Selaginella arsiclada Valdespino
Descripción
Stems creeping, green to stramineous, 2–12 cm long, 0.3–0.5 mm diam., not articulate, not flagelliform, not stoloniferous, 2–3 times branched; rhizophores borne throughout stem length, 0.2–0.3 mm diam.; leaves of two kinds (anisophyllous) throughout, surfaces green or yellowish to brown when old; lateral leaves broadly ovate to ovate-deltate on main stems, ovate-oblong to oblong on branches, 1–1.4 X 0.5–0.9 mm, margins whitish in a band 1(–2) cells wide, short-ciliate (to long-ciliate basiscopically), denticulate distally, apices obtuse; median leaves ovate, 0.6–0.8 X 0.4–0.6 mm, bases oblique to slightly cordate, margins whitish in a band 3–4 cells wide, short-ciliate most of the length, denticulate distally, apices broadly acute; axillary leaves similar to lateral ones except bases more obviously cordate; strobili quadrangular, 2–5 mm long; sporophylls monomorphic; megasporangia in two ventral rows; microsporangia in two dorsal rows; megaspores white, smooth, 200–240 µm diam.; microspores orange with capitate projections, 21–28 µm diam.A
Forma de vida
Epipétrica, TerrestreA
Ejemplar revisado
Qro (Díaz Barriga 4267, NY). Ver (Purpus 8463, MO p.p., 8464 p.p., UC, US, 117 [10117], US; Sperling 4049, XAL).A
Distribución
México (país) EndémicoA
Elevación
200 – 600 mA
Ecología y Hábitat
On dry clay at river banks in seasonally dry areas, or on soil and rocks in moist forests.A
Tipo de vegetación
Selva medianaB
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
Selaginella arsiclada does not seem closely related to other Mexican Selaginellas. It may be confused with S. reflexa and S. schiedeana because of its creeping habit, axillary rhizophores that are borne throughout the stems, ovate median leaves, and whitish leaf margins. Selaginella arsiclada can be distinguished from the other two species by its median leaves with broadly acute (vs. long-acuminate to aristate) apices, short-ciliate or denticulate margins proximally, and denticulate margins distally (not long- to short-ciliate throughout). It differs further from S. reflexa in the axillary leaves on the main stems being similar to the lateral leaves (vs. obovate in S. reflexa), and from S. schiedeana by its lateral leaves with apices gradually tapering (vs. almost equal in width to the base in S. schiedeana).A