Selaginella lineolata Mickel & Beitel
Descripción
Stems suberect to erect, stramineous, 4.5–33 cm long, 0.2–0.9 mm diam., not articulate, with flagelliform branch and stem apices, stoloniferous, 2–3 times branched; rhizophores restricted to proximal 1⁄4 of stems or throughout stems on flagelliform plants, 0.1–0.3 mm diam.; leaves of two kinds (anisophyllous) throughout stem length; lateral leaves broadly ovate or oblong, 1.6–2.9 X 0.9–1.7 mm, bases rounded to subcordate, overlapping stems acroscopically, basiscopic bases auriculate to rounded, with the auricle overlapping the dorsal side of stems, margins nar rowly to widely hyaline or pale green, long-ciliate to denticulate proximally, denticulate or entire distally, apices acute, surfaces glabrous, with idioblasts; median leaves broadly ovate-elliptic to ovate-oblong, 0.8–1.8 X 0.5–1 mm, bases asymmetrically biauriculate, with inner bases rounded or auriculate, frequently ciliate, ciliate-denticulate, or entire, outer bases with a well developed and long-ciliate or entire auricle, margins hyaline, ciliatedenticulate, apices gradually long-acuminate to long-aristate, aristae 1⁄2 or less the lamina length, 0.1–0.5 mm long, both surfaces glabrous, with idioblasts above; axillary leaves similar to lateral leaves, exauriculate; strobili lax and flattened, dorsiventral, 2–7 mm long; sporophylls dimorphic, the dorsal ones green, spreading, the ventral ones hyaline to pale green, ascending; megasporangia generally in two ventral rows or at the base of ventral rows, or infrequently absent; microsporangia in two dorsal rows, frequently also at the distal part of ventral side of strobili, or strobili wholly microsporangiate; megaspores bone-white, with a slightly to moderately developed equatorial flange, striatereticulate, 275–340 µm diam.; microspores reddish orange.A
Forma de vida
Epipétrico, TerrestreA
Ejemplar revisado
Chis (Breedlove 48159, CAS p.p., ENCB p.p.). Col (McVaugh 16097, CAS, MICH, US). Gro (Rzedowski & McVaugh 26, MICH). Hgo (Sharp 45865, MEXU p.p., US). Jal (Pringle 2593a, BR, E, GH, M, NY, P, US). Méx (Hinton et al. 8212, DS, GH, MEXU p.p., NY p.p., U, US). Nay (McVaugh 18756, CAS, MICH, NY). Oax (Mickel 7331, NY). Qro (Rzedowski 46613, NY). Sin (Breedlove 35733, CAS, MICH, MO). Ver (Pringle 10806, ARIZ, CAS, F, GH, LL, MICH, MSC, TEX, UC, US).A
Elevación
900 – 2500 mA
Ecología y Hábitat
On shaded slopes, limestone outcrops, sandy soils, or banks of waterways.A
Tipo de vegetación
Bosque de neblina/mesófilo, Selva bajaB
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
Selaginella lineolata has glabrous lateral and median leaves with conspicuous idioblasts and white megaspores, which distinguish it from some other erect to suberect taxa with stoloniferous stems and flagelliform branches, e.g., S. bernoullii and S. porphyrospora.
Selaginella lineolata is closely related to S. prolifera, S. finitima (which see for discussion), and S. tenella. It can be distinguished from S. finitima by having idioblasts on the upper surfaces of both median and lateral leaves, flagelliform stems and branch apices, and conspicuous idioblasts and stomata on upper surfaces of dorsal sporophylls. Selaginella lineolata differs from S. prolifera in having flagelliform stem and branch apices, small, round auricles at the basiscopic bases of lateral leaves, and by short ciliatedenticulate projections on the acroscopic margins of the lateral leaves, which are less than 1⁄4 the width of the lamina (vs. more than 1⁄3 or even 1⁄2 in S. prolifera).
Selaginella tenella differs from S. lineolata by the median leaves elliptic to ovate-elliptic, with bases oblique and lacking definite outer auricles, leaves generally with broad hyaline margins, and sporophylls slightly dimorphic. In addition, S. lineolata has basal stolons from which the upright stems develop, whereas these are absent in S. tenella. In Mexico, S. lineolata is more robust than S. tenella.
The ciliate-denticulate leaves with conspicuous idioblasts of S. lineolata resemble leaves of S. stenophylla, which can be distinguished by suberect habit, stout rhizophores, absence of stolons, and more elongate lateral leaves that are 2–2.5 mm long and broadest at the bases. Differences in the lateral leaf size and shape are especially conspicuous when large stem leaves are compared. In S. lineolata, lateral leaves of the main stems are 2–2.5 mm long, whereas in S. stenophylla they are 3–3.5 mm long.
Pringle 10806, from Veracruz, is slightly different from typical S. lineolata by its more compact habit, lateral leaves perpendicular to the stem for most of the stem length, and obscure idioblasts; in general the acroscopic margins of the lateral leaves are more obviously long-ciliate. Specimens from Chiapas were among the tallest observed. One of them, Breedlove 48159, CAS, is atypical by its almost quadrangular to weakly flattened strobili, dorsal sporophylls not distinctly larger than the ventral sporophylls, lateral leaves with few short to long hairs at the basalmost portion of the basiscopic margin, and median leaf bases with two rather well developed and long-ciliate auricles. In these last characters it resembles S. hoffmannii Hieron. Red stem color was reported in living plants of S. lineolata (Hellwig & Whitaker 1373, NY), but this color fades on drying. Reddish to pink stems are typical of S. hoffmannii. That specimen differs from S. hoffmannii by its conspicuous to obscure idioblasts on the upper surfaces of the lateral leaves (vs. idioblasts absent), stems stramineous (vs. usually reddish to pink or occasionally stramineous), and stoloniferous leaves non-green or hyaline (vs. red-green). In general the median and lateral leaves of this collection fall within the morphological range of S. lineolata.
A
Selaginella lineolata is closely related to S. prolifera, S. finitima (which see for discussion), and S. tenella. It can be distinguished from S. finitima by having idioblasts on the upper surfaces of both median and lateral leaves, flagelliform stems and branch apices, and conspicuous idioblasts and stomata on upper surfaces of dorsal sporophylls. Selaginella lineolata differs from S. prolifera in having flagelliform stem and branch apices, small, round auricles at the basiscopic bases of lateral leaves, and by short ciliatedenticulate projections on the acroscopic margins of the lateral leaves, which are less than 1⁄4 the width of the lamina (vs. more than 1⁄3 or even 1⁄2 in S. prolifera).
Selaginella tenella differs from S. lineolata by the median leaves elliptic to ovate-elliptic, with bases oblique and lacking definite outer auricles, leaves generally with broad hyaline margins, and sporophylls slightly dimorphic. In addition, S. lineolata has basal stolons from which the upright stems develop, whereas these are absent in S. tenella. In Mexico, S. lineolata is more robust than S. tenella.
The ciliate-denticulate leaves with conspicuous idioblasts of S. lineolata resemble leaves of S. stenophylla, which can be distinguished by suberect habit, stout rhizophores, absence of stolons, and more elongate lateral leaves that are 2–2.5 mm long and broadest at the bases. Differences in the lateral leaf size and shape are especially conspicuous when large stem leaves are compared. In S. lineolata, lateral leaves of the main stems are 2–2.5 mm long, whereas in S. stenophylla they are 3–3.5 mm long.
Pringle 10806, from Veracruz, is slightly different from typical S. lineolata by its more compact habit, lateral leaves perpendicular to the stem for most of the stem length, and obscure idioblasts; in general the acroscopic margins of the lateral leaves are more obviously long-ciliate. Specimens from Chiapas were among the tallest observed. One of them, Breedlove 48159, CAS, is atypical by its almost quadrangular to weakly flattened strobili, dorsal sporophylls not distinctly larger than the ventral sporophylls, lateral leaves with few short to long hairs at the basalmost portion of the basiscopic margin, and median leaf bases with two rather well developed and long-ciliate auricles. In these last characters it resembles S. hoffmannii Hieron. Red stem color was reported in living plants of S. lineolata (Hellwig & Whitaker 1373, NY), but this color fades on drying. Reddish to pink stems are typical of S. hoffmannii. That specimen differs from S. hoffmannii by its conspicuous to obscure idioblasts on the upper surfaces of the lateral leaves (vs. idioblasts absent), stems stramineous (vs. usually reddish to pink or occasionally stramineous), and stoloniferous leaves non-green or hyaline (vs. red-green). In general the median and lateral leaves of this collection fall within the morphological range of S. lineolata.
A