Adiantum villosum L.
Descripción
Rhizomes short-creeping, 5–8 mm diam.; rhizome scales dark brown, denticulate, 1.5–2 X 0.1–0.3 mm; fronds clumped, 50–100+ cm long, arching; stipes atropurpureous, lustrous, 40–55 cm X 2–4 mm, ca. 2⁄3 of the frond length, with numerous brown hair-like and lanceolate scales 1–2 mm long; blades ovate, 2-pinnate, 25–45 X 25–40 cm wide, with conform terminal pinna; rachises atropurpureous, with lanceolate to hair-like, denticulate scales; pinnae 3–6 pairs, 15–25 X 4–6 cm, alternate; pinnules 20–35 X 8–12 mm, sides of proximal and median pinnules forming right angle at pinnule bases, distal pinnules on each pinna about 1⁄2 the length of the longest pinnules, terminal pinnules hastate, non-articulate; veins free, forking, ending in small teeth (sterile pinnules); indument adaxially absent, abaxially the surfaces with scattered tan pectinate scales to 1 mm long; idioblasts conspicuous on both blade surfaces; sori 10–12 per pinnule, along both acroscopic and distal part of basiscopic margins; indusia 1–4 mm long, oblong or slightly arcuate, glabrous.
A
A
Forma de vida
TerrestreA
Ejemplar revisado
Camp (Zamora C. & Méndez D. 5247, XAL). Chis (Breedlove 32577, DS, NY; Fisher 35400, NY, US). Gro (Velázquez 616, FCME). Oax (Cortés 6, ENCB, UAMIZ; Mickel 5773, NY, UC). QR (Torres et al. 66, UAMIZ). Tab (Matuda 3205, US). Ver (Nee 23614-b, XAL; Rzedowski 18890, ENCB, MEXU, NY).A
Elevación
0 – 800 mA
Ecología y Hábitat
Wooded slopes along streams.A
Tipo de vegetación
Selva alta, Selva medianaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
The acute-tipped pinnules with right-angle bases distinguish this taxon among the bipinnate, idioblastic species with large pinnules and hair-like scales on the blades. Putative hybrids with A. trichochlaenum, having malformed spores and large pinnae with papillate emergences on the indusia, have been found in Chiapas (Purpus 6864, NY, UC, US). See A. pulverulentum for discussion of hybrids with that species. Specimens of A. villosum from the West Indies and some from Mesoamerica have the sori nearly continuous along the acroscopic pinna margins, while those from Mexico and most from Guatemala and Honduras have the sori interrupted into ca. 5–7 units, each mostly 2–4 mm long.A