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Resurrection plants of the Selaginellaceae are renowned for their ability to tolerate desiccation as well as the small size of their nuclear genomes. These traits position Selaginella as a promising model system to understand many aspects of plant evolution. However, there is not an established method for the laboratory cultivation of resurrection species of Selaginella. We explored methods of in vitro propagation for resurrection species of Selaginella and identified a set of successful techniques. Our in vitro propagation system included two main steps: surface-sterilized megaspores were cultured alone on C-Fern agar medium for three weeks, followed by the addition of surface-sterilized microspores to the germinated megaspore cultures for co-culture. Sporelings of Selaginella eremophila and S. rupincola were observed after 2–5 weeks of co-culture, and all sporelings survived. Our methods aim to further the interest and use of resurrection species of Selaginella for manipulative studies to better understand the biology of desiccation tolerance and their unique genome architecture.

As part of a revision of Selaginella subg. Heterostachys in Central and South America, S. hyalogramma Valdespino is described as a new species and illustrated with a line drawing, as well as with scanning electron microscope (SEM) images of leaves, sporophylls, and megaspores. This new species is characterized by non-articulate stems, heteromorphic vegetative leaves with idioblasts on their upper and lower surfaces that are also present on sporophylls, as well as dorsiventral, resupinate strobili and a laminar flap on lower surfaces of dorsal sporophylls. These characters serve to compare it to morphologically similar taxa. In addition, the presence of stomata along basiscopic leaf margins and basiscopic submarginal short or tooth-like hairs on upper surfaces of lateral leaves of this species are reported and discussed. Finally, S. hyalogramma is only known from a single collection made in the State of Tachira, Venezuela, where it grows as an epipetric plant on mossy sandstone areas that may be s...

One of the challenges when working with the genus Isoetes is the scarcity of in-depth comparative analyses of its morphological characters. This paucity of analyses relates in part to the long-held conclusion that most of the characteristics associated with the traits of the genus aside from spore morphology, are too variable to be informative. As a result, our understanding of morphological variability among species of Isoetes is underdeveloped. Recent workers have attempted to address this deficiency by examining the glossopodia of the ligule, a structure unique among living taxa to Isoetes and its sister genus, Selaginella. The glossopodium is embedded in the adaxial surface of the microphyll, and has shown evidence of interspecific variability in the few studies in which it has been examined. However, these prior works were limited to qualitative comparisons. The present study compares 3D reconstructions of the glossopodia of three species, Isoetes howellii, I. bolanderi and I. nuttallii, usi...

The lycophyte genus Selaginella has a worldwide distribution with ca. 800 species. The genus is heterosporous and has ornamentation on the surface of both the megaspores and the microspores. Selaginella megaspore ornamentation is highly variable in both its macro- and microsculpture. Megaspore ornamentation is a species-specific morphological feature that can be used reliably for specimen identification. We present the first investigation of the megaspore surface of all 19 Selaginella species known from the state of Sao Paulo, Brazil, using scanning electronic microscopy (SEM). This study also includes Selaginella species that are invasive in Brazil. Based on the SEM analysis and high-resolution photographs, we provide detailed megaspore descriptions and an identification key for all species from Sao Paulo state. We also describe the proximal and distal pole ornamentation of the megaspores as well as the form and proportions of the trilete aperture.

The microphylls of Selaginella bear structures that have been given names as diverse as idioblasts, papillae, sclereids, fibers, and warts, yet they resemble silica bodies. However, for most species of the genus, no study has ever shown the composition of these structures or proven their nature comprehensively. Based on scanning electron microscopy and energy dispersive X-ray spectroscopy analyses, we confirmed the presence of silica bodies in microphylls of Selaginella, described four distribution patterns of the structures, and carried out a terminology review. The presence of silica may be related to mechanical protection of the cell wall, activation of defense mechanisms, and providing support for microphylls. Further in-depth analyses based on studies on the evolution of this character remain necessary to elucidate its relevance for the ecological relationships and systematics of Selaginella.

Veracruz, with 542 recorded species, is the third richest state in Mexico in terms of total fern diversity. Field work, herbarium studies, and a revision of literature during the last decade revealed 22 new state records. Five of these belong to Elaphoglossum, four are filmy ferns, and three are grammitids. Most of the new taxa were collected in the endangered humid montane and pine-oak forests of the central and Los Tuxtlas area during recent research projects. Another 13 species, mainly within Elaphoglossum and Selaginella, have been published as new records in the literature. Whereas several of these might possibly be confirmed in the future, others form part of poorly known species complexes that require specific studies, and we consider them as doubtful or unverified. Our study highlights the need of more fern inventories in remote and mostly unexplored areas, as well as revisions of national and local herbaria, both of which may reveal additional species new to science or range extensions.

Nuclear genome size is highly variable in vascular plants. The composition of long terminal repeat retrotransposons (LTR-RTs) is a chief mechanism of long term change in the amount of nuclear DNA. Compared to flowering plants, little is known about LTR-RT dynamics in ferns and lycophytes. Drawing upon the availability of recently sequenced fern and lycophyte genomes we investigated these dynamics and placed them in the context of vascular plants. We found that similar to seed plants, median LTR-RT insertion times were strongly correlated with haploid nuclear genome size. Fern and lycophyte species with small genomes such as those of the heterosporous Selaginella and members of the Salviniaceae had recent median LTR-RT insertion times, whereas species with large genomes such as homosporous ferns had old median LTR-RT insertion times intermediate between angiosperms and gymnosperms. This pattern holds despite methylation and life history differences in ferns and lycophytes compared to seed plants, and our results are consistent with other patterns of structural variation in fern and lycophyte genomes.

A simple and efficient protocol for isolating genomic DNA from leaves of Selaginella spp. (S. delicatula, S. repanda, S. bryopteris, S. plana, S. monospora) was developed, involving a modified CTAB protocol of Rogers and Benedich (1994). Increasing the incubation time with the precipitation buffer (1X CTAB) from 1–3 hours to 12–14 hours helped achieve higher quantity genomic DNA from the specimens, when compared with DNA extracted by protocols reported by Dellaporta et al. (1983), Murray and Thompson (1980) and Doyle and Doyle (1987). The DNA yield ranged from 846–1836 µg/ml from fresh and herbaria-preserved leaf samples. The DNA samples were found suitable for genetic diversity analysis with Random Amplified Polymorphic DNA (RAPD) markers. Nine random primers (OPA A17, OPB 4, OPB13, OPC 2, OPC 11, OPD 5, OPG 2, OPG 19 and OPK 10) were studied, of which two primers (OPD 5 and OPG 2) yielded reproducible amplification profile of polymorphic fragments.

The present investigation presents a clear differentiation between the articulated and non-articulated stem of Selaginella, based on morphological and anatomical characteristics. We also take the first step in developing a clear definition of the articulated stem in Selaginella. Further, in Selaginella anaclasta previously described as having articulate stems, we found no micro-morphological or structural evidence of articulations, and we describe this species as one with non-articulated stems. In support of our findings, we present micromorphological and structural descriptions of three species S. anaclasta, S. exaltata, and S. parviarticulata, which differentiate the various stem constructions in Selaginella.

The ligule morphology in three Indian species of the genus Selaginella, e.g., S. bryopteris, S. repanda and S. panchghaniana is described for the first time. Though the leaves (ventral and dorsal) in all the three species are typically normal, some dorsal leaves in S. panchghaniana have two ligules, bifid tips and lobed bases. The form of ligules is variable within each species but the overall shape (outline) is constant. The size of ligules may be influenced by environmental conditions. The presence of glandular cells at the margin of the tip of ligules indicates a water secreting function.

In 1853 J. R. Riddell validly published seven binomials of pteridophytes for species from Alabama, Louisiana and Texas that were missed by the standard indices. Only one of these names, Lycopodium corallinum, is the first name validly published for a currently recognized species replacing Selaginella riddellii. The six other binomials prove to be later synonyms of species of Adiantum capillus-veneris, Cheilanthes alabamensis, Dryopteris ludoviciana and D. kunthii, Pellaea ovata and Thelypteris hispidula.

One of the most distinctive features of the heterosporous lycopsids is the presence of a ligule. This structure, currently found only in Isoetes and Selaginella, is comprised of a basally embedded glossopodium and a free distal tongue. Previous studies on Indian species have demonstrated small variations in glossopodia suggesting the possibility that this structure could have taxanomic use. Serial cross, paradermal, and sagittal sections of glossopodia from three different North American species, representing three ploidy levels, were made. Three-dimensional digital rendering of the glossopodia provided comparative data for the three North America species and allowed comparisons with previously published descriptions. In general, the shape of the glossopodium is similar in all three North American species. There are several structural differences among them, such as the shape of the cornua, the length of the medimoles, and the angle of the glossopodium relative to the leaf axis.

Ultrastructural details of the mature pre-released spermatozoid of Selaginella australiensis are presented with a three-dimensional model based on these data. This sperm cell is highly elongated and coils for nearly three revolutions. A parallel band of spline microtubules runs around the periphery of the cell and forms the structural framework along which the four organelles are aligned. Numbers of microtubules in the spline begin with one at the tip of the cell and progressively increase to 19 toward the cell posterior. The locomotory apparatus consists of two staggered monomorphic basal bodies, referred to as the anterior and posterior basal bodies, and their corresponding axonemes. Typically, no remnant of the lamellar strip is visible in the mature spermatozoid. The anterior mitochondrion occupies over 1/ gyres at the front of the cell and as such is the largest organelle. It is inserted immediately behind the anterior basal body and underlies the posterior basal body/axoneme for over one revolution. The posterior axoneme is retained within the cell body over the spline and anterior mitochondrion. The nucleus extends approximately one gyre and is situated between the anterior mitochondrion and a smaller posterior mitochondrion. At the rear of the cell is a plastid that contains two large juxtaposed starch grains. Similarities of this cell with other lycophytes include the staggered monomorphic basal bodies and increase in spline microtubules from front to back. Commonalities with bryophyte and charalean spermatozoids include cellular organization and shape, and the lack of a lamellar strip in the mature cell. Selaginella is a key taxon in understanding the early events in land plant diversification (DiMichele and Skog, 1992). The fossil record of this phylogenetically significant genus dates back to the Carboniferous, making Selaginella second only to Lycopodium in geological age (Bierhorst, 1971). Living representation of this lycopsid is extremely diverse, with over 700 species worldwide (Webster, 1992; Valdespino, 1993). Yet, the precise placement of Selaginella in the plant kingdom is unclear. The paucity of detailed comparative studies on anatomical and ultrastructural features of lycopsids, and especially the ligulate taxa, has confounded resolution of relationships among these basal plant lineages (Garbary and Renzaglia, in press). Clearly, additional studies on this taxonomically complicated and phylogenetically crucial genus are warranted. Spermatogenesis has proven to be a rich source of phylogenetic information (Garbary et al., 1993; Mishler et al., 1994; Duncan et al., 1997; Maden et al., 1997). The major limitations in using male gametogenesis for phylogenetic reconstructions are the low numbers of organisms that have been investigated and the incomplete data sets for those taxa that have been observed. In bryophytes, much attention has been placed on elucidating the microanatomy of This content downloaded from 157.55.39.147 on Wed, 20 Apr 2016 04:41:16 UTC All use subject to http://about.jstor.org/terms AMERICAN FERN JOURNAL: VOLUME 88 NUMBER 1 (1998) the locomotory apparatus or blepharoplast (Carothers and Rushing, 1988; Renzaglia and Duckett, 1991). Few studies of developmental processes and mature cell structure have been undertaken (Vaughn and Renzaglia, in press). In pteridophytes, even fewer organisms and structural features have been documented than in bryophytes (Duckett 1973; 1975; Duckett and Bell, 1977). Ultrastructural observations of Selaginella spermatogenesis is limited to one species, S. kraussiana (Kunze) A. Braun. In gross morphological features, this spermatozoid bears an uncanny resemblance to those of bryophytes. Although an idealized reconstruction of the mature cell for this species was presented by Robert (1974), many details of the cellular organization remain unclear. Thus, we undertook an ultrastructural investigation of the mature sperm cell of a second species of Selaginella, S. australiensis Baker. Descriptions of precise structural features and a three-dimensional reconstruction of the cell based on these data are presented. Comparisons are made with motile gametes from a wide range of green plants, with emphasis placed on identifying similarities and differences among biflagellated gametes of Selaginella, Lycopodium sensu lato, bryophytes and Charales. MATERIALS AND METHODS Selaginella australiensis was collected in the rainforest on Mount Wilson, Blue Mountains, New South Wales, Australia, in October, 1991. Plants were maintained in the greenhouse and monitored for sporangial production. Mature microsporangia were dissected and placed on filter paper moistened with distilled water in petri plates. The plates were sealed with parafilm and placed in an incubator at 20?C with a 12 hr light/dark cycle. After 10 days, the cultures were examined daily until swimming sperm cells were detected. Because of differing rates of microgametophyte development among the several microsporangia per plate, cultures harvested at the first sign of mature spermatozoids generally contained all stages of spermatogenesis. Microsporangia were lifted from the filter paper and placed in microfuge tubes containing 6% glutaraldehyde in 0.05 M Pipes buffer (pH 7.4). Microspores were liberated from sporangia and gently cracked with the end of a flame-sealed Pasteur pipet. Without mechanical disruption of spore walls, fixative and resin will not penetrate the microgametophyte. After immersion in the primary fixative for 2-4 hr, the microspores were washed four times in 0.1 M cacodylate buffer (pH 7.2) and post fixed in 2% Os04 in the same buffer for 2 hr. Prior to withdrawing solutions, the spores were pelleted in a microcentrifuge for 30 sec. After washing with distilled water, the spores were "en bloc" stained in 1.0% aqueous uranyl acetate for 16 hr at 4?C. The specimens were rinsed in distilled water, dehydrated in a graded acetone series, replaced by propylene oxide, infiltrated slowly over approximately one week with 1:1 Spurrs/Embed 812 resin, embedded and cured at 60?C for 16 hr. Thin sections were collected on copper grids and post-stained with 2% uranyl acetate in ethanol and basic lead citrate for five min each. Grids were observed on a Philips 201 or Hitachi 7100 TEM. 2 This content downloaded from 157.55.39.147 on Wed, 20 Apr 2016 04:41:16 UTC All use subject to http://about.jstor.org/terms RENZAGLIA ET AL.: SPERMATOZOIDS OF SELAGINELLA All micrographs of cross sections are oriented as if viewing from the anterior of the cell, i.e., from the front of the MLS. In such an orientation, the triplet and double microtubules in basal bodies and flagella overlap in a counterclockwise direction. References to right and left in the text refer to this orientation.

The evolution of heterospory changed the conditions for spore dispersal. Assuming wind as the dispersal agent, microspores will be dispersed to greater distances than megaspores. We investigated aspects of spore size and sculpture as well as spore dispersal under calm con- ditions and under the effect of artificial wind of some Selaginella species. We found that differ- ences between the species existed that were correlated with active or passive release of micro- and megaspores. The dispersal efficacy changed drastically under the effect of wind, showing differences between the species. There was no support for the hypothesis of synaptospory between micro- and megaspores during active dispersal. Evidence suggests that active spore dispersal and wind may enhance outbreeding. More detailed investigations may reveal species specific corre- lations between life history traits, breeding systems, and spore dispersal. Heterospory and dioecy of gametophytes evolved independently in different clades of the pteridophytes. The separation of female megaspores and male microspores changed the conditions of spore dispersal. In homosporous, wind dispersed ferns the probability of being transported a certain distance is much the same for each spore. Assuming that in heterosporous pteridophytes wind dispersal is still dominant, the smaller and lighter microspores are likely to be dispersed to longer distances than the larger and heavier megaspores (Tryon and Lugardon, 1991). The dispersal distances of male and female gameto- phytes thus differ. Heterospory also affects the production of spores. Because of higher energetic investments, the number of megaspores per individual plant is reduced in comparison to the number of microspores (Tryon and Tryon, 1982). As a consequence, the dispersal ecology of heterosporous pte- ridophytes is likely to differ from that of homosporous ferns (Cousens, 1988). The heterosporous genus Selaginella P. Beauv. is widespread and contains numerous species (Jermy, 1990). The efficacy of their active spore dispersal mechanisms was first investigated by Goebel (1901). He showed that the mega- sporangium ejects the megaspores in a manner quite different from the micro

Chloroplast 16S rDNA sequences from the charophyte algae Spirogyra and Coleo- chaete; the bryophytes Marchantia and Sphagnum; the fern allies Equisetum, Isoetes, Selaginella, Lycopodium, Tmesipteris and Psilotum; the eusporangiate ferns Angiopteris, Botrychium, and Ophioglossum; the leptosporangiate ferns Lydogium and Doodia; the gymnosperms Ephedra and Juniperus; and six angiosperms (two monocots and four dicots) were analyzed with the parsimony algorithm PAUP to infer phylogenetic relationships. The charophytes were the designated out- group and the bryophytes were at the base of the land plant clade. Relationships of most of the fern allies and Angiopteris were unresolved but a clade containing Psilotum + Tmesipteris (Psi- lotales) was sister to a clade composed of Botrychium and Ophioglossum (Ophioglossales). A leptosporangiate fern clade was strongly supported, and this clade grouped weakly with Angiop- teris. The Selaginella 16S rDNA sequence is apparently changing at a faster rate than the other sequences as evidenced by the extremely long branch associated with Selaginella. The effect of this long branch on the overall tree topology was tested by removing Selaginella from a subsequent analysis. Trees produced without Selaginella weakly supported the placement of Lycopodium at the base of the vascular plants clade but Isoetes grouped weakly with the seed plants. Removal of Selaginella also resulted in higher bootstrap values and decay indices for the majority of the clades. The determination of phylogenetic relationships of the "fern allies," the Psi- lophyta, Lycophyta, and Sphenophyta, has proven to be elusive. Taxonomi- cally, the fern allies are generally considered to be positioned between the bryophytes and ferns but formal analyses of morphological and molecular data sets only partially resolve their relationships. In a cladistic analysis of mor- phological characters, Bremer et al. (1987) placed Psilotum at the base of vas- cular plants, the lycopsids branched off next, then Equisetum, and then the ferns. However, the portion of the clade containing the fern allies was con- structed with only four morphological characters and it is not reasonable to expect that a robust phylogeny containing highly divergent taxa can be pro- duced from such a small data set. Conversely, fossil evidence (Knoll and Roth- well, 1981; Stewart, 1983; Gensel and Andrews, 1984), characters relating to male gametogenesis (Garbary et. al., 1993), and chloroplast genome structures (Raubeson and Jansen, 1992) support the hypothesis that the lycophytes are at the base of the vascular land plant clade. Mishler et al. (1994) analyzed green plant molecular and morphological data sets separately and together, using parsimony algorithms. Some vascular land plants were included, with the fern allies represented by Equisetum, Lycopo- dium, Lycopodiella, and Selaginella. The analysis of "general" morphological characters placed the lycophytes sister to a clade containing Equisetum, ferns

Mexico with its ca. 76 species of Selaginella has the third highest number of species of any country in the New World. During the course of my preliminary studies aimed to prepare the treatment of the family Selaginellaceae for the Pteridoflora of Mexico Project (Mikel, Smith, Palacios-Rios, and collaborators, in prep.), a new species was uncovered among a loan of Selaginella specimens from Veracruz sent to me by M. en C. Monica Palacios-Rios (XAL). Later, Biol. Horalia Diaz Barriga (IEB) provided me with additional material of the new species from Queretaro. Since this novelty is to be included by Biol. Diaz Barriga (pers. comm.) in her treatment of the genus Selaginella for Flora del Bajfo, a formal description is required, which I provide below. Further additions to Mexican Selaginella are foreseen as ongoing studies by the author continue.

The Japanese Twin-sorus Fern, Diplazium japonicum (Thunb.) Bedd., has been reported as escaped from cultivation in Gadsden County, Florida since 1957 (Wherry, 1964), and recently Short (1980) published an account of its discovery in Lee County, Alabama. This species subsequently has been found in three widely disjunct locations in Georgia (Fig. 1). In late summer of 1980, my wife and I led a fern field trip in central south Georgia for the Georgia Botanical Society. During the field trip, Marge White and Frieda Polsfuss (fern hobbyists from middle Georgia) showed several of us some pressed fronds of a fern which Mrs. White had collected in Houston County, Georgia. Upon superficial examination, most of us identified the plant as a form of Athyrium, although the possibility of its being a Diplazium was suggested. A frond was given to Lloyd H. Snyder, Jr. (a fern hobbyist from Atlanta), who discovered the same fern beneath a highway bridge in Berrien County, Georgia the following day. Specimens from Houston and Berrien Counties were shown to Dr. Murray Evans of the University of Tennessee, who confirmed the identity of both as Diplazium japonicum. The two sites were rechecked in October to determine the extent and condition of

Various methods for obtaining microgametophytes, megagametophytes, and sporelings of Selaginella have been described. Slagg (1932), in a study of microgametophyte development in S. kraussiana (Kunze) A. Br., germinated microspores on plaster of Paris blocks. A similar method for germinating both microspores and megaspores was described by Bold (1967). Bierhorst (1964) described methods for obtaining reproductive stages of Selaginella for classroom use. Webster (1967) described the induction of sporelings under greenhouse and field conditions. Wetmore and Morel (1951) germinated megaspores of S. pallescens (Presl) Spring in Mart. and S. flabellata (L.) Spring on nutrient agar under sterile conditions. Through the use of a medium supplemented with various growth factors, they were able to grow gametophytic tissue for several months. Despite the above procedures for germinating spores and obtaining sexual material of Selaginella, there is but one report of artificial crosses in the genus. Burgeff and Filippi (1957) made crosses between S. martensii Spring var. martensii and S. martensii var. variegata Hort. They sowed surface-sterilized megaspores and microspores together on nutrient agar in culture tubes and, after gametophytes had formed, flooded the cultures with water to achieve fertilization. After 30-40 days, sporelings appeared. Using this method, they studied the inheritance of variegation in S. martensii var. variegata. In this paper, a crossing technique differing in several respects from the one used by Burgeff and Filippi (1957) is described. Although it has been used successfully to repeat the crosses by Burgeff and Filippi, the technique was developed for making crosses with S. kraussiana and its varieties, and the following description is based on work with these taxa. Application of this technique to a study of inheritance of pigmentation in S. kraussiana var. aurea W. Bull will be the subject of a later report.

More subtle differences between the two species were revealed by anatomical studies of stems and leaves (Buck, 1974) and by examination of spores with the light microscope and the scanning electron microscope. For instance, in S. ludoviciana stomata are restricted to a few rows adjacent to the midribs of the leaves (Fig. 5), whereas in S. apoda they are scattered throughout the laminae (Fig. 2). Also, examination of leaf clearings and scanning electron micrographs showed a high percentage of papillate cells scattered throughout the lower epidermis of S. ludoviciana leaves and very few, if any, on those of S. apoda (Figs. 2 and 5). Comparisons of the spores of the two species reveal other differences. Knox (1950) described the microspores of both species as being warty with crenate margins. Hieronymus (1900), however, distinguished the species by their microspore morphology, describing those of S. ludoviciana as smooth and those of S. apoda as warty, verrucose, or irregularly rugose. In our study, we consistently found the microspores of S. ludoviciana to be smooth and those of S. apoda to be warty when viewed with the light microscope, thus confirming Hieronymus' findings. When viewed with the SEM, the microspores of S. apoda can be described as rugulo-reticulate (Figs. 8 and 9) to verrucate. Terminology for these spore wall descriptions is based primarily on that defined by Harris (1955). In some specimens (Fig. 7) the spores of S. apoda are covered with small spicules or papillae. In S. ludoviciana the so-called smooth spores are in fact covered with short papillae or spicules (Figs. 10-12). Measurements of microspores from 16 specimens of each species failed to show a significant size difference (x = 26.47ium for S. apoda and x = 27.24,m for S. ludoviciana).

In recent years, phloem structure and development in vascular cryptogams have received much attention. Among the genera that have been studied are: Selaginella (Burr & Evert, 1973), Polypodium (Evert & Eichhorn, 1973), Isoetes (Kruatrachue & Evert, 1974), Microsorium and Psilotum (Sakai & Lamoureux, 1973), Cyathea and Pteris (Shah & Fotedar, 1974 a, b), and Lycopodium (Warmbrodt & Evert, 1974). Indian vascular cryptogams have received scant attention in this regard and require investigation.

One of the most distinct taxonomic groups in the genus Selaginella is the series Articulatae, comprised of about 40 taxa endemic to Latin America, one species that is in South Africa, the Azores and Latin America, and several that are restricted to Southeast Asia. This heterophyllous group, first described by Spring (1850) and maintained in later classifications by Hieronymus (1901) and Walton and Alston (1938), takes its name from the articulations located just below each bifurcation of the stem. These appear either as dark-colored swellings in living material or as dark constrictions in some dried specimens. Other morphological characteristics that unify the group are: (1) each strobilus has only a single (or rarely two) basal megasporangia; (2) each enlarged fertile megasporophyll is subtended by one or more enlarged sterile leaves; (3) the megaspores are exceptionally large and have high crestoreticulate muri; (4) the microspores are pale (usually buff to tan) and have ornamentation of sharp spines on their exines; and (5) the aerial roots arise dorsally from the stem. Also, about three-fourths of the taxa in the series have bistelar or multistelar stem anatomy, a feature not found elsewhere in the genus. During a taxonomic survey of the Articulatae, a previously undescribed type of microsporangium was found to be another unifying feature. A survey of nearly all of the articulate taxa and many non-articulate ones supported this generalization. An explanation of the survey and a description of the microsporangia follows.

Selaginella eatonii Hieron. ex Small has long been relegated to synonymy under S. armata Baker, but actually it is a distinct species. The plants are among the smallest known in this predominantly tropical genus. Selaginella eatonii and the West Indian S. armata are both members of subg. Stachygynandrum (Pal. Beauv.) Baker, which is characterized by having dorsiventrally flattened shoots comprising two lateral rows of larger leaves plus two medial rows of smaller leaves. According to Baker's (1883-1885) scheme of classification, S. eatonii is closely related to the other heterophyllous Selaginellae of eastern North America, namely S. apoda (L.) Spring, S. eclipes Buck, and S. ludoviciana A. Braun. When J. K. Small (1918, p. 67) originally described S. eatonii, he credited Hieronymus with being the author. No specimens of it were cited, although Small reported the plant as growing on limestone in the "Everglade Keys;" he also stated that the plant was first collected in 1903. The species is quite rare in South Florida.

During a recent survey of pteridophytes of southeastern Rajasthan, India carried out in September 1977, we collected a Selaginella which is different from all the known species of this genus. It is being described now as a new species, and is an addition to the 59 species of the genus already recorded from India (Alston, 1945; Panigrahi & Dixit, 1966a, p. 11, 1966b, 1967, 1968; Bole & Almeida, 1977).

Cuba, Jamaica, and parts of South America. The species belongs to the heterophyllous subg. Stachygynandrum, which is characterized by the stems (at least distally) and the vegetative leaves of branches having 2 rows of smaller, usually appressed, median leaves and 2 rows of larger, spreading lateral ones. Contrasting with this is subg. Selaginella, with plants homophyllous throughout, i.e., leaves are borne on all sides of the stem and branches and all are appressed for most of their length. Subgenus Stachygynandrum is sharply divided into two groups, one having stems articulate, or at least constricted at or near the nodes and here usually discolored, and with rhizophores produced dorsally. The other group, containing S. pallescens, has stems neither articulate nor with discolored or constricted nodes, and with rhizophores produced ventrally, Selaginella pallescens and its nearest relatives commonly have the stems densely caespitose, often forming rosettes. They tend to curl inward when dry, then uncurl again when moisture is introduced, thus giving rise to the common name "Resurrection Plant." Taxonomy of the entire S. pallescens complex in the neotropics needs careful re-examination. There are several species which I feel are not truly distinct, and yet there are some hitherto unrecognized variants, which perhaps should be formally treated as varieties or forms. Some very closely related species are: S. cuspidata (Link) Link and var. elongata Spring, S. harrisii Underw. & Hieron., S. microdendron Bak., S. millspaughii Hieron., and S. pulcherrima Liebm. During a study of the genus for the "Ferns and Fern Allies of Guatemala," it appeared to me that most of these species might better be included under S. pallescens, for whatever differences were noted by previous authors appear to be thoroughly inconsistent. On the other hand, some new features have come to light which seem significant and consistent enough to indicate recognition of some specimens at the varietal level. In his study of the spores of heterophyllous Selaginellae, Hellwig (Ann. Mo. Bot. Gard. 56:41/1 164. 1969) annotated a number of specimens in various herbaria as S. pallescens, "red-stemmed variant." Some other minor features have been discovered to be consistent with stem color on these specimens, and the combination of

The following list represents collections made by the writer in the vicinity of Keyport and in other parts of New Jersey. Seventy-nine different forms are included, of which sixteen are in the genera Equisetum, Lycopodium, Selaginella and Isoetes, leaving the number of ferns at sixty-three. The list includes all but four of the fifty fern species recorded from New Jersey in Norman Taylor's recently published Flora of the Vicinity of New York and to a certain extent supplements that work, which takes no account of varieties and gives no localities at which the hybrids mentioned have actually been found. One of these hybrids, named here as Dryopteris Clintoniana x cristata, has never been regularly described,' but the plant is fairly distinct and not difficult to recognize. The plants mentioned in the list are all represented by herbarium specimens.

The genus Selaginella has been a popular subject of study for over 100 years. Its unique and still enigmatic organ, the rhizophore, has attracted many investigators; aspects of the plants' reproduction have been studied by other workers. Since heterospory represents a major step in the evolution of the seed, Selaginella has been a favorite example in plant morphology courses. Many papers have been published on the genus. Although several general morphological and anatomical studies have been made (Hieronymus, 1902; Harvey-Gibson, 1894; Steel, 1923; Wardlaw, 1925; Zamora, 1960), very few of the approximately 700 species have been thoroughly investigated. Recent authors have discussed its spores (A. Tryon, 1949; Hellwig, 1969), sporangial arrangement (Horner and Arnott, 1963), and the root and rhizophore in light of new evidence (Webster and Steeves, 1963, 1964). Certain other morphological features have been pointed out in the taxonomic treatments of Alston (1955) and R. Tryon (1955). Several stelar types have been described in the genus (HarveyGibson, 1894). By far the most common types are the ribbonshaped monostele and the bistelic type (two separate round protosteles). More elaborate stelar patterns have been recognized: (1) three or more stelar ribbons in all stem axes; (2) two ribbons in the rhizome and one in the erect stem with a ventral round bundle; and (3) a solenostelic rhizome and polystelic erect stem. During a course in the biology of tropical pteridophytes in Costa Rica for the Organization for Tropical Studies (Mickel, 1967), the senior author preserved material of Selaginella exaltata (Kunze) Spring, a species notable for its large size (Fig. 1). Plants may reach more than a meter in height, with megaspores up to 1.5 mm in diameter. There is no creeping rhizome. The stem is erect, reaching a diameter of 5 mm in the lower internodes and 8 mm in the swollen "nodes" (sites of stem ramification), and is supported by several rhizophores up to 35 cm long and 2 mm in diameter. 123

The Grand Canyon has always had a fascination for me and I've been down the Hermit Trail once to the river, the Bright Angel Trail several times, and the Grand View Trail to where it ended. The time of year was not promising and I had very little success in finding any ferns. On one trip in late September, after the late summer rains, on the Bright Angel Trail I found Cheilanthes Feei, Notholaena Parryi, and Pellaea longimucronata. When one walks down and up those steep trails, carrying an increasingly heavy press, there is no leisure to search for these inconspicuous plants. After all, whenever I have come across these attractive little ferns I have been

LYCOPODIUM COMPLANATUM L. Var. FLABELLIFORME Fernald. Common. LYCOPODIUM TRISTACHYUM Pursh. Sunny hillside at Lake Grubb, near the Marietta Pike. SELAGINELLA APUS Spring. Common. In 1925 or 1926 one of our group, Mr. William H. Auxer, found Lygodium palmatum (Bernh.) Sw, in the neighborhood of Penryn Park. He was not then interested in ferns and did not realize that it was an unusual find, although he collected a specimen for his herbarium. We have searched for it since, but so far unsuccessfully. We also found Dryopteris simulata just across the river, in York County, but not within our own county limits.

Modern classifications of the ferns and lycosphens ("fern-allies") group them into various Classes, all of which along with the Gymnospermae and Angiospermae are called the Tracheophyta ("vascular plants"), in allusion to the development of a vascular system, in distinction to the Bryophyta and other lower, non-vascular groups. There are four classes of Tracheophyta now recognized. The Psilopsida include Psilotum and Tmesipteris; the Lycopsida, Lycopodium, Selaginella, and Isoetes; the Sphenopsida, Equisetum; and the Pteropsida, the Filicineae (ferns), Gymnospermae, and Angiospermae. The first three, along with the Filicineae, were formerly grouped as Pteridophyta in older classifications. In earlier years the forms for names above the rank of genus were not definitely prescribed, and the same name was often used to represent an order, a family, or a tribe, without change in the termination.' The present International Code of Botanical Nomenclature (1952) specifies the terminations to be used: Divisions to end in

Three species of Selaginella of the group commonly known as resurrection-plants are found in the United States, namely, S. lepidophylla (H. & G.) Spring, S. pilifera A. Br., and S. Pringlei Baker. All three are native in western Texas. The first, which has recently been recorded from New Mexico2 is readily distinguished by its white-margined, obtuse leaves. The other two species, which have leaves bearing a long terminal seta, are very closely related. In attempting to identify a specimen recently collected in the Guadalupe Mountains

The water-ferns, represented by Salvinia and Azolla, are among the most curious of plants, and would not ordinarily be taken to be related to the ferns. Salvinia plants consist of a shoot up to one or two inches long, with clusters of round floating leaves rarely as much as a centimeter in diameter. Azolla likewise is a floating plant, chiefly of the tropics; the entire surface of quiet ponds may be so covered by the tiny branching fronds as to exclude mosquitoes from the surface, and for this reason the plant is sometimes known as "mosquito-fern" (cf. Benedict, AMER. FERN JOURN. 13: 48. 1923). These little floating plants send rootlets down into the water much in the manner of the duckweed (Lemna); their small size, branching habit, and the almost crystalline appearance of the tiny individual leaves may be judged from the accompanying drawings of living, non-fruiting plants from the greenhouses and out-door pools of the Brooklyn Botanic Garden (Pt. 6, fig. 1). The succulent leaves, in the center of which blue-green algae always live, gleam under the lens like leaves of Mesembrianthemum. In full sunlight the fronds often become reddish, but those in shaded localities remain bright green. The branches of Azolla show a dorsiventral structure suggesting that of Selaginella. The leaves are two-lobed, the lower lobe being usually larger than the upper, mostly