Selaginella neospringiana Valdespino, 2015

Valdespino, Ivan A., 2015, Novelties in Selaginella (Selaginellaceae - Lycopodiophyta), with emphasis on Brazilian species, PhytoKeys 57, pp. 93-133 : 96-99

Selaginella neospringiana Valdespino sp. nov. Figures 4 , 5 , 6

Diagnosis.

Selaginella neoespringiana differs from Selaginella vestiens Baker by the median leaves elliptic (vs. ovate or ovate-lanceolate), each 0.6-0.8 × 0.3-0.45 mm (vs. 0.9-2.0 × 0.4-1.0 mm) with bases rounded (vs. bases truncate or with the inner bases truncate and the outer bases auriculate or bases oblique), hyaline margins 10-30 µm (vs. 100-180 µm) wide and long-ciliate (vs. dentate to short-ciliate), each cilia 80-180 µm (vs. 40-50 µm), the lateral leaves ovate to ovate-elliptic (vs. ovate-deltate) with the upper surfaces glabrous (vs. with submarginal prickle- or tooth-like projections along basiscopic halves), the basiscopic margins entire on proximal ⅔ and denticulate along distal ⅓ (vs. dentate throughout), and sporophylls short-ciliate (vs. dentate).

Type.

BRAZIL. Rio de Janeiro: Petrópolis, Morro de Cubiçado, Gularte area, [ca. 1650 m], 7 Jul 1879, A. Glaziou 11723 (holotype: C!; isotypes: BM!, P [P01282486]-image!, P [P01282487]-image!, PMA! [PMA103270], US!).

Description.

Plants terrestrial (or epipetric?). Stems ascending to erect, stramineous, 3-5 cm long, 0.05-0.1 mm diam., non-articulate, flagelliform on branches, stoloniferous, 1- or 2-branched. Rhizophores axillary, borne on proximal ¼ of stems, filiform, 0.05 mm diam. Leaves heteromorphic throughout, membranaceous, both surfaces glabrous, upper surfaces green, lower surfaces silvery green. Lateral leaves spreading or slightly ascending, ovate to ovate-elliptic, 1.0-1.4 × 0.5-0.7 mm; bases rounded, acroscopic bases overlapping stems, basiscopic bases free from stems; acroscopic margins hyaline (more conspicuously so on lower surfaces), in a band 2-8 cells wide with the cells elongate, straight-walled and papillate parallel to margins, papillae in 1 or 2 rows over each cell lumen, long-ciliate throughout, basiscopic margins greenish or slightly hyaline in a band 1 or 2 cells wide with the cells rectangular, straight to sinuate-walled and papillate parallel to margins, papillae in 1-3 rows, long-ciliate throughout; apices cuspidate to short-acuminate, cusps 0.05 mm, variously tipped by 1-3 cilia; upper surfaces comprising quadrangular or rounded, sinuate-walled cells, many of these covered by 4-17 papillae, without idioblasts and with stomata along margins, lower surfaces comprising elongate, sinuate-walled cells, with few of these papillate and idioblast-like on both sides of the midribs, papillae in 2 rows over each cell lumen, with stomata in 2 rows along midribs. Median leaves distant, ascending, elliptic, 0.6-0.8 × 0.3-0.45 mm; bases rounded; margins hyaline in a band 2-6 cells wide, the cells elongate, straight-walled and papillate parallel to margins, papillae in 1 or 2 rows over each cell lumen, long-ciliate throughout; apices long-aristate, each arista 0.1-0.3 mm, denticulate distally on upper surfaces, tipped by 1 or 2 teeth; both surfaces without idioblasts, upper surfaces comprising quadrangular or rounded, sinuate-walled cells, many of these covered by 2-17 papillae, with stomata in 1 row along distal ¾ of the midribs and some along proximal ¼ of outer margins, lower surfaces comprising elongate, sinuate-walled cells, without stomata. Axillary leaves similar to lateral leaves. Strobili terminal on branch tips, quadrangular, 1.0-1.2 mm. Sporophylls monomorphic or the ventral ones slightly shorter, ascending, without a laminar flap, each with a slightly developed and glabrous keel along midribs, ovate to ovate-lanceolate, 0.7-1.2 × 0.5-0.8 mm; bases rounded; margins hyaline (this more obviously so on dorsal sporophylls), short-ciliate; apices acuminate to short-aristate, each acumen (arista) 0.05-0.1 mm, tipped by 1 or 2 teeth; dorsal sporophylls with upper surfaces green and cells as in median leaves, except for the half that overlaps the ventral sporophylls where the surfaces are hyaline with elongate, papillate, and slightly sinuate-walled cells, lower surfaces silvery green and comprising elongate, sinuate-walled cells; ventral sporophylls with both surfaces hyaline, comprising elongate, sinuate-walled cells. Megasporangia in 2 ventral rows; megaspores yellow, rugulate-reticulate on proximal faces with a slightly developed equatorial flange and perforate microstructure, reticulate on distal faces with echinulate and perforate microstructure (Fig. 6A-D ), 185-265 µm. Microsporangia in 2 dorsal rows; microspores orange, rugulate on proximal faces with echinulate microstructure, echinulate or baculate on distal faces with echinulate microstructure (Fig. 6E-I ), 24-30 µm.

Habitat and distribution.

Selaginella neospringiana is known only from the type collection made in Morro de Cubiçado, Petrópolis, Brazil. No information on the label exists as to its habitat, but in this region Campos de Altitude (highland fields or high-altitude fields) vegetation is common. The type collection was probably made at or around the peak of the Morro at ca. 1650 m and has some mosses associated with it; thus, Selaginella neospringiana may be terrestrial or epipetric.

Etymology.

The specific epithet honors Anton Friedrich Spring (1814-1872), a German physician and botanist who is the author of the only worldwide monograph of Selaginella . Spring described many species and proposed the first major classification of this ancient lycophyte genus. His contribution to our knowledge of Selaginella was significant. Therefore, it is fitting that this species collected at high elevations bears his name.

Conservation status.

As mentioned, Selaginella neospringiana is known only from the type collection made 135 years ago. It has apparently not been collected since, even though the area where it was gathered is visited by trekkers and adventurers. Taking this into account, this species is considered Endangered (En).

Discussion. Alston et al. (1981) cited the type of Selaginella neospringiana under Selaginella vestiens , but as pointed out by Valdespino et al. (2015) they are morphologically different and can be separated by the characters discussed under the diagnosis.

Figures

Figure 4. Selaginella neospringiana Valdespino. A Section of upper surface of stem B Upper surface of median leaf C Close-up of base and proximal portion of median leaf, upper surface D Close-up of distal portion and apex of median leaf, upper surface E Section of lower surface of stem F Lower surface of lateral leaf; note marginal stoma (a) G Close-up of proximal portion and base of lateral leaf, lower surface; note marginal stoma (a) on basiscopic margin and on outer margin of median leaf (far, lower right) H Close-up of distal portion and apex of lateral leaf, lower surface; note marginal stoma (a). A-H taken from the isotype, Glaziou 11723 (PMA).

Figure 5. Selaginella neospringiana Valdespino. A Lateral leaf and portions of median leaves, upper surfaces; note papillae on cells lumen and stomata (a) along midrib of median leaf B Close-up of upper surface of lateral leaf; note papillae on cells lumen. A-B taken from the isotype, Glaziou 11723 (PMA).

Figure 6. Selaginella neospringiana Valdespino. A Megaspore, proximal face B Close-up of megaspore, proximal face C Megaspore, distal face D Close-up of megaspore, distal face E Microspore, proximal face F Close-up of microspore, proximal face G Microspore, distal face H Close-up of microspore, distal face I Microspore, equatorial view. A-I taken from the isotype, Glaziou 11723 (PMA).