Plagiogyria (Kunze) Mett.
Descripción
Rhizomes rather stout, suberect, dictyostelic, lacking scales and hairs, sometimes stoloniferous; roots wiry; fronds dimorphic, the fertile ones more erect, with longer stipes, and with narrower pinnae, the sterile ones pinnatisect to barely pinnate and the pinnae adnate, crown-forming, erect to arching, glabrous at maturity, young fronds covered with a gelatinous secretion; stipes with 3 vascular bundles at base, fusing distally to a V- or U-shape, stipe bases flared or slightly expanded, blackish,persistent, subtriangular in cross section, covering the rhizomes, bearing 2 rows of obscure to prominent gland-like protuberances (aerophores) at their bases; blades chartaceous to subcoriaceous, pinna margins remotely serrulate to biserrate, especially at pinna tips; veins free, simple or 1-forked, occasionally 2-forked; fertile fronds with contracted pinnae, sporangia at maturity seemingly covering abaxial surfaces of fertile blades, actually in a line along both sides of costa, without true indusia, margins scarious and recurved, protecting the sporangia when young; sporangia sometimes with hair-like paraphyses, sporangial stalks of 4–6 rows of cells; annuli oblique, uninterrupted by stalks; spores tetrahedralglobose, with surface smooth or irregularly tuberculate, sometimes with scattered globules; gametophytes epigeal, chlorophyllous, cordate or somewhat elongate; x=66.A
Forma de vida
TerrestreA
Distribución
México (país) Nativo y no endémicoA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Plagiogyria is a genus of generally high elevations, and the species often grow in cloud forests or in boggy areas with por soils. According to most accounts, Plagiogyria comprises about 40–50 species, mostly of southern and eastern Asia (Japan to Malesia, China, and the Himalayas), but most authors agree that this number is inflated (e.g., see Kramer in Kubitzki, 1990). A more realistic estimate is 15–20 species worldwide, and Zhang and Nooteboom (1998) recognized only 11. In the New World there are at most six species (Lellinger, 1971), but only one is widespread. We feel that even six is too high, that a better estimate is three; Zhang and Nooteboom (1998) recognized only a single American species, but their treatment stressed more the Asian taxa. The characters of vein branching and toothing used to separate the American species by Lellinger seem tenuous and insufficient. More work, especially population field studies, is needed to evaluate better the American species of this genus.
The genus has often been thought to be related to the Osmundaceae, but recent molecular data support the conclusión that it is more closely related to the tree ferns, Dicksoniaceae and Cyatheaceae (Pryer et al., 1995; Wolf et al., 1999). Plagiogyria is, however, a rather isolated genus, phylogenetically. It is is distinguished by having dimorphic fronds, lack of indusia, flared stipe bases, and sporangia with rather thick (ca. 6-seriate) sporangial stalks and slightly oblique annuli. There is a superficial resemblance to certain dimorphic species of Blechnum, under which name specimens often are mistakenly identified.
A
The genus has often been thought to be related to the Osmundaceae, but recent molecular data support the conclusión that it is more closely related to the tree ferns, Dicksoniaceae and Cyatheaceae (Pryer et al., 1995; Wolf et al., 1999). Plagiogyria is, however, a rather isolated genus, phylogenetically. It is is distinguished by having dimorphic fronds, lack of indusia, flared stipe bases, and sporangia with rather thick (ca. 6-seriate) sporangial stalks and slightly oblique annuli. There is a superficial resemblance to certain dimorphic species of Blechnum, under which name specimens often are mistakenly identified.
A