Vittaria bradeorum Rosenst.
Descripción
Rhizomes horizontal, compact, 1–1.5 mm diam.; rhizome scales clathrate, dimorphic in width and cell type, 3.5–7 mm long, from 2 cells (0.1 mm) to 12 cells (1 mm) wide at bases, apices narrowed to hair-like tip, 2 cells wide, appearing as a single hair (the central wall between the two cells) for ca. 1⁄3 the scale length, central cell walls often thicker and darker than cell walls near margins, or all walls thick and dark; fronds to 35 cm long, 1–2 mm wide at broadest point, margins recurved; midribs not visible on adaxial side, evident on abaxial side; paraphyses medium to dark red-brown, stout, 0.1 mm long, each with an enlarged apical cell (2 times or more longer than wide); spores tetrahedral.A
Forma de vida
Ocasionalmente epipétrica, EpífitaA
Ejemplar revisado
Chis (Breedlove 29912, DS, 56508, CAS). Col (Lott 2986, NY, UC). Gro (Lorea 1867, FCME; Velázquez 773, FCME). Oax (Mickel 6670, 7348, NY, UC; Pringle 5951, GH, NY). Ver (Copeland herb. 160a, MICH, UC; Nee et al. 25019, MEXU; Rowell et al. 17M664, UC, TEX).
Unverified, Doubtful, or Mistaken Reports. Pue (reported by Mickel & Beitel, 1988, probably based on Cruz Cisneros 1519, NY, which is V. graminifolia).
A
Unverified, Doubtful, or Mistaken Reports. Pue (reported by Mickel & Beitel, 1988, probably based on Cruz Cisneros 1519, NY, which is V. graminifolia).
A
Elevación
500 – 1500 mA
Tipo de vegetación
Bosque de neblina/mesófilo, Selva altaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Vittaria bradeorum has tetrahedral spores and evident midribs, and appears to be the earliest name for this species, now that the identity of V. dimorpha (= V. graminifolia) is known with more confidence. That name was synonymized by Lellinger (1972) under V. lineata, which differs in having bilateral spores. In recent years, V. dimorpha has been applied to specimens here called V. bradeorum (e.g., by Smith, 1981; Mickel & Beitel, 1988; Lellinger, 1989; Moran in Davidse et al., 1995), but in our opinion, the type of V. dimorpha has rhizome scales like those of V. graminifolia. Vittaria bradeorum and V. graminifolia have similar, tetrahedral spores.
The narrow-bladed, tetrahedral-spored Vittarias still need careful monographic revision in order to understand their species limits and geographical distribution. Vittaria bradeorum appears to be scattered on both the Atlantic and Pacific slopes of Mexico at low to middle elevations, mostly below elevations at which V. graminifolia occurs. The rhizome scales have very thick black cell walls (vs. thin and reddish brown in V. graminifolia), and the scale tips are very long and uniseriate at tips. Individual cells at mid-scale are about 5 times longer than wide, in comparison with cells at mid-scale in V. graminifolia, which are only a little longer than wide. A further difference between the two species is that the scales of V. bradeorum lack or have only a few inconspicuous marginal teeth, thus appearing to be nearly entire; in V. graminifolia, the scales appear to be prominently toothed, because the end walls of the marginal cells protrude away from the scale body. The narrow fronds and lack of stramineous adaxial midribs distinguish V. bradeorum from V. flavicosta.
Misidentified collections of this group abound in herbaria, and identifications, as given in citations by Smith (1981), Mickel & Beitel (1988), and Palacios-Rios (1992), have also been changed in a number of cases. For example, most of the specimens cited by Smith (1981) for V. dimorpha are now considered to be V. flavicosta; Mickel 4339 (NY, UC), Mickel 6222 (NY), and Pringle 5951 (NY), cited by Mickel and Beitel (1988) as V. dimorpha, are V. graminifolia; Mexia 9133a (see below) is not V. dimorpha but V. flavicosta; and Purpus 1966 (UC), cited by Palacios-Rios (1992) as V. dimorpha, is V. graminifolia.A
The narrow-bladed, tetrahedral-spored Vittarias still need careful monographic revision in order to understand their species limits and geographical distribution. Vittaria bradeorum appears to be scattered on both the Atlantic and Pacific slopes of Mexico at low to middle elevations, mostly below elevations at which V. graminifolia occurs. The rhizome scales have very thick black cell walls (vs. thin and reddish brown in V. graminifolia), and the scale tips are very long and uniseriate at tips. Individual cells at mid-scale are about 5 times longer than wide, in comparison with cells at mid-scale in V. graminifolia, which are only a little longer than wide. A further difference between the two species is that the scales of V. bradeorum lack or have only a few inconspicuous marginal teeth, thus appearing to be nearly entire; in V. graminifolia, the scales appear to be prominently toothed, because the end walls of the marginal cells protrude away from the scale body. The narrow fronds and lack of stramineous adaxial midribs distinguish V. bradeorum from V. flavicosta.
Misidentified collections of this group abound in herbaria, and identifications, as given in citations by Smith (1981), Mickel & Beitel (1988), and Palacios-Rios (1992), have also been changed in a number of cases. For example, most of the specimens cited by Smith (1981) for V. dimorpha are now considered to be V. flavicosta; Mickel 4339 (NY, UC), Mickel 6222 (NY), and Pringle 5951 (NY), cited by Mickel and Beitel (1988) as V. dimorpha, are V. graminifolia; Mexia 9133a (see below) is not V. dimorpha but V. flavicosta; and Purpus 1966 (UC), cited by Palacios-Rios (1992) as V. dimorpha, is V. graminifolia.A