Pleopeltis × tricholepis (Mickel & Beitel) A.R.Sm. & Tejero, Bot. Sci. 92(1): 48. 2014
Descripción
Planta inter Pleopeltim mexicanam et Polypodium thyssanolepidem hybrida a parentibus frondium divisione intermedia et sporis abortivis differt. [Gr., thrix, hair, and lepis, scale, referring to the ciliate (comose) scales and also a combi nation of the parental species epithets (Polypodium trichophora = Pleopeltis mexicana)].
Rhizome creeping, 1.5-2 mm diam.; rhizome scales deeply fimbriate, dimorphic; rhizome scales 1.5-2 mm long, bicolorous with brown-black center and narrow pale brown margin, occasionally with long brown hairs from central point; scales at base of stipe 2-3 mm long, pale brown with or without short dark central streak; fronds distant to nearly clumped; stipe ca. 1/2 of frond length, castaneous to atropurpureous, densely clothed with bicolorous scales, reddish brown with pale brown laciniate margin, round (0.5-0.8 mm wide) to lanceolate (1.5-2 mm long); blade irregularly pinnatisect, 16-18 cm long, 5-6 cm wide, broadest at base; pinnae or lobes 4-6 pairs, 5-7 mm wide; abaxial surface with scattered to dense, deeply fimbriate scales, mostly lanceolate (1.0-1.5 mm long), some round (0.8-1.0 mm wide), with brown center grading to whitish margin; midrib dark with lanceolate scales, 1.5-2 mm long; adaxial surface with sparse, deeply lacerate, lanceolate scales; sori round to slightly ovate, surrounded by laminar scales; soral scales rare, peltate to cordate, lanceolate, 0.8 mm long with pale brown point of attachment and lighter brown fimbriate margin; spores abor tive.
A
Rhizome creeping, 1.5-2 mm diam.; rhizome scales deeply fimbriate, dimorphic; rhizome scales 1.5-2 mm long, bicolorous with brown-black center and narrow pale brown margin, occasionally with long brown hairs from central point; scales at base of stipe 2-3 mm long, pale brown with or without short dark central streak; fronds distant to nearly clumped; stipe ca. 1/2 of frond length, castaneous to atropurpureous, densely clothed with bicolorous scales, reddish brown with pale brown laciniate margin, round (0.5-0.8 mm wide) to lanceolate (1.5-2 mm long); blade irregularly pinnatisect, 16-18 cm long, 5-6 cm wide, broadest at base; pinnae or lobes 4-6 pairs, 5-7 mm wide; abaxial surface with scattered to dense, deeply fimbriate scales, mostly lanceolate (1.0-1.5 mm long), some round (0.8-1.0 mm wide), with brown center grading to whitish margin; midrib dark with lanceolate scales, 1.5-2 mm long; adaxial surface with sparse, deeply lacerate, lanceolate scales; sori round to slightly ovate, surrounded by laminar scales; soral scales rare, peltate to cordate, lanceolate, 0.8 mm long with pale brown point of attachment and lighter brown fimbriate margin; spores abor tive.
A
Ejemplar revisado
Oax (Mickel 3873, NY, UC).A
Distribución
México (país): Oaxaca NativoB
Elevación
1900 mB
Tipo de vegetación
Bosque de otro tipoA
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
(In relation to the synonym Pleopodium tricholepis) This specimen, exhibiting hybrid characters of abortive spores and irregular blade lobes, appears to represent a hybrid between the pinnatisect species Polypodium thyssanolepis and a simple-bladed species of Pleopeltis. Although P. conzattii was the only species of Pleopeltis found at the same locality, the presence of round scales and the absence of black-centered rachis scales makes that species unlikely as a possible parent. The few soral scales are not strongly and deeply bicolorous as one would expect in hybrids involving P. polylepis, P. crassinervata, P. astrolepis, and P. interjecta. Pleopeltis mexicana, with lightly colored soral scales, long stipe, and occasional tufts of long hairs on the rhizome scales, is probably the other parent.
Another specimen (Mexico, DF, Angostura, 2600 m, Lyonnet 3414, US) has rhizome scales monomorphic and larger (2-2.5 mm long vs. 1.5-2), blade scales darker, farther apart (sparse), and smaller (0.8-1 mm long vs. 1-1.5), pinna pairs fewer, and soral scales dark-centered (vs. pale brown-centered). Tentatively we consider it as a variant of x P. tricholepis, but conceivably it may represent the hybrid of Pleopeltis interjecta x Polypodium thyssanolepis.A
Another specimen (Mexico, DF, Angostura, 2600 m, Lyonnet 3414, US) has rhizome scales monomorphic and larger (2-2.5 mm long vs. 1.5-2), blade scales darker, farther apart (sparse), and smaller (0.8-1 mm long vs. 1-1.5), pinna pairs fewer, and soral scales dark-centered (vs. pale brown-centered). Tentatively we consider it as a variant of x P. tricholepis, but conceivably it may represent the hybrid of Pleopeltis interjecta x Polypodium thyssanolepis.A