ventral band lacking or consisting of large-lumined substereids, guide cells 2-4, hydroids seldom present; upper cells subquadrate to rounded-angular, occasionally short-rectangular to rhombic, thin- to unevenly thick-walled, usually bulging on both surfaces, with papillae none or solid, simple to bifid, centered over the lumen to scattered; basal cells not to strongly differentiated, quadrate to rectangular, smooth or weakly papillose. Dioicous (or sometimes possibly rhizautoicous). Inflorescences terminal. Perigonia gemmiform. Perichaetial leaves ovate to long-lanceolate, often enlarged and commonly loosely sheathing; cells usually elongate to above the leaf middle. Setae elongate, twisted clockwise below, occasionally counterclockwise above; capsules ovoid to long-cyhndric; annulus of 1-3 rows of ± vesiculose cells, not deciduous; operculum short- to long-conic or conic-rostrate; peristome short, rudimentary, or long and twisted, consisting of 16 short teeth or 32 slender divisions, usuallydensely spiculose, occasionally spiral-striate or papillose, the basal membrane none or low. Calyptrae cucullate, smooth.