Adiantum amblyopteridium Mickel & Beitel
Descripción
Rhizomes short-creeping, to 5 mm diam.; rhizome scales somewhat bicolorous, light brown with cells toward middle having thickened, dark brown cell walls, 2–3 X 0.3–0.5 mm, margins entire; fronds clumped, 60–100 cm long, arching; stipes atropurpureous, 30–60 cm X 2–3 mm, 1⁄3–2⁄3 the frond length, with pectinate scales but these abraded and stipes then subglabrous; blades deltate, 2-pinnate, each blade with a conform terminal pinna, 30–50 cm wide; rachises with persistent, tan, lanceolate scales 1–1.5 mm long, these ciliate or denticulate at bases; pinnae 6–9 pairs, 20–35 X 3–4 cm, terminal pinnules non-conform, pinnatifid, elongate, basal pinnules triangular or flabellate; pinnules (largest) 12–20 X 8–10 mm, rounded or obtuse at apices, non-articulate; veins free, forking, ending in minute teeth in sterile pinnules or portions of pinnules; indument adaxially absent, abaxially the laminar surfaces with scattered, tan, pectinate scales 0.8 mm long; idioblasts present and conspicuous on both surfaces; sori ca. 6–10 per pinnule, on acroscopic and distal margins; indusia 2–3 mm long, oblong to lunate, glabrous.A
Forma de vida
TerrestreA
Ejemplar revisado
Oax (Conzatti et al. s.n., MEXU, 3147, US; Mickel 5163, NY–3 sheets). QR (Palacios-Rios 3661, XAL).A
Distribución
México (país) EndémicoA
Ecología y Hábitat
Wooded stream banks.A
Categoría IUCN
No incluidaA
Categoría NOM-059-SEMARNAT-2010
No incluidaB
Discusión taxonómica
Adiantum amblyopteridium is distinguishable from the other bipinnate, idioblast-bearing species with small pinnules (A. pulverulentum, A. trichochlaenum) by the combination of several sori per pinnule, glabrous indusia, and broadly rounded pinnule tips. Adiantum amblyopteridium may be one parent of A. oaxacanum(which see). These two taxa and the other presumed parent, A. obliquum, have been collected near each other in Dto. Pochutla, Oaxaca.A