Pireella pycnothallodes (Müll.Hal.) M.Fleisch.

  • Authority

    Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.

  • Family

    Pterobryaceae

  • Scientific Name

    Pireella pycnothallodes (Müll.Hal.) M.Fleisch.

  • Description

    Species Description - Plants medium-sized, to ca. 6 cm tall, in green to golden, thin to dense, epiphytic colonies. Primary stems creeping, filiform, usually naked or with small, reduced leaves, turning ca. 90° and becoming the upright secondary stem (stipe), the creeping stem continuing by a bud from near the base of the stipe, stipes frondose, subpinnately branched, erect, occasionally with flagellate branches; in cross-section with 6-8 rows of small thick-walled reddish cells surrounding gradually larger thin-walled cells, central strand none; paraphyllia none; pseudoparaphyllia filamentous, numerous; axillary hairs with a single rectangular brown basal cell and 3 elongate hyaline distal cells. Stipe leaves appressed, broadly triangular-ovate, 0.9-1.2 mm long, abruptly short-acuminate, slightly concave, decurrent; margins subentire to finely serrulate throughout, plane; costa single, percurrent to subpercurrent, often flexuose; cells oval, ca. 2-4:1, smooth, firm-walled, not or scarcely porose, becoming slightly longer in the acumen, becoming linear in lower 1/3 of leaf juxtacostally, and short-rectangular, porose and yellow at the insertion; alar cells quadrate in extensive areas, gradually merging with short upper cells. Branch leaves erect when dry, erect-spreading when moist, in obvious spiral rows, ovate, 0.85-1.3 mm long, gradually broad-acuminate, concave, not plicate, decurrent; margins serrulate at extreme apex, subentire below, plane above, narrowly recurved at base; costa single, subpercurrent to percurrent, flexuose; cells oval to rhomboidal, 2-3:1, smooth, firm-walled, not or scarcely porose, becoming longer toward the costa and somewhat so toward the margins, linear-flexuose in lower 1/3 juxtacostally, rectangular, porose and yellow toward the insertion; alar cells subquadrate in extensive areas, extending up the margins by >15 cells (and into the decurrencies). Asexual propagula not seen, except for microphyllous flagellate branches, to ca. 2 cm long, simple or rarely weakly branched. Dioicous, rarely fertile. Sporophytes not seen, reportedly setae 4-5 mm long and smooth, capsules 2-2.5 mm long.

  • Discussion

    5. Pireella pycnothallodes (Miill. Hal.) M. Fleisch., Hedwigia 59: 213. 1917; Dusenia pycnothallodes Müll. Hal., Hedwigia 36: 107. 1897. Plate 54, figures 1-7 Pirea pachyclcida Renauld & Cardot, Bull. Soc. Roy. Bot. Belgique 41(1): 67. 1905; Pireella pachyclcida (Renauld & Cardot) Cardot, Rev. Bryol. 40: 18. 1913. Pireella cubensis Cardot & Thér. in Cardot, Rev. Bryol. 40: 17. 1913, nom. nud., Cardot & Thér. in Thér., Mem. Soc. Cub. Hist. Nat. “Felipe Poey” 14: 359. 1940. Neolindbergia flagellifera Thér., Mem. Soc. Cub. Hist. Nat. “Felipe Poey” 14: 356. 1940. Discussion. Pireella pycnothallodes is distinct among the West Indian species because of the short cells of both the stipe and branch leaves. There is potential confusion with what is probably its most closely related species, P. filicina, because of the short branch leaf cells and decurrent stipe leaves in that species. However, P. filicina has squarrose stipe leaves with elongate cells and nondecurrent branch leaves. Pireella pycnothallodes is probably also closely related to the Central American P. mariae (Cardot in Renauld & Cardot) Cardot, but in that species the stipe leaves are much larger and the stipe and branch leaves are not decurrent.

  • Distribution

    Range. Mexico, Guatemala; Cuba, Jamaica (from a single collection, Buck 5555, NY); growing on tree trunks and shaded rocks, in humid forests, at ca. 1000 m.

    Mexico North America| Guatemala Central America| Cuba South America| Jamaica South America|