Selaginella tarda Mickel & Beitel
Descripción
Stems suberect to erect, stramineous, 8–15 cm long, ca. 0.5–1.5 mm diam., articulate, not flagelliform, not stoloniferous, 2 times branched; rhizophores limited to proximal 1⁄3 of plant, stout, 0.5–0.8 mm diam.; leaves of two kinds (anisophyllous) throughout stem length; lateral leaves narrowly oblong, 1.5–2 mm long, bases truncate to subcordate basiscopically, cuneate acroscopically, margins finely denticulate, with narrow white borders, apices acute; median leaves ovate-lanceolate, nonpeltate, bases with one large auricle, borders narrow, white, margins finely denticulate, apices short-aristate; axillary leaves linear-lanceolate, exauriculate, margins denticulate; strobili quadrangular, 2–4 mm long; sporophylls dimorphic, the dorsal ones green, spreading, the ventral ones colorless, ascending, megasporophylls as large as lateral leaves, microsporophylls as small as median leaves; megasporangia single at base of strobili; microsporangia throughout strobili; megaspores cream to beige, 410–550 µm diam.; microspores beige.A
Forma de vida
TerrestreA
Ejemplar revisado
Col (Orcutt 4690, US p.p.). Dgo (Ortega 4287, US). Gro (Lorea 2842, NY). Jal (López 21289, NY). Méx (Hinton 2491, K, LL, PH, 8462, ENCB, F, LL, MICH, NY, PH, US). Mich (Díaz Barriga & García 6404, CAS; King & Soderstrom 4911, MICH, NY, TEX, US). Nay (Pennell 19966, PH). Oax (only the type). Sin (Breedlove 35658, CAS).A
Distribución
México (país) EndémicoA
Elevación
300 – 1400 mA
Tipo de vegetación
Selva alta, Bosque de neblina/mesófiloA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Selaginella tarda differs from S. sertata, S. schizobasis, and S. eurynota in smaller size, basally attached median leaves, denticulate leaf margins, and lack of flagelliform shoots. Among species with basally attached median leaves, S. silvestris has median leaves with two small, subequal auricles and exauriculate lateral leaves, S. stellata has auriculate, ciliate, lateral, axillary, and median leaves, whereas S. tarda has denticulate lateral leaves with truncate bases, denticulate median leaves with one large auricle (like S. stellata), and exauriculate, denticulate axillary leaves. See S. silvestris for comparison with that species. Selaginella tarda is closely related to S. kunzeana A. Braun, which is distributed from Costa Rica to Peru. In S. kunzeana, the median leaves have two auricles with the inner auricle narrower than the outer one; the leaves are denticulate, as in S. tarda, although the basiscopic margin of the lateral leaves is less toothed and somewhat curled.A