Pireella pachyclada (Renauld & Cardot) Cardot

  • 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

    Pterobryaceae

  • Scientific Name

    Pireella pachyclada (Renauld & Cardot) Cardot

  • Description

    Species Description - Secondary stems of medium size, up to 4 cm high, dark-green, irregularly branched to pinnate-frondose above a stipitate base 1-1.5 cm high. Stipe leaves appressed, broadly ovate-acuminate, cordate at the insertion, 1-1.2 x 0.6-0.8 mm; costa extending to the apex. Upper leaves of secondary stems 1.0-1.6 x 0.8 mm, somewhat concave, oblong-ovate, abruptly short-acuminate, cordate at the insertion; margins plane, entire; costa ending in the apex; apical cells hexagonal to rhombic, 10-14 x 6-8 µm; median cells short-rectangular, rounded at the corners, 11-15 x 6-7 µm, those next to the costa elongate-rectangular; basal cells rectangular, 30-45 x 6-7 µm, thick-walled, weakly pitted, yellow; alar cells not distinctly differentiated. Branch leaves concave, ovate to oblong, acute to abruptly acuminate, cordate at the insertion, 1-1.4 x 0.6-0.8 mm; margins plane, weakly serrulate; costa ending in the acumen; upper cells rhombic to oval, 10-15 x 4-6 µm; median cells short-rectangular, 8-12 x 5-6 µm, those near the costa becoming elongate below; basal cells rectangular, 30-35 x 5 µm, thick-walled, yellow-brown; alar cells numerous, 10-12 µm, quadrate. Perichaetial leaves 2.2-2.5 x 0.8 mm, oblong, abruptly acuminate, often irregularly toothed at the shoulders; costa extending into the acumen. Setae 5-6 mm long, red-yellow, slightly roughened above; capsules 2-2.5 mm long, oblong-cylindric; exostome teeth hyaline with yellowish thickenings. Calyptrae, opercula, and spores not seen.

  • Discussion

    Fig. 532

    P. pachyclada (Ren. & Card.) Card., Rev. Bryol. 40: 18. 1913.

    Pirea pachyclada Ren. & Card., Bull. Soc. Roy. Bot. Belgique 41(1): 67. 1905.

    Similar stem and branch leaves, short, ovate median cells, and numerous quadrate alar cells distinguish P. pachyclada.

  • Distribution

    Rare, on tree trunks, less commonly on rock, in dense, moist forests at lower elevations; Campeche, Chiapas, Oaxaca, San Luis Potosi, Tabasco, Veracruz, Yucatan.—Mexico; Central America; Cuba.

    Cuba South America| Central America| Mexico North America|