Pteris L.
Descripción
Terrestrial, less commonly epipetric; rhizomes short-creeping to erect, compact, with scales at apices; fronds medium-sized to very large, clumped, monomorphic; stipes usually glabrous; blades pinnate to several times pinnate, often with basal pinnae exaggerated basiscopically, blades often pentagonal to pedate; laminae chartaceous to coriaceous, minor axes mostly glabrous, generally with slender, antrorse awns on the adaxial axes at base of pinnae (rachis awns), pinnules, and ultimate segments (pinna awns); veins free or netted, without included veinlets; sori marginal, protected by differentiated recurved margins (false indusia), mostly continuous except at sinuses and segment apices; paraphyses usually present, mixed with sporangia; spores each generally with an equatorial ridge, perispore lacking; x=29.A
Forma de vida
Epipétrico, TerrestreA
Distribución
México (país) Nativo y no endémicoA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Pteris is a pantropical genus of about 250 species, of which only about 60 are American. It is distinguished by its generally large fronds, marginal sori, and spores with an equatorial flange. Awns, which occur adaxially on the blade axes of many species of Pteris, are most conspicuous in the more laminated parts of the blades.
Molecular studies (Cranfill, unpubl.) suggest that the genus is polyphyletic. In particular, P. longifoliia and P. vittata are not closely related to the rest of Pteris, and probably not congeneric with the remaining Mexican species.
Excluded Species
Pteris tremula R. Br., Prodr. 154. 1810. Type. Australia. Port Jackson, Hunter’s River or Coal River, no specimen cited, “seen alive.”
Rhizomes compact, erect; rhizome scales linear-lanceolate, concolorous, black, 4–5 mm; fronds 45–150 cm, clumped; stipes ca. 1⁄2 the frond length, stramineous to reddish brown, glabrous; blades ovate, (2–)3–4-pinnate, 20–70 cm wide; ultimate segments linear, chartaceous to membranous, glabrous, margins toothed, segments 3–4 mm wide; awns blunt, ca. 0.1 mm long; veins free, sterile ones ending before margins; sori continuous along margins, interrupted at segment apices; spores tan; indusia 0.8–1 mm wide, paraphyses absent; 2n=232 (Aus).
Distribution. Terrestrial, montane cloud forests; 1600–1900 m. Mexico; Austr, NZ.
Specimen Examined. Qro (Díaz B. & Carranza 6560, IEB).
This species is known from a single collection from Querétaro. It seems most likely that it represents an escape from cultivation; the species is known in the wild only from Australia and New Zealand.
Among the free-veined, 2–3-pinnate species of Pteris, P. tremula resembles P. muricella and P. muricata in having the basal pinnae pinnate-pinnatifid beyond the basal pinnules but is distinct in the lamina being glabrous, membranous-chartaceous, the stipes lacking prickles, and the sori running nearly the entire segment length.A
Molecular studies (Cranfill, unpubl.) suggest that the genus is polyphyletic. In particular, P. longifoliia and P. vittata are not closely related to the rest of Pteris, and probably not congeneric with the remaining Mexican species.
Excluded Species
Pteris tremula R. Br., Prodr. 154. 1810. Type. Australia. Port Jackson, Hunter’s River or Coal River, no specimen cited, “seen alive.”
Rhizomes compact, erect; rhizome scales linear-lanceolate, concolorous, black, 4–5 mm; fronds 45–150 cm, clumped; stipes ca. 1⁄2 the frond length, stramineous to reddish brown, glabrous; blades ovate, (2–)3–4-pinnate, 20–70 cm wide; ultimate segments linear, chartaceous to membranous, glabrous, margins toothed, segments 3–4 mm wide; awns blunt, ca. 0.1 mm long; veins free, sterile ones ending before margins; sori continuous along margins, interrupted at segment apices; spores tan; indusia 0.8–1 mm wide, paraphyses absent; 2n=232 (Aus).
Distribution. Terrestrial, montane cloud forests; 1600–1900 m. Mexico; Austr, NZ.
Specimen Examined. Qro (Díaz B. & Carranza 6560, IEB).
This species is known from a single collection from Querétaro. It seems most likely that it represents an escape from cultivation; the species is known in the wild only from Australia and New Zealand.
Among the free-veined, 2–3-pinnate species of Pteris, P. tremula resembles P. muricella and P. muricata in having the basal pinnae pinnate-pinnatifid beyond the basal pinnules but is distinct in the lamina being glabrous, membranous-chartaceous, the stipes lacking prickles, and the sori running nearly the entire segment length.A