Athyrium arcuatum Liebm.
Descripción
Rhizomes erect; rhizome scales 6–8(–10) X 0.8–1 mm, brown, some with black streaks or slightly bicolorous, lanceolate, entire; fronds clumped; stipes 20–55 cm long, 1⁄2 the frond length, stramineous, glabrous except with scattered scales at bases; rachises stramineous, glabrous; blades bipinnate-pinnatifid, 24–40 X 15–44 cm, deltate-lanceolate, basal pinnae not deflexed, (6.5–)8–17 X (2.5–)3.5–8 cm, apices pinnatifid, basal basiscopic pinnule short, 0.6–1.8 cm long, largest basiscopic pinnules 1.5–4 cm long, basiscopic pinnules larger than acroscopic ones, costae and pinnule surfaces glabrous or with scattered black hair-like scales, wings along costae and segment midribs conspicuous adaxially, often with a tooth 0.5–0.8 mm long at vein branching, pinna margins serrately incised to laciniate; sori linear to hooked; indusia 0.5–0.8(–1) X 0.1–0.3(–0.5) mm, entire or with occasional fimbriae.A
Forma de vida
TerrestreA
Ejemplar revisado
Chis (Breedlove 27215, NY). DF (Rzedowski 34731, IEB). Gro (Lorea 4103, ENCB). Gto (Ventura & López 9177, IEB). Hgo (Medina-Cota & Barrios 3728, NY). Jal (Rzedowski 27527, ENCB, NY). Méx (Molseed 545, UC). Mich (Rzedowski 46181, IEB). Mor (Lyonnet 2508, MEXU). Nay (Téllez 12776, MEXU). Oax (Mickel 4696, NY). Pue (Weber 781, ENCB). Qro (Díaz B. & Carranza 7339, IEB). Ver (Ventura 9013, CAS, DS, ENCB, IEB, MO, NY, UAMIZ, XAL).A
Elevación
1800–3200 mA
Ecología y Hábitat
In moist woods and along streams.A
Tipo de vegetación
Bosque de neblina/mesófiloA
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
Two members of the Athyrium filix-femina complex occur in Mexico, and they have been considered as distinct species by Mickel and Beitel (1988). The name Athyrium arcuatum has been applied to large plants with deltate blades and basal pinnae largest, arcuate upwards at their distal ends.
In contrast, the name Athyrium bourgeaui has been applied to plants with blades at least slightly reduced proximally. Unfortunately, there seem to be no characters that distinguish the two other than blade shape, and there are many intermediate specimens. Specimens from northwestern Mexico with reduced blade bases may be the same as what is called Athyrium filixfemina var. californicum Butters or var. cyclosorum Rupr. and may well be the same as A. bourgeaui since there seem to be no characters to distinguish them. Similarly, the same extremes in blade form seem to occur farther south in Central and South America. Much more work is needed on this complex in Latin America before we can apply specific names with confidence.
A
In contrast, the name Athyrium bourgeaui has been applied to plants with blades at least slightly reduced proximally. Unfortunately, there seem to be no characters that distinguish the two other than blade shape, and there are many intermediate specimens. Specimens from northwestern Mexico with reduced blade bases may be the same as what is called Athyrium filixfemina var. californicum Butters or var. cyclosorum Rupr. and may well be the same as A. bourgeaui since there seem to be no characters to distinguish them. Similarly, the same extremes in blade form seem to occur farther south in Central and South America. Much more work is needed on this complex in Latin America before we can apply specific names with confidence.
A