Seven new species of Selaginella subg. Stachygynandrum (Selaginellaceae) from Brazil and new synonyms for the genus

Abstract We describe seven new species of Selaginella subg. Stachygynandrum (Selaginella alstonii, Selaginella blepharodella, Selaginella crinita, Selaginella mucronata, Selaginella mucugensis, Selaginella saltuicola, and Selaginella sematophylla) from Brazil and discuss their possible affinities and conservation status. Scanning electron micrographs of stem sections, leaves, and spores are provided to illustrate the new taxa. In Selaginella alstonii and Selaginella saltuicola vegetative growth from strobilus tips is reported and discussed. Four of the new species are from the Espinhaço Mountain Range associated with Campos Rupestres (montane savannah/rocky fields) vegetation. Three of these (i.e., Selaginella blepharodella, Selaginella crinita, and Selaginella mucugensis) were collected in the northern part of the range in Chapada Diamantina, state of Bahia, while Selaginella alstonii is from the southern part of the range in the state of Minas Gerais. Selaginella mucronata is found in Atlantic Rainforest vegetation in the state of Espírito Santo, whereas Selaginella saltuicola inhabits Cerrado (tropical savannah) vegetation in the state of Mato Grosso. Selaginella sematophylla is the most widely distributed of the new species and was collected in Espírito Santo, Minas Gerais, and Rio de Janeiro states in Campos Rupestres and Atlantic Rainforest vegetation. Selaginella alstonii occurs in rocky caves, Selaginella blepharodella, Selaginella crinita, Selaginella mucugensis, and Selaginella sematophylla seem adapted to seasonally dry places, living on sandy or humid soils, Selaginella mucronata occupies humid, forest understory, and Selaginella saltuicola is adapted to wet places associated with rocks or logs in waterfalls. Of the seven new species, six are considered local endemics (except for Selaginella sematophylla) because of their restricted currently known distributions to one or two localities within a single state in Brazil. Additionally, we propose new synonymy for Selaginella palmiformis (syn. = Selaginella bahiensis subsp. manausensis, ≡ Selaginella manausensis) and Selaginella vestiens (syn. = Selaginella fragillima); the last species is endemic to Brazil, recorded in the states of Goiás and Minas Gerais. Finally, based on literature discussed and this study, we conclude that the number of well-documented Brazilian Selaginella species is 61, of which 58 are native and three introduced and naturalized. These statistics are likely to change with further work on Selaginella from Brazil.

currently known distributions to one or two localities within a single state in Brazil. Additionally, we propose new synonymy for S. palmiformis (syn. = S. bahiensis subsp. manausensis, ≡ S. manausensis) and S. vestiens (syn. = S. fragillima); the last species is endemic to Brazil, recorded in the states of Goiás and Minas Gerais. Finally, based on literature discussed and this study, we conclude that the number of welldocumented Brazilian Selaginella species is 61, of which 58 are native and three introduced and naturalized. Th ese statistics are likely to change with further work on Selaginella from Brazil.

Introduction
Th e genus Selaginella P. Beauv. (Selaginellaceae) is cosmopolitan and comprises 600-750 species mostly distributed in tropical and subtropical regions of the world, although some are adapted to live in dry, desert-like areas and some are circumboreal (Jermy 1990, Valdespino 1993a, Mickel et al. 2004. Alston et al. (1981) recorded 45 species and two subspecies of Selaginella from Brazil, while Hirai (2015) listed 56 taxa, including two subspecies and three introduced species. As part of ongoing work on Selaginella by the senior author and a study of this genus in the state of Minas Gerais conducted by Heringer (2011) under the supervision of Salino, we now describe seven new taxa from Brazil: S. alstonii G. Heringer, Salino & Valdespino, S. blepharodella Valdespino, S. crinita Valdespino, S. mucronata G. Heringer, Salino & Valdespino, S. mucugensis Valdespino, S. saltuicola Valdespino, and S. sematophylla Valdespino, G. Heringer & Salino, and place them in subg. Stachygynandrum (P. Beauv.) Baker following Jermy's (1986Jermy's ( , 1990 infrageneric classifi cation. Th ree of the new species Selaginella blepharodella, S. crinita, and S. mucugensis are reported from three localities (i.e., Pico das Almas in Serra do Rio de Contas and Ibicoara and Mucugê in Serra do Sincorá) of Chapada Diamantina in the state of Bahia, whereas S. alstonii was collected in Santo Antônio do Itambé in the state of Minas Gerais. Th ese localities are within the Espinhaço Mountain Range, which is dominated by "Campos Rupestres" (montane savannah/rocky fi elds) vegetation (Melo 2000, São-Pedro andFeio 2011) and recognized as an important biodiversity and endemism center (Harley and Simmons 1986, Melo 2000, Rapini et al. 2008, Bünger et al. 2014. Selaginella mucronata was collected in Castelo, Parque Estadual do Forno Grande, a locality that has highland remnants of the rich, biodiverse Atlantic Rainforest vegetation in the state of Espí rito Santo, southeastern Brazil (Meirelles andGoldenberg 2012, Silva-Soares andScherrer 2013). Selaginella saltuicola is recorded from Chapada dos Guimarães, a high plateau in the state of Mato Grosso (Oliveira-Filho and Martins 1991) in the Central-West region of Brazil, where the species-rich (Ratter et al. 1997) "Cerrado" (tropical savannah) vegetation is dominant (Oliveira-Filho and Martins 1991) and waterfalls, caves, and ponds are common. Finally, S. sematophylla seems to be the most widely distributed species of all the spike mosses newly described herein, as it is recorded from Campos Rupestres vegetation in the localities of São Sebastião do Paraíso and Parque Estadual de Serra Nova, part of the Espinhaço Mountain Range, in the state of Minas Gerais and in mountane areas with some remnants of Atlantic Rainforest vegetation such as Pedra do Garrafão in Santa Maria do Jetibá, state of Espírito Santo and Santo Antônio do Imbé in the state of Rio de Janeiro. Because of their restricted currently documented distributions to one or two localities within a single Brazilian state, six of these new species, except for S. sematophylla, are tentatively considered local endemics.

Material and methods
Herbarium specimens were examined from B, BHCB, BM, CAS, CESJ, COL, G, GH, INPA, K, MG, MO, NY, P, PMA, QCA, R, RB, UC, US, and W (Th iers 2015) and samples for Scanning Electron Microscopy (SEM) were taken from selected collections to document upper and lower surfaces of stems and leaves, as well as spore morphology. Although for each of the new species an eff ort was made to secure megaspore and microspore samples to determine sculpturing pattern, color, and diameter, these were not always available or, in some cases, were too immature to be utilized for those purposes. Th e SEM samples were prepared, viewed, and photographed at diff erent magnifi cations using a Zeiss Model Evo 40 at 20-30 KV following standard techniques as described by Valdespino (1995) and Valdespino et al. (2014). Digitized SEM images were post-processed with Adobe Photoshop and assembled according to species in multipart fi gures.
In heterophyllous species of Selaginella (i.e., subg. Stachygynandrum, where the new taxa are classifi ed, and subg. Heterostachys Baker) there are three kinds of vegetative leaves (i.e., lateral/ventral, median/dorsal, and axillary). Th e axillary leaves are located ventrally at branch forks on dorsiventral shoots and are usually morphologically similar to lateral leaves (Schoute 1938, Valdespino 1995 and, thus, in previous descriptions vegetative leaves are often referred to as "dimorphic". Nevertheless, on occasion, axillary leaves may be quite diff erent morphologically from lateral leaves (Valdespino 1995) and to take this into account we decided to use the term "heteromorphic" when describing vegetative leaves in our species descriptions. Likewise, sporophylls are described as "monomorphic" because no signifi cant diff erences in their size and form were found; however, their epidermal cell composition may be diff erent according to their plane of insertion on the strobilus axis with respect to the main stem, which allows two types to be recognized: "dorsal sporophylls" (inserted in the same plane as the median/dorsal leaves) and "ventral sporophylls" (inserted in the same plane as the lateral/ventral leaves). Otherwise, descriptions of the new species were made according to terminology utilized by Valdespino (1995), while leaf and spore measurement methods and the terminology used to describe leaf surfaces are those explained in Valdespino et al. (2014). Th e description of spore morphology follows Valdespino (1995), Punt et al. (2007), and Hesse et al. (2009). Description. Plants epipetric. Stems prostrate to ascending, greenish to stramineous, to 10 cm long, 0.3-0.6 mm diam., exarticulate, not fl agelliform or stoloniferous, 2-or 3-branched. Rhizophores ventral, borne on the proximal ⅔ of stems, fi liform, 0.1-0.2 mm diam. Leaves heteromorphic throughout, chartaceous, both surfaces glabrous, upper surfaces green, lower surfaces silvery green. Lateral leaves distant, spreading to slightly ascending, oblong to oblong-lanceolate, 1.1-2.0 × 0.4-1.0 mm; bases rounded, acroscopic bases overlapping stems, basiscopic bases free from stems; acroscopic margins on upper surfaces hyaline along proximal ½-¾ in a band 1 or 2 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, otherwise greenish distally with rounded to quadrangular, sinuate-walled cells, on lower surfaces hyaline in a band 2-5 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, short-ciliate along proximal ⅓-½, otherwise serrate distally, basiscopic margins greenish on upper surfaces with rounded to quadrangular, sinuate-walled cells and on lower surfaces with elongate, sinuate-walled cells, entire along proximal ¾ and serrulate on distal ¼; apices acute to slightly cuspidate, each cusp 0.02-0.03 mm, tipped by 1-3 teeth; upper surfaces comprising rounded to quadrangular, sinuate-walled cells, without idioblasts or stomata, lower surfaces comprising elongate, sinuate-walled cells, with some obscure, papillate idioblasts and stomata along central portion of midribs and along basiscopic margins. Median leaves distant to slightly imbricate near the branch tips, ascending, elliptic to elliptic-lanceolate or ovate-elliptic, 0.7-1.4 × 0.4-0.7 mm; bases oblique; margins hyaline in a band 2-5 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, inner margins serrate to short-ciliate, outer margins entire along proximal ½, otherwise serrate to short-ciliate distally; apices acuminate to short-aristate, each acumen (arista) 0.15-0.2 mm, entire or obscurely tipped by 1-3 teeth; both surfaces without conspicuous idioblasts, upper surfaces comprising quadrangular to rounded, sinuate-walled cells, some of these covered by 10-20 papillae, with stomata along midribs on distal half and submarginal and marginal along proximal half of outer margins, lower surfaces comprising elongate, sinuate-walled cells, without stomata. Axillary leaves similar to lateral leaves but with both margins ciliate along proximal ¼, otherwise short-ciliate to serrate distally. Strobili terminal on branch tips, compact, quadrangular, 1.5-4.0 mm. Sporophylls monomorphic, without a laminar fl ap, ovate to ovate-lanceolate, 0.7-1.1 × 0.4-0.6 mm, each with a dentate (teeth often caducous) keel along distal ½ of the midribs; bases rounded; margins narrowly hyaline, serrate; apices acute, entire or obscurely tipped by 1-3 teeth; dorsal sporophylls with upper surfaces green and cells as in median leaves, except for the half that overlaps the ventral sporophylls, there hyaline with elongate, sinuate-walled cells, lower surfaces silvery green and comprising elongate, sinuate-walled cells; ventral sporophylls with both surfaces hyaline to faintly greenish hyaline, comprising elongate, sinuate-walled cells. Megasporangia in proximal portion in 2 ventral rows; megaspores cream, with a cristate equatorial fl ange, rugulate on proximal faces, reticulate with low, cristate ridges on distal faces, with areolate-perforate microstructure on both faces, 250-300 μm diam. Microsporangia in 2 dorsal rows and, in distal portion, also in 2 ventral rows; microspores orange, psilate marginally and verrucate-rugulate towards the center with psilate microstructure on proximal faces, clavate (Fig. 2G, H) or echinulate to baculate (if apices of projected elements broken off , Fig. 2F, H) with striate to striate-reticulate microstructure on distal faces, 27-33 μm diam. Habitat and distribution. Selaginella alstonii is epipetric on rocky caves in Campos Rupestres vegetation; the type and paratype were collected at an elevation range of 1676-1810 m. Th e species is known only from Parque Estadual do Pico do Itambé in Serra do Espinhaço, Minas Gerais, Brazil, where it may be a local endemic.
Etymology. Selaginella alstonii is named for Arthur Hugh Garfi t Alston (1902Alston ( -1958, a British pteridologist and one of the world's authorities on the genus Selaginella. Conservation status. Th ere is limited information on the conservation status and range distribution of Selaginella alstonii. Nevertheless, given that the localities where this species is presently known are located within the Espinhaço Mountain Range, a habitat threatened by human activities (Rapini et al 2008), we tentatively consider it vulnerable (VU) according to IUCN (2012) categories and criteria.
Discussion. Selaginella alstonii belongs to subg. Stachygynandrum and is characterized by its oblong to oblong-lanceolate lateral leaves with acroscopic margins shortciliate along proximal ⅓-½ and elliptic to elliptic-lanceolate or ovate-elliptic median leaves with oblique bases (Fig. 1). Dried specimens of S. alstonii tend to develop a groove along midribs of lateral leaves (Fig. 1A), but it remains to be confi rmed if this is a character observed in living plants or an artifact when plants are dried. Th e surfaces of the median and lateral leaves of S. alstonii do not show conspicuous idioblasts when observed with a stereoscope, but on SEM micrographs, idioblast-like, papillate elongate cells are observed on the lower surfaces of lateral leaves, with papillae in 1 row over each cell lumen, parallel to the midribs (Fig. 1D). Additionally, in some median leaves, the outer bases have 2-4 short cilia. In some plants of S. alstonii, as well as in S. saltuicola (which see for discussion), we observed vegetative growth from the tips of some strobili.
Selaginella alstonii resembles S. acanthostachys from Colombia, Ecuador, and Peru; however the characters given in the diagnosis separate them. Among other species of Selaginella from Minas Gerais, S. alstonii may be confused with S. decomposita Spring because of their similar texture and shape of the lateral leaves. Selaginella decomposita, however, has an ascending to erect habit and is a more robust plant. Diagnosis. Selaginella blepharodella diff ers from similar S. thysanophylla A.R. Sm. in its short-(vs. non-) stoloniferous stems, median leaves broadly-ovate to ovate-elliptic (vs. ovate or orbicular), 0.6-1.0 × 0.4-0.6 (vs. 1.4 × 1.0) mm, with stomata on upper surfaces restricted to the midribs (vs. also on submarginal and marginal regions on proximal ¼ near outer bases), lateral leaves broadly ovate to ovate-oblong (vs. ovate or orbicular), 0.8-2.0 × 0.5-0.8 (vs. 2.0 × 1.5) mm, and upper surfaces of sporophylls with long or short cilia along distal ½ of the midribs (vs. upper surfaces glabrous).
Description. Plants terrestrial or epipetric. Stems decumbent to suberect, stramineous, 1.5-9.5 cm long, 0.3-0.4 mm diam., exarticulate, not fl agelliform, short-stoloniferous, 1-or 2-branched. Rhizophores axillary or axillary-ventral, restricted to bases of stems, fi liform, 0.1-0.2 mm diam. Leaves heteromorphic throughout, chartaceous, those on and above fi rst branch of stems with both surfaces usually glabrous and those below the fi rst branch of stems often with few, caducous cilia-like or dentate projections on the upper surfaces of the median leaves and sporophylls and on the lower surfaces of lateral leaves, upper surfaces green or brownish (when old), lower surfaces silvery green or shiny brown (when old). Lateral leaves imbricate, spreading or ascending, broadly ovate to ovate-oblong, 0.8-2.0 × 0.5-0.8 mm; bases rounded to subcordate, acroscopic bases overlapping stems (more so on leaves below fi rst branch), basiscopic bases free from stems; acroscopic margins broadly hyaline, especially along proximal ⅓ in a band 3-15 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 or 2 rows over each cell lumen, long-ciliate along proximal ⅔ and short-ciliate to serrate along distal ⅓, basiscopic margins hyaline to greenish hyaline in a band 4-6 cells wide, the cells as on acroscopic margins, ciliate throughout or sometimes cilia absent from proximal ¼-⅓; apices acute, tipped by 1-4 teeth or 2 or 3 cilia, especially on leaves below fi rst branch; upper surfaces comprising quadrangular to rounded, sinuatewalled cells covered by 5-15 papillae, without idioblasts or stomata, lower surfaces comprising elongate, sinuate-walled cells, most of these papillate and idioblast-like, papillae in 1 or 2(-3) rows over each cell lumen, with stomata in 2 or 3(-4) rows along midribs and some along proximal ¼ of basiscopic margins. Median leaves imbricate, ascending, broadly-ovate to ovate-elliptic, 0.6-1.0 × 0.4-0.6 mm; bases oblique, inner bases truncate, outer bases rounded and glabrous or these may also be ventricose (i.e., swollen) and each with a tuft of long cilia on leaves below fi rst branch; margins broadly hyaline, especially the inner ones, in a band 5-15 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 or 2 rows over each cell lumen, long-ciliate throughout or infrequently along only distal ⅘; apices gradually tapering into a long acumen, each acumen 0.1-0.3 mm, tipped by 2 or 3 cilia; both surfaces without idioblasts, upper surfaces comprising quadrangular to rounded, sinuate-walled cells covered by 5-15 papillae, with stomata along midribs, lower surfaces comprising elongate, sinuate-walled cells, without stomata. Axillary leaves similar to lateral leaves. Strobili terminal on branch tips, compact, quadrangular, 1.2-9.0 mm long. Sporophylls monomorphic, without a laminar fl ap, ovate, 0.6-0.9 × 0.4-0.7 mm, each with a ciliate keel along distal ½ of the midribs; bases rounded; margins hyaline, long-ciliate; apices acute, tipped by 1 or 2 cilia; dorsal sporophylls with upper surfaces green and cells as in median leaves, except for the half that overlaps the ventral sporophylls, there hyaline with elongate, papillate, and slightly sinuate-walled cells, lower surfaces silvery green and comprising elongate, sinuate-walled cells (Fig. 4F); ventral sporophylls with both   surfaces hyaline to greenish, comprising elongate, sinuate-walled cells. Megasporangia in proximal portion in 2 ventral rows; megaspores light-yellow, rugulate-reticulate on proximal faces, reticulate on distal faces, with psilate-perforate microstructure on both faces, 200-230 μm diam. Microsporangia in 2 dorsal rows and, in distal portion, also in 2 ventral rows; microspores orange, verrucate-rugulate with granulate microstructure on proximal faces, broadly capitate to clavate (5B-D) or broadly baculate (if apices of projected elements broken off , Fig. 5G, H) with reticulate-perforate and echinulate microstructure on distal faces, ca. 30-38 μm diam.
Habitat and distribution. Selaginella blepharodella is presumed to be a local endemic of the Serra do Sincorá , Espinhaç o Range, state of Bahia, Brazil, where it is known from only two localities, growing on sandy soil or overhanging from rocks at 1400 m.
Etymology. Th e epithet of the new species derives from the Greek blepharis, meaning eyelash, ode meaning similar to and ella, Latin diminutive suffi x; this refers to the long-ciliate leaf margins that resemble miniature eyelashes.
Conservation status. Selaginella blepharodella is known from only two collections in Serra do Sincorá and may be expected to occur in places with similar vegetation types in the Chapada Diamantina region of the Espinhaço Mountain Range. Th e Chapada Diamantina region and the Espinhaço Mountain Range, in general, are still subject to anthropomorphic pressure, including low-scale mining (Pedreira 2002), subsistence agriculture accompanied by the slash-and-burn methods, and plant extraction for commerce (Rapini et al. 2008). Based on these threats and according to IUCN (2012) categories and criteria, this species is tentatively considered vulnerable (VU).
Discussion. Selaginella blepharodella is a member of subg. Stachygynandrum and is defi ned here in a broad sense to encompass the morphological variability found within the two collections examined. In general, this species is characterized by long-ciliate leaves with broadly hyaline margins, lateral leaves imbricate, spreading to ascending with lower surfaces almost completely comprising elongate, papillate, sinuate-walled cells with papillae in 1-3 rows over cell lumina and stomata in 2 or 3(-4) rows along midribs amidst shortly elongate, sinuate-walled cells, and median leaves with apices ending in 2 or 3 cilia (Figs 3, 4). Th e type collection (Moraes & van der Werff 2933) has stems more than 3 cm tall, is 2-or 3-brached, and has lateral leaves mostly spreading to ascending and imbricate at branch tips (Fig. 3), whereas the paratype (Ule 7298) is a much smaller plant to 3 cm tall, is 1-or 2-branched, and has lateral leaves imbricate throughout (Fig. 4). In both specimens, the leaves below the fi rst branch tend to be more imbricate, have wider hyaline margins and longer marginal cilia, and the outer bases of the median leaves may be ventricose and with a tuft of long cilia (Fig. 4E). Additionally, below the fi rst branch, they may have scarce and caducous cilia-like projections on the upper surfaces of the median leaves and sporophylls (Fig. 4E, F) and on the lower surfaces of lateral leaves. In these characters, Selaginella blepharodella, especially the paratype, is similar and perhaps related to S. thysanophylla from Venezuela ( Fig. 4G). Th ese two species also share similar megaspore color; however Selaginella blepharodella can be separated from S. thysanophylla by the characters discussed in the diagnosis. Selaginella blepharodella diff ers further from S. thysanophylla by having megaspores 200-230 (vs. 150-200) μm, lateral leaves with acute (vs. rounded to subacute) apices, median leaves with the inner margins hyaline in a band 5-15 (vs. 20-25) cells wide at least along proximal ⅓ with long-acuminate (vs. apiculate) apices, each acumen 0.1-0.3 (vs. acumen 0.05-0.1) mm, and sporophyll apices each tipped by 2 cilia (Fig. 4F) [vs. 2 teeth; (Fig. 4H)].
In Brazil, Selaginella blepharodella does not seem to have close relatives, but it shares some characters, e.g., hyaline and ciliate leaf margins, with the newly described S. mucugensis and S. crinita (which see for comparison). Diagnosis. Selaginella crinita is morphologically similar to and may be confused with the Brazilian endemic, S. jungermannioides (Gaudich.) Spring, but diff ers in its lateral leaves long-ciliate throughout the basiscopic margins (vs. along proximal ¼ and then serrulate distally), median leaves with margins long-ciliate throughout (vs. along proximal ¼, particularly on outer margins, otherwise short-ciliate to serrulate distally), and apices long-acuminate (vs. cuspidate to acuminate) with each acumen hyaline (vs. cusp or acumen green) tipped by 2-4 long cilia (vs. entire).
Habitat and distribution. Selaginella crinita is known only from the type collection from Pico das Almas, Serra do Rio de Contas, Bahia, Brazil, where it is probably a local endemic. It grows on shady rocky and sandy soil at 1100-1300 m.
Etymology. Th e specifi c epithet is derived from the Latin crinitus, meaning long haired; this refers to the many, long cilia along leaf margins.
Conservation status. Th ere is insuffi cient data to defi nitively ascertain distributional range, abundance, and possible threats to this species. Nevertheless, since its type locality is in the Chapada Diamantina region of the Espinhaço Mountain Range, which is threatened by anthropomorphic activities (Rapini et al. 2008), Selaginella crinita is tentatively considered vulnerable (VU), according to IUCN (2012) categories and criteria.
Discussion. Selaginella crinita is a prostrate species that belongs to subg. Stachygynandrum and is characterized by its median leaves ovate-lanceolate to ovate-elliptic, with the inner and the outer margins symmetric, and apices tapering into a long-acumen with each acumen tipped by 2-5 cilia, lateral leaves ovate-elliptic to ovate-oblong, as well as longciliate leaf margins, and quadrangular to rounded sinuate-walled cells on upper surfaces of median and lateral leaves covered by many (15-30) papillae. Because of its imbricate and long-ciliate lateral leaves and leaves tipped by cilia, Selaginella crinita may be confused with S. blepharodella. Selaginella crinita is easily separated from S. blepharodella by its prostrate (vs. decumbent to suberect) habit, median leaves margins hyaline in a band 2-5 (vs. 5-15) cells wide, lateral leaves with obtuse to rounded (vs. acute) apices, and the cells of upper surfaces of median and lateral leaves covered by 15-30 (vs. 5-15) papillae.
Selaginella crinita belongs to a Neotropical group of Selaginella species, here informally termed the "Selaginella jungermannioides group", characterized mostly by creeping or prostrate habit, rhizophores usually distributed throughout the stems, median leaf apices acute, cuspidate, acuminate, or aristate, and lateral leaves often ovate-oblong or oblong with truncate, obtuse to broadly acute apices. Th e "Selaginella jungermannioides group" tentatively includes the South American taxa S. applanata A. Braun (Colombia, Venezuela, and Peru), S. homaliae A. Braun (Colombia and Brazil), S. jungermannioides (Brazil), S. schultesii Alston ex Crabbe & Jermy (Colombia), and S. truncata H. Karst. ex A. Braun (Colombia, Peru, and Bolivia), as well as S. lindenii Spring from southern Mexico. Among species in the "Selaginella jungermannioides group", S. crinita is morphologically close to S. applanata, S. jungermannioides, and S. lindenii. Selaginella crinita can be separated from S. applanata by its median leaves with inner and outer margins symmetric (vs. inner margins straight and outer margins convex), long-acuminate (vs. long-aristate) apices tipped by cilia (vs. entire), and acroscopic margins of lateral leaves ciliate throughout (vs. along proximal ½). It can be easily distinguished from S. lindenii by the upper surfaces of lateral and axillary leaves glabrous (vs. hispid), whereas from S. jungermannioides it diff ers by the characters of marginal projections of leaves and form of the median leaf apices, as discussed in the diagnosis. Additionally, Selaginella crinita may be confused with S. homaliae and S. truncata, but it is set apart from them by its median leaf apices long-acuminate (vs. acute to short-cuspidate) and margins long-ciliate throughout (vs. dentate to serrate in S. homaliae and in S. truncata inner margins denticulate and outer margins sparingly long-ciliate along proximal ⅓, otherwise denticulate). Selaginella crinita also diff ers from the newly described S. mucronata, which may be part of the "Selaginella jungermannioides group", by its median leaves ovate-lanceolate to ovate-elliptic (vs. orbiculate to broadly elliptic), with stomata on upper surfaces along midribs (vs. distributed throughout the leaf laminae), and apices long-acuminate (vs. mucronate or infrequently acute), as well as by having the cells on the upper surfaces of the lateral and median leaves covered by 15-30 (vs. 5-10) papillae.
Habitat and distribution. Selaginella mucronata is known only from the type collection from Parque Estadual do Forno Grande, state of Espí rito Santo, growing on rocks in understory of Atlantic Rainforest vegetation at 1200 m. It could be considered a local endemic given its limited distribution and the vegetational type.
Etymology. Th e epithet mucronata refers to the apices of the median leaves. Conservation status. Th e paucity of data available does not allow an assessment of abundance and possible threats to this species and, thus, we assign to it a Data Deficient (DD) conservation assessment according to IUCN (2012) categories and criteria.
Discussion. Selaginella mucronata belongs to subg. Stachygynandrum and is characterized by its creeping habit, orbicular to broadly elliptic, long-ciliate, mucronate or infrequently acute median leaves with stomata distributed throughout the upper surfaces ( Fig. 8A-C). Selaginella mucronata seems to be morphologically most similar to S. jungermannioides; however, the characters of leaf texture, margin type, and shape of median leaf bases discussed in the diagnosis distinguish these two species. Selaginella mucronata could be confused with S. crinita, another member of the "Selaginella jungermannioides group," which see for discussion.
Th e upper surfaces of Selaginella mucronata may be slightly corrugate (Fig. 8A-C), perhaps as a drying artifact, and because of this and its creeping habit it could be confused, among other Brazilian species, with S. fl exuosa Spring and S. macrostachya (Spring) Spring. Selaginella mucronata diff ers chiefl y from those two species in having the apices of median leaves mucronate or acute (vs. long-aristate) with each acumen 1 / 10 -1 / 16 (vs. arista ¼-¾) the length of the leaf lamina. Additionally, S. mucronata dif-  fers from S. fl exuosa by acroscopic margins of lateral leaves long-ciliate along proximal ½-2 / 3 and serrulate to entire distally (vs. denticulate along proximal ¼-½, otherwise entire distally) and the margins of the median and axillary leaves ciliate (vs. serrulate). It is further distinguished from S. macrostachya by its orbiculate to broadly elliptic (vs. cordate) median leaves with the outer bases glabrous (vs. tufted with short hairs) and lateral leaves with upper surfaces near basiscopic margins glabrous (vs. often with short, tooth-like hairs). Description. Plants terrestrial. Stems ascending to suberect, stramineous, 3-7 cm long, 0.2-0.4 mm diam., exarticulate, not fl agelliform, probably shortly stoloniferous, 2-or 3-branched. Rhizophores axillary and axillary-dorsal, restricted to the bases of stems, fi liform, 0.1-0.2 mm diam. Leaves heteromorphic throughout, chartaceous, both surfaces glabrous, upper surfaces green, lower surfaces silvery green or brownish (when old). Lateral leaves distant, slightly ascending, ovate to slightly ovate-oblong, 1.2-1.5 × 0.9-1.1 mm; bases rounded, acroscopic bases slightly to strongly overlapping stems, basiscopic bases free from stems; acroscopic margins hyaline in a band 2-8 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, long-to short-ciliate along proximal ¾ and serrate to entire along distal ¼; basiscopic margins narrowly hyaline or greenish in a band 1 or 2 cells wide, the cells as along acroscopic margins, entire along proximal ¼-½ and serrate to shortciliate distally, apices acute, tipped by 1-3 teeth; upper surfaces comprising rounded to quadrangular, sinuate-walled cells, some of these covered by 4-8 papillae, without idioblasts or stomata, lower surfaces comprising elongate, sinuate-walled cells, some of these papillate and idioblast-like, papillae in 2 rows over each cell lumen, with stomata in 2 or 3 rows along midribs and along proximal ½ of basiscopic margins. Median leaves distant, ascending, ovate, 0.8-1.3 × 0.5-0.7 mm; bases oblique, inner bases plane in profi le, outer bases ventricose (i.e., swollen); margins hyaline in a band 2-5 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, shortly ciliate throughout; apices acute to short-acuminate, each acumen 0.02-0.08 mm, occasionally with 1 or 2 hairs on upper surfaces, tipped by 1-3 teeth; both surfaces without idioblasts, upper surfaces comprising rounded to quadrangular, sinuate-walled cells covered by 4-8 papillae, with stomata along midribs and some on submarginal and marginal regions of the outer bases, lower surfaces comprising elongate, sinuate-walled cells, without stomata. Axillary leaves similar to lateral  leaves. Strobili terminal on branch tips, compact, quadrangular, 2.0-7.0 mm. Sporophylls monomorphic, without a laminar fl ap, ovate, 0.8-1 × 0.4-0.5 mm, each with a well-developed, frequently puberulous keel along the midribs; bases rounded; margins hyaline, short-ciliate to serrate; apices acute, 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, there hyaline with elongate, papillate, and slightly sinuatewalled cells, lower surfaces silvery green and comprising elongate, sinuate-walled cells; ventral sporophylls with both surfaces hyaline, comprising elongate, sinuate-walled cells. Megasporangia frequently proximal in 2 ventral rows or the proximal megasporangia abortive and a few intermixed with microsporangia; megaspores lemon-yellow, mostly immature or absent, proximal faces not observed, reticulate on distal faces, 275-285 μm. Microsporangia in 2 dorsal rows and, in distal portion, also in 2 ventral rows; microspores orange, gemmate-rugulate or broadly baculate-rugulate with psilate to echinulate microstructure on proximal faces, vermiculate with echinulate microstructure on distal faces, 30-40 μm.

Selaginella mucugensis
Habitat and distribution. Selaginella mucugensis is known only from the type collection from Mucugê, Serra do Sincorá, in the Chapada Diamantina region of the Espinhaço Mountain Range, where it is probably a local endemic. It grows terrestrially on damp soil in Campos Rupestres vegetation at ca. 984 m.

Etymology.
Th is species is named for the type locality. Conservation status. At present, there is limited information available to allow a conclusive determination of the conservation status of Selaginella mucugensis. Nevertheless, according to IUCN (2012) categories and criteria, we tentatively considered this species to be vulnerable (VU) on account that it is so far known from a single locality in the Espinhaço Mountain Range, which is threatened by human activities (Rapini et al. 2008).
Discussion. Selaginella mucugensis is a member of subg. Stachygynandrum and may be confused with S. blepharodella because they have similar leaf margins and indument on the upper surfaces in the distal region of median leaves and sporophylls (Fig.  7B). In fact, these two species may prove to be sympatric in the Serra do Sincorá, where both were collected. According to Harley and Simmons (1986), this area is an important center of diversity of the Brazilian montane fl ora. Selaginella mucugensis is distinguished from S. blepharodella by the characters discussed under the diagnosis.
Type Description. Plants epipetric or epiphytic. Stems creeping, stramineous to green, 1.5-3 cm long, 0.05-0.2 mm diam., exarticulate, not fl agelliform or stoloniferous, 1-branched. Rhizophores axillary, borne throughout stems, fi liform, 0.05-0.1 mm diam. Leaves heteromorphic throughout, thin-membranaceous, both surfaces glabrous, upper surfaces green, lower surfaces silvery green. Lateral leaves distant or imbricate apically, patent to slightly ascending, ovate, ovate-elliptic or ovate-oblong, 0.9-1.5 × 0.5-0.8 mm; bases rounded, acroscopic bases slightly to strongly overlapping the stems, basiscopic bases free from the stems; acroscopic margins on upper surfaces greenish or narrowly hyaline, if the latter, in a band 1 or 2 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, on lower surfaces hyaline in a band 2-4 cells wide, the cells as on upper surfaces, entire or minutely serrulate along distal ¼, basiscopic margins on upper surfaces greenish on lower surfaces, narrowly hyaline marginally in a band 2-4 cells wide, the cells as along acroscopic hyaline margins, entire or inconspicuously denticulate throughout; apices rounded to broadly acute, entire or tipped by 1-3 teeth; upper surfaces comprising rounded to quadrangular, sinuate-walled cells, some of these on or near basiscopic and apical regions of the laminae covered by 2-4 papillae, without idioblasts and with stomata along margins, lower surfaces comprising elongate, sinuate-walled cells, some of these papillate and idioblast-like, papillae in 1 row over each cell lumen, with stomata irregularly distributed along midribs, as well as on acroscopic half of the laminae and on both margins (visible in both surfaces of the laminae). Median leaves distant or imbricate apically, ascending to spreading, ovate or ovate-elliptic, 0.6-0.9 × 0.4-0.5 mm; bases rounded or oblique, ventricose (i.e., swollen); margins narrowly hyaline in a band 1-3 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, entire; apices acute, entire (not distinctly tipped by teeth or cilia); both surfaces without idioblasts, upper surfaces comprising rounded to quadrangular, sinuate-walled cells, many of these covered by 2-4 papillae, with stomata throughout the laminae and some near submarginal region of the outer bases, lower surfaces comprising elongate, sinuate-walled cells, without stomata. Axillary leaves similar to lateral leaves. Strobili borne throughout the stems, weakly defi ned, lax, fl attened, 1.0-2.0 mm. Sporophylls similar to or slightly diff erentiated from vegetative leaves, monomorphic to subdimorphic, without a laminar fl ap, ovate, 0.7-1.4 × 0.5-0.8 mm, each without a keel; bases rounded; margins narrowly hyaline, entire; apices acute, entire (not distinctly tipped by teeth or cilia); dorsal sporophylls with upper surfaces green and cells as in median leaves, except for the half that overlaps the ventral sporophylls, there hyaline to greenish 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 to greenish hyaline, comprising elongate, sinuate-walled cells. Megasporangia few in 1 ventral row; megaspores light-orange, mostly absent, proximal and distal faces not observed, not measured. Microsporangia in 2 dorsal rows and in 1 ventral row or few and in axils of median leaves; microspores deep orange, areolate-fossulate with granulate microstructure on proximal and distal faces, 25-31 μm.
Habitat and distribution. Selaginella saltuicola is unique among other species here described by its apparent adaptation to very wet areas near waterfalls and perhaps even partially submerged in water along creek banks in Cerrado vegetation. At present, this species is known only from the high plateau of the Chapada dos Guimarães, Mato Grosso, Brazil, where it may be a local endemic, growing on wet rocks or wet logs at 600-720 m.
Etymology. Th e epithet of the new species is derived from the Latin saltus, meaning jump, drop or fall and cola, meaning dweller, inhabitant, and alludes to it habitat near "cachoeiras" (waterfalls).
Conservation status. Selaginella saltuicola seems to be restricted to the Chapada dos Guimarães area, where the Cerrado vegetation is dominant and severely threatened by human activities (Oliveira-Filho and Martins 1991, Ratter et al. 1997, Strüssmann and Mott 2009. Selaginella saltuicola may therefore be tentatively considered vulnerable (VU), according to IUCN (2012) categories and criteria, at least until additional distributional and conservation status studies can be carried out.
Discussion. Selaginella saltuicola belongs to subg. Stachygynandrum and is morphologically similar to S. prasina from Cuba, S. salazariae Valdespino from Panama, and S. undata Shelton & Caluff , from Cuba, because they share similar habit and overall vegetative leaf morphology, stomata throughout upper surfaces of median leaves, and midribs of lateral leaves restricted to ca. ¼ below apices. However, S. undata (isotype: Shelton & Caluff 4514, B!) falls within the morphological range of S. prasina and may be best considered conspecifi c with the latter. Selaginella saltuicola diff ers from S. prasina by the characters of median leaf shape, apex type, inner margin color and projections, leaf base shape, strobilus morphology, and megaspore color, as discussed in the diagnosis, as well as by having ovate, ovate-elliptic, or ovate-oblong (vs. obovate) axillary leaves and many cells on the upper surfaces of median leaves covered by 2-4 ( Fig. 12B) [vs. without (Fig. 12E)] papillae. It diff ers from Selaginella salazariae in its median leaves ovate or ovate-elliptic (vs. obovate, obovate-elliptic, or broadly elliptic) with acute (vs. abruptly cuspidate to short-aristate) apices.
We note that Neotropical Selaginella species studied (i.e., S. prasina, S. salazariae, and S. saltuicola) that grow either partially underwater or constantly wetted by waterfalls, rivers, or creeks have numerous stomata distributed over the upper surfaces of median leaves (Fig. 12A, B, E) and broadly acute to obtuse, rounded (Fig. 12A, C, D) or truncate lateral leaves (Fig. 12F). At present, it is not clear if the shared characters among those species might be the result of adaptation to a similar habitat (i.e., wet rocks or logs on waterfalls or stream banks) by convergent evolution or synapomorphies that may phylogenetically relate them.
In some plants of Selaginella saltuicola, as well as in some of S. alstonii, we found strobili with continuous, vegetative growth from their apices. Th is condition was reported to occur in the genus by Hieronymus (1901), Williams (1931), Jermy (1990), and Valdespino (1993aValdespino ( , 1993bValdespino ( , 1995. In Selaginella, normally, fertile shoots (strobili) originate from the tips of vegetative shoots (i.e., stems and branches) in a "vegetative (V)/determinate fertile (F) growth pattern" or "V/F pattern," although in plants of some species, e.g., S. decomposita and S. saltuicola, microsporangial development was observed in axils of median leaves, similarly to what is seen in S. denticulata (L.) Spring where mega-and microsporangia are found in axils of lateral leaves below the weekly diff erentiated strobilus (see images in Quiles 2015). In the phenomenon described for S. saltuicola and S. alstonii, however, the fertile growth becomes indeterminate and the apices of strobili revert to a vegetative condition in what could be termed a "V/ indeterminate F/V growth pattern" or "V/F/V pattern" that is also found in other   Zhang et al. (2014) termed TST (where T is for trophophyll = vegetative leaf, and S is for sporophyll) arrangement of microphylls. In a third condition, the second vegetative growth of the V/F/V pattern of the shoot becomes fertile and indeterminate in a "V/F/ V/indeterminate F growth pattern" or "V/F/V/F" pattern, found for example in Selaginella correae Valdespino from Panama (Valdespino 1993b), S. oregana D.C. Eaton from temperate zones in western North America (Valdespino 1993a), and S. tuberculata Spruce ex Baker (e.g., Steyermark 75483, NY!) from South America. Th is V/F/V/F pattern consists of a shoot with alternating vegetative leaves, sporophylls, and vegetative leaves along the stems and is reminiscent of the pattern found in some species of Huperzia (Lycopodiaceae). Valdespino (1995) suggested these alternating patterns of vegetative stems and fertile shoot formation could be an adaptive strategy of Selaginella, or it could be a response to damage to the growing apices. In any case, hormones may probably mediate this phenomenon, which seems to be more common and found across geographically and phylogenetically diff erent Selaginella taxa than previously acknowledged. Th e ecological advantages of such variation, phylogenetic signifi cance, and possible genetic and/or hormonal origin remain to be determined. Description. Plants terrestrial. Stems creeping, stramineous, 2-3.5 cm long, 0.1-0.3 mm diam., exarticulate, not fl agelliform or stoloniferous, 1-branched. Rhizophores axillary, borne throughout stems, fi liform, 0.05-0.1 mm diam. Leaves heteromorphic throughout, thin-membranaceous to chartaceous, both surfaces glabrous, upper surfaces green, lower surfaces silvery green. Lateral leaves distant or imbricate distally, patent, ovate, 1.0-1.4 × 0.6-0.9 mm; bases rounded, acroscopic bases strongly overlapping the stems, basiscopic bases free from the stems; acroscopic margins hyaline to green-hyaline in a band 2-6 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, short-to long-ciliate along proximal ¼-½ and serrulate distally; basiscopic margins hyaline in a band 2 or 3 cells wide, the cells as on acroscopic margins, short-ciliate along proximal ⅕, otherwise serrate to serrulate along distal ⅘; apices acute, tipped by 1-3 teeth; upper surfaces comprising quadrangular to rounded, sinuate-walled cells, some of these on or near basiscopic and apical regions of the laminae, which are covered by 1-5 papillae, without idioblasts or stomata, lower surfaces comprising elongate, sinuatewalled cells, some of these papillate and idioblast-like, papillae in 1 row over each cell lumen, with stomata along midribs and few irregularly distributed over laminae. Median leaves imbricate, ascending, lanceolate, 0.8-1.4 × 0.3-0.7 mm; bases oblique to rounded, margins hyaline in a band 3-7 cells wide, the cells elongate and papillate parallel to margins, papillae in 1 row over each cell lumen, serrate to denticulate throughout; apices acute, tipped by 1 or 2 teeth; upper surfaces comprising rounded to quadrangular, sinuate-walled cells, most of these covered by 1-7 papillae, and some idioblast-like, papillate, elongate cells with papillae in 1 row over each cell lumen along both sides of the midribs, with stomata in 1 or 2 rows along midribs and a few irregularly distributed on proximal region of inner half of the laminae, lower surfaces comprising elongate, sinuate-walled cells, without stomata. Axillary leaves similar to lateral leaves. Strobili terminal on branch tips, lax, slightly quadrangular, 2.0-8.0 mm. Sporophylls monomorphic to slightly dimorphic, without a laminar fl ap, lanceolate, 1-1.4 × 0.5-0.8 mm, each without a keel; bases rounded; margins hyaline, serrulate; apices gradually acute, tipped by 1-3 teeth; dorsal sporophylls with both surfaces having idioblasts, upper surfaces green with cells as in median leaves, except for the half that overlaps the ventral sporophylls, there hyaline to greenish hyaline and with elongate, papillate, and slightly sinuate-walled cells, lower surface silvery green comprising elongate, sinuate-walled cells; ventral sporophylls with both surfaces hyaline and comprising elongate, sinuate-walled cells. Megasporangia in 2 ventral rows; megaspores cream or light-yellow, rugulate-reticulate with granulateperforate microstructure on proximal faces, reticulate or reticulate-granular with granulate-echinulate and perforate microstructure on distal faces, 275-290 μm. Microsporangia in 2 dorsal rows; microspores orange, psilate marginally to rugulate towards the center with granulate microstructure on proximal faces, rugulate-cristate or cristate with broad baculate-like projections and granulate microstructure on distal faces, 28-40 μm.

Selaginella sematophylla
Habitat and distribution. Selaginella sematophylla is known from Minas Gerais, Espírito Santo, and Rio de Janeiro states in Brazil. It grows in Campos Rupestres and Atlantic Rainforest vegetation on sandy soil in shaded, wet places at 1000-1230 m. Etymology. Th e epithet of the new species derives from the Greek, sema -tos, meaning sign, fl ag, mark and phyllon, meaning leaf; this refers to the presence of conspicuous, hyaline idioblasts on upper leaf surfaces.
Conservation status. Th e distributional range of Selaginella sematophylla encompasses three southeastern states of Brazil, but the vegetation types it inhabits are in peril; thus, we believe advisable to consider it vulnerable (VU), according to IUCN (2012) categories and criteria.
Additional specimens examined ( Discussion. Selaginella sematophylla is a member of subg. Stachygynandrum and is characterized by having stems 1-branched, lateral and median leaves with hyaline margins, and idioblasts on upper surfaces of median leaves (Fig. 14A, B), lower surface of lateral leaves (Fig. 14C, D), and on both surfaces of sporophylls.
In the past, specimens of S. sematophylla were identifi ed as S. fragillima (= S. vestiens, which see for discussion). Selaginella sematophylla diff ers from S. vestiens by cell types on leaf surfaces, median leaf apex shape, and habit, as discussed in the diagnosis.