Selaginella finitima Mickel & Beitel
Descripción
Stems suberect to erect, stramineous or greenish, 6–32 cm long, 0.4–0.9 mm diam., not articulate, occasionally with flagelliform stem and branch apices, stoloniferous, 2–3 times branched; rhizophores restricted to proximal portion of stems or throughout stem length on flagelliform plants, 0.1–0.4 mm diam.; leaves of two kinds (anisophyllous) throughout stem length; lateral leaves broadly ovate to ovate-oblong, 1.5–3.2 X 1.2–2.1 mm, bases rounded to subcordate, acroscopic bases strongly overlapping the stems, margins narrowly to widely hyaline or pale green, short- to long-ciliate proximally, denticulate distally, apices rounded, obtuse, or broadly acute, both surfaces glabrous, without idioblasts; median leaves broadly elliptical or suborbicular, 1.2–1.6 X 0.7–1 mm, bases with a single auricle, margins ciliate-denticulate or denticulate, apices gradually or abruptly long-aristate, aristae less than 1⁄2 the lamina length, 0.2–0.4 mm long, both surfaces glabrous, without idioblasts; axillary leaves similar to lateral leaves except more narrowly ovate and shortciliate to ciliate-denticulate proximally, bases rounded; strobili lax and flattened, dorsiventral, 2–10 mm long; sporophylls slightly dimorphic, the dorsal ones green, spreading, ventral ones hyaline to pale green, ascending; megasporangia generally occupying proximal 1⁄2 of two ventral rows or occasionally absent; microsporangia in two dorsal rows and along distal 1⁄2 of ventral rows, or strobili wholly microsporangiate; megaspores cream, with an equatorial flange, rugose to rugose-reticulate, 150–250 µm diam.; microspores orange.A
Forma de vida
Epipétrica, TerrestreA
Ejemplar revisado
Chis (Breedlove 35378, DS, 35379a, DS, ENCB, NY, 57707, CAS; Hoover 160, MO; Martínez et al. 25909, 26230, MEXU; Münch s.n., DS). Oax (Wendt et al. 2758-A, MEXU, NY). Tab (Magaña & Lorea 2166, ENCB). Ver (Dorantes 3970, XAL).A
Distribución
México (país) EndémicoA
Elevación
100 – 800 mA
Ecología y Hábitat
On limestone rocks and stream banks.A
Tipo de vegetación
Selva altaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Selaginella finitima has a distribution similar to that of S. prolifera and S. lineolata and all three species have median leaves with an outer auricle that is frequently ciliate, suberect to erect habit, stoloniferous stem bases, and frequently ciliate lateral leaves. Selaginella finitima differs chiefly by lacking idioblasts on the upper surfaces of the leaves and sporophylls, and lateral leaves with rounded, obtuse, or broadly acute apices. Some specimens of S. finitima (e.g., Wendt & Villalobos 2543 (the type), and Breedlove 35379a) develop vegetative growth from the tips of strobili. In addition, Wendt & Villalobos 2543 possesses leafy rhizophores. This feature lends support to the view that rhizophores are modified shoots capable of developing leaves, but that usually bear roots at the tip.A