Adiantum tetraphyllum Humb. & Bonpl. ex Willd.
Descripción
Rhizomes short- to usually long-creeping, 3–5 mm diam.; rhizome scales golden brown, 2–3 X 0.3 mm, linear-lanceolate, sparsely denticulate; fronds clumped to distant, 35–100 cm long, arching; stipes atropurpureous, lustrous, 25–55 cm X 2–3 mm, 1⁄2–3⁄5 the frond length, with brown scales to 3 mm long; blades deltate, 2-pinnate, ca. 25–35 cm wide, each blade with a large conform terminal pinna; rachises atropurpureous, with numerous linear to lanceolate, denticulate scales to 1.5 mm long; pinnae 1–4(–5) alternate pairs, terminal pinnules elongate, pinnatifid; pinnules 15–40 X 5–7 mm long, tips acute to acuminate, falcate, non-articulate; veins free, forking, ending in teeth at the margins; indument adaxially absent, abaxially the surfaces with a few scattered hair-like scales; idioblasts conspicuous on both blade surfaces; sori mostly 3–6 per pinnule, confined to acroscopic margins; indusia 1–4 mm long, glabrous; 2n=58–60 (Jam).A
Forma de vida
TerrestreA
Ejemplar revisado
Chis (Breedlove 39999, DS, 56582, CAS, ENCB, NY, 57237, CAS; Matuda 18398, DS, MEXU; Purpus 6742, UC, US). Oax (Hallberg 1617, NY; Hernández G. 735, 1596, NY; Yatskievych 83-439a, NY). Ver (Copeland herb. 120, CAS, MEXU, MICH, UC; Purpus 2930, 15713, UC).
Unverified or Mistaken Reports. Nay (reported by Mickel & Beitel, 1988; not treated in the range by Mickel, 1992; González O. 6657, identified as this in CAS, is A. mcvaughii). Tab (reported by Magaña, 1992, possibly based on a misidentification).A
Unverified or Mistaken Reports. Nay (reported by Mickel & Beitel, 1988; not treated in the range by Mickel, 1992; González O. 6657, identified as this in CAS, is A. mcvaughii). Tab (reported by Magaña, 1992, possibly based on a misidentification).A
Elevación
150 – 350(– 1250) mA
Tipo de vegetación
Selva alta, Selva medianaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Among the bipinnate, idioblastic species with large pinnae, this taxon is distinctive in its combination of usually longcreeping rhizomes (0.5–2 cm between internodes), abaxial blade surfaces with scattered hair-like scales, numerous sori along the acroscopic pinnule margins, and pinnules that tend to curve toward the pinna tips. The indusia may be either glabrous (usually) or bear a few short hairs 0.1–0.3 mm long (as in Breedlove 37681, 42002, DS, from Chiapas). As commonly construed, A. tetraphyllum represents a species complex (see Kramer, Acta Bot. Neerl. 3: 481–486. 1954) that is especially diverse in South America. There is a very wide variety of material passing under this name in herbaria, some of it belonging to closely related species. We now regard all the specimens identified as A. fructuosum by Smith (1981) as A. tetraphyllum. Breedlove 48595 (CAS, NY), cited by Mickel and Beitel (1988) as A. trichochlaenum, has only a few weak hairs on a few indusia, and we now regard this also as A. tetraphyllum.A