Pleopeltis × melanoneuron Mickel & Beitel, Amer. Fern J. 77(1): 25. 1987
Descripción
Planta inter Pleopeltim crassinervatam et P. fallacem frondium divisione rhizomatisque squamis intermedia nervis nigris laminaeque apice acuta abstat. (Gr., melos, referring to the dark secondary veins at the base of the blade)
Rhizome creeping, 0.5-0.8 mm diam.; rhizome scales late, with dark brown to black center and narrow pale from central point with 0.5-0.8 mm reddish brown hairs, distant; stipe ca. 1/4 of frond length, round, atropurpureous; pinnatifid, 4.3-5.5 cm long, 1.0-1.8 cm wide, oblanceolate, lobes with irregular teeth at tips; abaxial and adaxial briate scales, some lanceolate (0.5 mm long), some with brown center and pale brown margin; midrib dark scales, 0.8-1.0 mm long, similar in color to laminar blackened, especially at base; soral scales extremely light brown with fimbriate margin; sori slightly oval; reproductive status uncertain, specimen with juvenile sporangia and mature sporangia open with no spores present.A
Rhizome creeping, 0.5-0.8 mm diam.; rhizome scales late, with dark brown to black center and narrow pale from central point with 0.5-0.8 mm reddish brown hairs, distant; stipe ca. 1/4 of frond length, round, atropurpureous; pinnatifid, 4.3-5.5 cm long, 1.0-1.8 cm wide, oblanceolate, lobes with irregular teeth at tips; abaxial and adaxial briate scales, some lanceolate (0.5 mm long), some with brown center and pale brown margin; midrib dark scales, 0.8-1.0 mm long, similar in color to laminar blackened, especially at base; soral scales extremely light brown with fimbriate margin; sori slightly oval; reproductive status uncertain, specimen with juvenile sporangia and mature sporangia open with no spores present.A
Ejemplar revisado
Veracruz, Altotonga, 1938, M. B. Foster 14 (US!).A
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
The type of P. x melanoneuron was originally a paratype of Polypodium sordidulum. However, it differs in several characters that point to a separate origin as the hybrid of Pleopeltis fallax and P. crassinervata. It resembles P. x sordidula in its irregular blade division and both lanceolate and round scales on the adaxial and abaxial laminar surfaces. The evident lateral veins, blackened at their bases, differ significantly from the obscure lateral veins of P. x sordidula and point to P. crassinervata, with its black lateral veins, as its simple-bladed parent. The rhizome scales of P. x melanoneuron are definitely lanceolate, bicolorous, and larger than those of P. x sordidula, again pointing to P. crassinervata with its longer, lanceolate rhizome scales with wider pale margins than in P. astrolepis. The stipe in P. x sordidula is flattened (from P. astrolepis with its strongly flattened stipe), whereas in P. x melanoneuron the stipe is terete (since both P. fallax and P. crassinervata have terete stipes). The rachis scales in P. x melanoneuron are lanceolate and non-comose (similar to P. crassinervata), whereas in P. x sordidula they are round and comose (both P. fallax and P. astrolepis have comose rachis scales, round in the former and lanceolate and round in the latter). The oblanceolate blade of P. x melanoneuron is acute at the apex and has scales with dark, non-clathrate centers, whereas P. x sordidula has a linear-lanceolate blade with an acuminate apex and scales with dark, semiclathrate centers.A