Adiantum mcvaughii Mickel & Beitel
Descripción
Rhizomes short-creeping, 4–7 mm diam.; rhizome scales dark brown, lustrous, 1.5–2 X 0.1–0.3 mm, margins sparsely denticulate to entire; fronds spaced ca. 5 mm apart, 35–65 cm long, arching; stipes atropurpureous, lustrous, 15–30 cm X 1–3 mm, ca. 1⁄2 the length of fronds, with narrow brown scales to 2 mm long; blades broadly ovate, 2-pinnate, 16–35 X 19–30 cm; rachises castaneous to atropurpureous, with a mixture of hairs and hair-like scales; pinnae 2–5 pairs plus a conform terminal one, alternate; pinnules not much reduced at the bases or tips of pinnae, the largest 20–34 X 10–15 mm, tips rounded, the sides forming nearly right angles at pinnule bases, non-articulate; veins free, forking, ending in small teeth; indument adaxially absent, abaxially the costae with a mixture of hairs and hair-like scales, also with scattered golden hairs 0.5–0.8 mm along the veins and tissue between veins, or blades glabrous; idioblasts present on both blade surfaces; sori mostly 3–10 per pinnule, along both the acroscopic and distal margins of pinnules, also sometimes along basiscopic side toward pinnule tips; indusia 2–4 mm long, glabrous.A
Forma de vida
TerrestreA
Ejemplar revisado
Chis (Breedlove 48568, CAS). Nay (Alava & Cook 1521, UC, 1603, MEXU, UC; González Ortega 6657, CAS; McVaugh 19018, MEXU, 19196, CAS, IEB, MICH; Mexia 1030, MICH, MO, NY, UC; Miller & Téllez 3198, MO, UC; Téllez & Miller 10494, MEXU, MO). Unverified, Doubtful, or Mistaken Reports. Jal (Maciel s.n., GUADA; Villalobos 164, ZEA, both cited by Mickel & Beitel, 1988, but not verified). Mich (Rzedowski 46175, IEB; Santos Martínez 1999, IEB, both cited by Mickel, 1992, but not verified).
A
A
Distribución
México (país) EndémicoA
Elevación
20 – 1000(– 2900) mA
Ecología y Hábitat
Growing in damp soil.A
Tipo de vegetación
Selva alta, Selva medianaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
It is surprising that there are two collections of this species from very high elevations in Michoacán, at 2750 and 2900 m; ordinarily this group of Adiantum occurs below 1500 m. It is most closely related to A. latifolium, differing by the blunt, larger pinnules, more greenish color of the dried blades, and shortercreeping rhizomes. Most specimens, including the type, bear a few, scattered, golden hairs on the veins abaxially. The sole specimen seen from Chiapas, from the Central Depression, is noticeably disjunct from the other collections, but appears not to differ significantly from specimens further north.A