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Summary The primary vascular system of plants (the stele) has attracted interest from paleobotanists, developmental biologists, systematists, and physiologists for nearly two centuries. Ferns, with their diverse stelar morphology, deep evolutionary history, and prominent fossil record, have been a major focus in studies of the stele. To explain the diversity of stelar morphology, past adaptive hypotheses have invoked biomechanics, hydraulics, and drought tolerance as key selection pressures in the evolution of stelar complexity; but, these hypotheses often isolate the stele from a whole‐plant developmental context, ignoring potential covariation between vascular patterning and shoot morphology. Furthermore, incongruence between expected patterns and observed data challenge adaptive hypotheses, precluding a comprehensive explanation of stelar evolution. While ontogeny has been previously recognized as a factor in stelar diversification, it has not been fully integrated into a comprehensive framework. Here we synthesize 150‐years of research on stelar morphology, incorporating developmental, physiological, and phylogenetic data to present the ontogenetic hypothesis of stelar evolution. This hypothesis posits that stelar morphology is an integrated feature of whole‐plant ontogeny, not a trait shaped by direct selection for adaptive patterns. This shift in perspective provides an updated framework for understanding the determinants of stelar morphology and focusses future efforts to ask more incisive questions about the evolution and function of primary vascular architecture. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Taxon Methods Results Main Conclusions Ferns are globally distributed, yet the number of studies examining the historical evolution of African taxa is relatively low. Investigation of the evolution of African fern diversity is critical in order to understand patterns and processes that have global relevance (e.g., the pantropical diversity disparity [PDD] pattern). This study aims to examine when and from where a globally distributed fern lineage arrived in sub‐Saharan Africa, to obtain a better understanding of potential processes contributing to patterns of diversity across the region.Global, sub‐Saharan Africa.Asplenium (Aspleniaceae).We analysed five loci from 537 Asplenium taxa using a maximum likelihood (IQ‐Tree) phylogenetic framework. For age estimation, we performed penalised likelihood as implemented in treePL, and executed a Bayesian analysis using BEAST. Biogeographical analyses were carried out using BioGeoBEARS.Most dispersals into Africa occurred within the last ~55 myr, with the highest diversity of sub‐Saharan African taxa concentrated in two clades, each of which descended from an Asian ancestor. Additional dispersals to sub‐Saharan Africa can be found throughout the phylogeny. Lastly, potential cryptic species diversity exists within Asplenium as evidenced by several polyphyletic taxa.We recover multiple dispersals of Asplenium to sub‐Saharan Africa, with two major lineages likely diversifying after arrival. [ABSTRACT FROM AUTHOR]

SUMMARY Ferns (Pteridophyta), as the second largest group of vascular plants, play important roles in ecosystem functioning. Homosporous ferns exhibit a remarkable range of mating systems, from extreme inbreeding to obligate outcrossing, which may have significant evolutionary and ecological implications. Despite their significance, the impact of genome‐wide inbreeding on genetic diversity and mutation load within the fern lineage remain largely unexplored. In this study, we utilized whole‐genome sequencing to investigate the genomic signatures of inbreeding and genetic load in three Alsophila tree fern species. Our analysis revealed extremely high inbreeding in A. spinulosa, in contrast to the predominantly outcrossing observed in A. costularis and A. latebrosa. This difference likely reflects divergent mating systems and demographic histories. Consistent with its extreme inbreeding propensity, A. spinulosa exhibits reduced genetic diversity and a pronounced decline in effective population size. Comparison of genetic load revealed an overall reduction in deleterious mutations in the highly inbred A. spinulosa, highlighting that long‐term inbreeding may have contributed to the purging of strongly deleterious mutations, thereby prolonging the survival of A. spinulosa. Despite this, however, A. spinulosa carries a substantive realized genetic load that may potentially instigate future fitness decline. Our findings illuminate the complex evolutionary interplay between inbreeding and mutation load in homosporous ferns, yielding insights with important implications for the conservation and management of these species. [ABSTRACT FROM AUTHOR]

Summary The evolution of adjustable stomatal pores, enabling CO2 acquisition, was one of the most significant events in the development of life on land. Here, we investigate how the guard cell signalling pathways that regulate stomatal movements evolved. We compare fern and angiosperm guard cell transcriptomes and physiological responses, and examine the functionality of ion channels from diverse plant species. We find that, despite conserved expression in guard cells, fern anion channels from the SLAC/SLAH family are not activated by the same abscisic acid (ABA) pathways that provoke stomatal closure in angiosperms. Accordingly, we find an insensitivity of fern stomata to ABA. Moreover, our analysis points to a complex evolutionary history, featuring multiple gains and/or losses of SLAC activation mechanisms, as these channels were recruited to a role in stomatal closure. Our results show that the guard cells of flowering and nonflowering plants share similar core features, with lineage‐specific and ecological niche‐related adaptations, likely underlying differences in behaviour. [ABSTRACT FROM AUTHOR]

The recent discovery of Psilotum × intermedium in Mexico prompted us to reassess the nomenclature of this genus, which has global implications. From an extensive review of nomenclatural types and herbarium specimens, field collections, and a morpho-anatomical analysis, P. nudum and P. flaccidum are treated as accepted species, while P. × complanatum is treated as an interspecific hybrid between them. With this clarification, we specify their main synonymies and designate seven lectotypes (for Bernhardia schiedeana, Psilotum complanatum var. latissimum, P. complanatum var. mexicanum, P. floridanum, P. neocaledonicum, P. triquetrum, P. triquetrum var. gracile) and we select an epitype to give taxonomic support to the hybrid. We provide descriptions, diagnostic comments, and a key for identification of the accepted taxa, and also update the geographical ranges of these three taxa, mainly in Neotropics. [ABSTRACT FROM AUTHOR]

In anthropogenic islands as urban parks, the fern species richness and composition may be determined ecologically by the quality of habitat, including area greenness, or biogeographically by area size. As the development of the theory of island biogeography also includes man-made parks, it is feasible to test whether area-species relationship applies in these urban parks, and is more pronouncedly evident compared to another ecological factor, such as NDVI. Total species number and composition of 8 urban parks in a kecamatan (subdistrict) in Tegal Regency were collected and arranged in clustering methods to understand the similarity between parks. The similarity analysis result is important for the management of the parks in Slawi. The species richness data is subsequently tested using Pearson correlation and regression against NDVI and area sizes. The relation between NDVI and species richness is nonsignificant (p=0.058), while area size and species richness is significant (p=0.003). This signifies that the urban fern species richness is determined by area as biogeographical factor, compared to NDVI as ecological factor. This result is important for the purpose of designing and managing urban parks as evidently size is important in the effort of attracting native biodiversity into urban parks and in turn enhancing the well-being of urban population. [ABSTRACT FROM AUTHOR]

The fern independent gametophytes that can maintain populations by vegetative reproduction without conspecific sporophytes have been considered an unusual phenomenon found in some epiphytic or epilithic species of Hymenophyllaceae, Pteridaceae, Lomariopsidaceae, and Polypodiaceae. By chance, the discovery of mysterious strap-like gametophytes on Izu-Oshima Island, Japan, has led to the hypothesis that Hymenasplenium murakami-hatanakae, a fern species belonging to Aspleniaceae, can also form independent gametophytes. Our investigation revealed gametophyte populations of H. murakami-hatanakae on three islands in the Izu Islands. Based on chloroplast DNA analysis of the gametophyte and sporophyte populations, the gametophytes were found to be maintained by vegetative reproduction without a new supply of spores from sporophytes. A comparison of the surrounding vegetation at the collection sites showed that environmental factors such as light and humidity may influence the maintenance of gametophyte populations. These results clearly show that H. murakami-hatanakae is one of the ferns capable of forming independent gametophytes. This is the first report of independent gametophytes from the suborder Aspleniineae (eupolypod II). The discovery of the independent gametophyte within a phylogenetic lineage previously thought not to form independent gametophytes will provide important insights into the morphological and functional evolution of gametophytes in ferns. [ABSTRACT FROM AUTHOR]

Recent investigations have revealed the coordination and trade-offs between above- and belowground traits in structuring functional strategies of plant communities, but none of these have addressed ferns, a diverse plant lineage in tropical forests. We investigated terrestrial ferns from the perspective of how below- and aboveground traits are coordinated with functional responses to forest edges, which represent a significant part of the world's forest cover. Specifically, we examined differences in functional strategies between forest edges and forest interior as well as traits associated with species dominance. Fern richness and abundance were sampled in 24 edge plots and 44 interior plots within the Brazilian Atlantic Forest. We obtained data for five leaf traits and three rhizome traits. Ferns did not express any functional coordination between above- and belowground traits. At the edge, ferns did not display functional homogenization. In both the interior and at the edge, ferns exhibited multiple trait covariations across a broad spectrum of plant sizes and leaf numbers, associated with rhizome type and the presence of leaf trichomes and stolons. There were no cohesive functional groups of generalists or of exclusive species of forest edges and the forest interior. Fern species dominance was related to the species-specific number of leaves and the presence of stolons. We conclude that below- and aboveground traits did neither respond in conjunction nor as a functional response to edge effects. However, both kinds of traits affected the functional structure and species dominance of fern communities at the edge and in the interior of the forest. [ABSTRACT FROM AUTHOR]

Limestone substrates cover 20–30% of the continents and are the habitat of many calcareous fern species, which grow preferably or exclusively on this substrate. In this review, we resume the limestone properties and their implications for calcareous ferns. Additionally, we investigate the taxonomic distribution of limestone ferns by comparing five limestone regions and six mainly lithophytic genera to understand what proportion of ferns and which genera primarily colonise limestone in each region. Mexico is presented as a more detailed case study. Calcareous ferns have to deal with higher soil alkalinity, increased levels of Ca, Mg, and carbonates, lower P, Fe, and Zn availability, and often shallow, dry soils. Limestone ferns comprised 8-13% of the regional floras (except for South Africa) and were most diverse in Pteridaceae, Aspeniaceae, and Dryopteridaceae. However, the relative proportion of calcareous ferns in each of the six genera varied from region to region. The highest proportions of limestone species were detected in Ctenitis (73% in Jamaica), Adiantum and Asplenium (50% in Thailand), Anemia (40% in Jamaica), and Polystichum (35% in Jamaica and 33% in China). These results indicate a regionally independent evolution of limestone specialisation in ferns. Gypsum and serpentine ferns have to cope with even more extreme substrate conditions, are even rarer and may have evolved from limestone ferns. [ABSTRACT FROM AUTHOR]

The South America Dry Diagonal (SADD) is the most extensive and continuous portion of dry vegetation on the continent, characterised by lower rainfall and a marked dry season. Epiphytes are very poorly known and understudied in this area, even though they represent a high proportion of plant diversity in South America. Here, we compiled a dataset of epiphyte records from the SADD. The compiled epiphyte records date from 1859 to 2021, covering all four SADD domains, four countries, and 24 ecoregions. We utilised two databases for life form classification: Epilist and Brazil Flora Group. Our dataset contains 41,039 records distributed among 1119 epiphyte and hemiepiphyte species belonging to three main groups: angiosperms, ferns, and lycophytes. The SADD domains host a high number of unique species in each domain, with the Cerrado and Caatinga regions serving as primary hosts for the majority of species in the SADD dataset. Despite notable differences in species composition among domains, the least significant differences were observed between the Caatinga and Cerrado, as well as between the Chaco and the Pantanal. Orchidaceae, Bromeliaceae, and Polypodiaceae families exhibited the highest species diversity within the region. However, the species containing the highest number of specimens collected varied considerably among the domains. Herein, we also outlined some inconsistencies in the life-form classification across taxonomic bases, acknowledging the challenges of categorising epiphyte species while considering their intraspecific life-form variation. [ABSTRACT FROM AUTHOR]

Aim: Globally, biodiversity is unevenly distributed, as a result of varying environmental conditions and regionally different historical processes. The influence of the latter on current diversity patterns is poorly understood. We explore geographic patterns of matches and mismatches between phylogenetic relatedness metrics measuring different depths of evolutionary history and investigate the effects of evolutionary legacy at different evolutionary depths on species density of ferns. Methods: We divided the globe into 392 geographic regions on land, and collated species lists of ferns for each geographic region. We related species richness to phylogenetic metrics reflecting different depths of evolutionary history (standardized effect sizes of mean nearest taxon distance and mean pairwise distance, MNTDses and MPDses, respectively) for ferns in regional floras across the world. Location: Global. Time Period: Current. Taxon: Ferns. Results: We show that different centers of fern diversity have strikingly different phylogenetic composition. We find that overall fern species diversity is negatively correlated with both MNTDses and MPDses, so that regions with high species diversity tend to have clustered species assemblages, whereas species‐poor regions tend to have overdispersed species assemblages. At the global extent, MNTDses and MPDses together explained 62.2%, 19.3%, and 65.7% of the variation in species diversity for all ferns as a whole, non‐polypod ferns, and polypods, respectively. Main Conclusions: Our study suggests that current geographic patterns of fern species richness are driven, at least in part, by evolutionary history of ferns, which varies among biogeographic regions. [ABSTRACT FROM AUTHOR]

The role of large frugivores in the dispersal of tropical trees has been well‐studied, whereas the importance of the world's largest rodents for plant dispersal has previously been ignored. We studied plant dispersal by gut passage (endozoochory) in Neotropical wetlands by the largest extant rodent, the capybara Hydrochoerus hydrochaeris. We compared it with another of the world's 10 largest rodents, the nutria or coypu Myocastor coypus.We collected 96 faecal samples (50 capybara, 46 nutria) from 10 sites within the Taim Ramsar site in southern Brazil, and extracted intact propagules from 10 g subsamples. Propagules from 27 plant taxa (24 angiosperms, and three aquatic ferns) were recovered, representing 13 plant families. Whole Spirodela (duckweed) plants were dispersed. Seeds from 14 angiosperm taxa were germinated in the laboratory.Taxonomic composition of propagules was significantly different for the two mammals, but propagule size was not. Capybara dispersed more terrestrial propagules per sample, and nutrias more aquatic propagules. When total faecal production was taken into account, an estimated 1025 propagules (including 133 fern spores) were dispersed by each capybara per day, compared with 691 propagules for nutrias (including 566 fern spores). Capybaras have larger home ranges and likely dispersed plants over a greater distance.Synthesis: This is the first demonstration that rodents disperse aquatic pteridophytes as well as flowering plants. Our results suggest that capybaras and nutrias play important, complementary roles in dispersing a variety of aquatic and terrestrial plant species within Neotropical wetlands. Our study indicates that the role of herbivorous mammals as vectors of plants with small seeds and non‐fleshy fruits has been overlooked in the neotropics and that defaunation of large herbivores can have negative consequences, in a manner similar to that previously highlighted for frugivores. [ABSTRACT FROM AUTHOR]

We present an overview of the morphology, biogeography, and ecology of the fern genus Osmunda (i.e. without previously included taxa of Claytosmunda , Osmundastrum , and Plenasium), with a focus on the American O. spectabilis Willd. and Old World O. regalis L. While genetic data supports the separation of these taxa, commonly used morphologic characters to distinguish between O. regalis and O. spectabilis (maximum frond size; pinnae sessile vs. stalked; pinnules opposite vs. alternate; general pinnule proportions) are not infallible. We recorded morphometric differences among and between O. regalis and O. spectabilis and correlated these with spatio-environmental gradients. Our work provides an updated taxonomic overview with full synonymy and diagnostic key of Osmunda. We preliminarily recognize six informal subtaxa in O. regalis ('regalis', 'abyssinica', 'huegeliana', 'longifolia', 'transvaalensis', 'obtusifolia') and three in O. spectabilis ('spectabilis', 'palustris', 'piresii') that separate in a morphological traits-based principal component analysis. The morphotaxa appeared geographically structured and their distribution showed significant correlations with elevation, mean annual precipitation, annual mean temperature, and temperature seasonality. The taxonomic rank and validity of the proposed subtaxa has to be tested through a large-scale sampling, e.g. with comparative cp/nr genomic and cytogenetic analyses. Such future analyses may help to ascertain whether the observed morphologic peculiarities are conditioned solely by abiotic factors (which would allow addressing them as forms) or are manifested in the genome. [ABSTRACT FROM AUTHOR]

Fractals are important to explore the objects of our natural environment, such as mountains, trees, ferns, plants, lightning, rainbows, and snowflakes. Therefore, taking motivation from recent research about a new iteration scheme that converges more quickly than other popular hybrid iterative methods, we apply it to study the escape criterion. Using this criterion, we establish three algorithms. These algorithms are used to generate the important classes of fractals. Moreover, we present the analysis of how the fractal image changes with variations in different input parameters using proposed algorithms. More specifically, the complex function ℷ (z) = z m + b where m ≥ 2 , b ∈ ℂ is considered for the proof and application of the results. Also, we calculate the image generation time by considering different values of the involved parameters. Fascinating J-sets (i.e., Julia sets), M-sets (i.e., Mandelbrot sets), and multicorns (i.e., Mandelbrot sets of conjugate complex polynomial functions) at different values of m can be visualized. The successful application of a novel iteration scheme highlights the significance of this research over the existing one. [ABSTRACT FROM AUTHOR]

The Late Viséan (mid-Mississippian) anatomically preserved flora from Pettycur, Fife, Scotland is one of the most significant plant assemblages (lagerstätte) from this period anywhere in the world. It has been known from the later 19th century, mainly from loose limestone blocks found on the beach. Thin sections of limestones showing outstanding permineralised plants offered a number of the most eminent British palaeobotanists of their day to describe many of the plants. Most of the thin sections were made commercially so that an understanding of the formation of the deposit as a whole proved difficult. The peel technique developed in the 1950s allowed large slices of limestone to be peeled but only small pieces of the peels were ever mounted and studied by the new authors. Large collections (more than 100) of loose blocks on the beach and from in situ from within basaltic lava flows by the author and colleagues from the late 1970s onwards have been slabbed and peeled and provide the opportunity for new studies and an assessment of the plant assemblages and possible communities present. At least 25 plant organ species are present representing more than 13 whole plant species. Of particular significance is the occurrence of the four main lycopsid tree types that dominate later Pennsylvanian peats and the occurrence of five ferns. It is shown also that a number of the plants may also be preserved as charcoal, especially zygopterid ferns such as Metaclepsydropsis. Of particular importance is the occurrence of true permineralised peats that provide evidence of the botanical composition of the earliest peat-forming mire at a time of rapid global change with a sudden fall of atmospheric CO 2 and rise in O 2 that would have also had an effect upon wildfire systems. [ABSTRACT FROM AUTHOR]

Ferns are vascular plants with significant ornamental value, and in recent years, they have also been considered for the potential application in different economic sectors like nutrition, medicine and cosmetics. This study aimed to obtain in vitro fern gametophytes and sporophytes and evaluate their potential as secondary metabolites sources. For this study four fern species were used: Polypodium vulgare L. (PV), Asplenium trichomanes L. (AT), Athyrium filix-femina L. Roth (AF), and Osmunda regalis L. (OR). The polyphenols, flavonoids, tannins and terpenoids content and antioxidant activity were estimated by different colorimetric methods. For metabolite identification and their antioxidant activity, HP-TLC separations were used. Also, quantitative HPLC–DAD analysis was performed to estimate the content of certain metabolites. The results showed that in vitro generation of gametophytes registered higher growth rates in OR, PV, and AF, while the regeneration of sporophytes was better for PV, AT, and AF. The OR gametophyte produced the highest quantities in all analyzed metabolite classes and also had the highest antioxidant values. We report for the first time the presence of metabolites such as catechin, caffeic acid, gallic acid, ferulic acid, cinnamic acid, or rutin in OR. In this study, we demonstrated the possibility of producing potent antioxidant metabolites by in vitro cultures in ferns. [ABSTRACT FROM AUTHOR]

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The Ophioglossaceae family, one of the oldest orders of extant ferns, exhibits diverse morphological and chromosomal characteristics. This study presents the first complete plastome sequence of thermal adder's-tongue fern (Ophioglossum thermale), a species renowned for its antioxidant properties in traditional Chinese medicine. Our analyses revealed 27 simple sequence repeats (SSRs) in the plastome, with variations in SSR frequencies compared to related genera. Our phylogenetic analyses placed O. thermale within the Ophioglossum s.s. clade, supporting previous studies and suggesting polyphyly within the genus Ophioglossum based on the sensu PPG I system. The enlarged noncoding regions in fern organelles (ENRFOs) resulting from foreign DNA insertions in O. thermale were identified in the ycf2-trnH and trnT-trnfM regions, similar to other Ophioglossum species. ENRFOs were found at the LSC and SSC, but not in IRs in Ophioglossaceae. Consequently, foreign DNA insertions and lineage-specific SSRs shed light on plastome evolution in the Ophioglossaceae family. [ABSTRACT FROM AUTHOR]

[Objective] The study aims to elucidate the characteristics and cytological mechanisms of fertilization in the evolutionary special group of fern Lygodium japonicum . [Methods] Using embedding and electron microscopy techniques, ultrastructural observation was performed on the stage of sperm entry into the egg, nuclear fusion, egg expansion, and zygote polarity establishment during the fertilization process of L. japonicum . [Results] L. japonicum didn􀆳t have the typical egg envelope and fertilization pore, and spermatozoa penetrated the egg through the pore region. The first spermatozoon entered the cytoplasm of the egg, and 2-6 spermatozoa could also pass through the pore region to enter the fertilization cavity below the pore region of the egg, but could not fuse with the egg cytoplasm. After sperm entered the egg, the fertilized egg shrinked markedly to prevent the entry of other sperms, and a membrane structure was formed at the pore region above the fertilization cavity, blocking the entry of other sperms into the fertilization cavity. Nuclear fusion was initiated 30 min after spermatozoa entered the egg cell. The nucleus of spermatozoa was initially concentrated at one end of the nucleus and gradually penetrated into the nucleus of the egg, and nuclear fusion continued as the fertilized egg were expanding. Around 10 h after fertilization, the zygote produced a large number of vesicles, which first established vertical polarity and then changed to horizontal polarity, and underwent the first division of the zygote. [Conclusion] When L. japonicum undergoes fertilization, spermatozoa enters from the pore region and produces a fertilization cavity, similar to the core leptosporangiatae.

[Objective] The objective of this study is to investigate species diversity and floristic geographical characteristics, in order to provide a reference for the research on the diversity conservation, resource application and development, and phylogenetic evolution of lycophytes and fern in the Tingjiangyuan Nature Reserve. [Methods] On the basis of field investigation and specimen identification, combined with the literature data, the list of lycophytes and fern in the area was compiled, and the faunal composition and geographical composition were analyzed. [Results] (1) There were 129 species of lycophytes and ferns in 60 genera and 23 families, including 15 species of lycophytes in 5 genera and 2 families, and 114 species of ferns in 55 genera and 21 families. (2) The dominant families and genera were obvious, with 3 families and 1 genus of the dominant families. Monospecific families, genera, and oligogenes were the main bodies of the lycophytes and fern families and genera in the area. (3) The distribution types of families were mainly global and tropical, and the distribution types of genera and species were mainly tropical and temperate. There were 15 endemic species in China. (4) The geographical kinship between this area and the Liangye Mountain Nature Reserve was the closest. [Conclusion] The geographical composition of the lycophytes and fern plants in the Tingjiangyuan National Nature Reserve is diverse, with obvious endemic phenomena and low biodiversity. The plant flora shows a transition from tropical to temperate on a horizontal gradient.

Plant specialized metabolism has a complex evolutionary history. Some aspects are conserved across the green lineage, but many metabolites are unique to certain lineages. The network of specialized metabolism continuously diversified, simplified or reshaped during the evolution of streptophytes. Many routes of pan-plant specialized metabolism are involved in plant defence. Biotic interactions are recalled as major drivers of lineage-specific metabolomic diversification. However, the consequences of this diversity of specialized metabolism in the context of plant terrestrialization and land plant diversification into the major lineages of bryophytes, lycophytes, ferns, gymnosperms and angiosperms remain only little explored. Overall, this hampers conclusions on the evolutionary scenarios that shaped specialized metabolism. Recent efforts have brought forth new streptophyte model systems, an increase in genetically accessible species from distinct major plant lineages, and new functional data from a diversity of land plants on specialized metabolic pathways. In this review, we will integrate the recent data on the evolution of the plant immune system with the molecular data of specialized metabolism and its recognition. Based on this we will provide a contextual framework of the pan-plant specialized metabolism, the evolutionary aspects that shape it and the impact on adaptation to the terrestrial environment. This article is part of the theme issue 'The evolution of plant metabolism'. [ABSTRACT FROM AUTHOR]

Ferns native to Korea, such as Davallia mariesii, Dicranopteris pedata, and Gleichenia japonica, possess antioxidant and antibacterial properties. However, their inhibitory effects on skin photoaging have not been demonstrated. Measurement and comparison of the antioxidant activity of three types of ferns revealed that the extract from G. japonica had the best effect. This study evaluates the potential of G. japonica extract as a new functional material for preventing skin damage caused by ultraviolet radiation. G. japonica extracts showed protective effects against ultraviolet B (UVB) radiation in human epidermal keratinocyte cells; the extracts inhibited intracellular reactive oxygen species production. In addition, collagen biosynthesis increased, and matrix metalloproteinase-1 activity and protein expression level decreased in human primary dermal fibroblast irradiated with UVB. The main peak (compound 1) of the extract was separated through high-performance liquid chromatography analysis and preparative liquid chromatography. Compound 1 is strongly inferred to be the main active ingredient because it showed better antioxidant activity and UVB protection effect than G. japonica extract. These results demonstrate the physiological effects of G. japonica extract and suggest its applicability as a new functional substance for preventing skin damage caused by ultraviolet radiation.

Species identification and phylogenetic relationship clarification are fundamental goals in species delimitation. However, these tasks pose challenges when based on morphologies, geographic distribution, and genomic data. Previously, two species of the fern genus Bolbitis, B. × multipinna and B. longiaurita were described based on morphological traits; they are phylogenetically intertwined with B. sinensis and fail to form monophyletic groups. To address the unclear phylogenetic relationships within the B. sinensis species complex, RAD sequencing was performed on 65 individuals from five populations. Our integrated analysis of phylogenetic trees, neighbor nets, and genetic structures indicate that the B. sinensis species complex should not be considered as separate species. Moreover, our findings reveal differences in the degree of genetic differentiation among the five populations, ranging from low to moderate, which might be influenced by geographical distance and gene flow. The Fst values also confirmed that genetic differentiation intensifies with increasing geographic distance. Collectively, this study clarifies the complex phylogenetic relationships within the B. sinensis species complex, elucidates the genetic diversity and differentiation across the studied populations, and offers valuable genetic insights that contribute to the broader study of evolutionary relationships and population genetics within the Bolbitis species. [ABSTRACT FROM AUTHOR]

Cliffs contain one of the least known plant communities, which has been overlooked in biodiversity assessments due to the inherent inaccessibility. Our study adopted the unmanned aerial vehicle (UAV) with the telephoto camera to remotely clarify floristic variability across unreachable cliffs. Studied cliffs comprised 17 coastal and 13 inland cliffs in Gageodo of South Korea, among which 9 and 5 cliffs were grazed by the introduced cliff-dwelling goats. The UAV telephotography showed 154 and 166 plant species from coastal and inland cliffs, respectively. Inland cliffs contained more vascular plant species (P < 0.001), increased proportions of fern and woody species (P < 0.05), and decreased proportion of herbaceous species (P < 0.001) than coastal cliffs. It was also found that coastal and inland cliffs differed in the species composition (P < 0.001) rather than taxonomic beta diversity (P = 0.29). Furthermore, grazed coastal cliffs featured the elevated proportions of alien and annual herb species than ungrazed coastal cliffs (P < 0.05). This suggests that coastal cliffs might not be totally immune to grazing if the introduced herbivores are able to access cliff microhabitats; therefore, such anthropogenic introduction of cliff-dwelling herbivores should be excluded to conserve the native cliff plant communities. [ABSTRACT FROM AUTHOR]

Introduction: Several studies of MADS-box transcription factors in flowering plants have been conducted, and these studies have indicated that they have conserved functions in floral organ development; MIKC-type MADS-box genes has been proved to be expanded in ferns, however, few systematic studies of these transcription factors have been conducted in non-seed plants. Although ferns and seed plants are sister groups, they exhibit substantial morphological differences. Methods: Here, we clarified the evolution of MADS-box genes across 71 extant fern species using available transcriptome, genome, and gene expression data. Results: We obtained a total of 2,512 MADS-box sequences, ranging from 9 to 89 per species. The most recent common ancestor (MRCA) of ferns contained approximately three type I genes and at least 5-6 type II MADS-box genes. The domains, motifs, expression of type I and type II proteins, and the structure of the both type genes were conserved in ferns as to other land plants. Within type II genes, MIKC*-type proteins are involved in gametophyte development in ferns; MIKCC-type proteins have broader expression patterns in ferns than in seed plants, and these protein sequences are likely conserved in extant seed plants and ferns because of their diverse roles in diploid sporophyte development. More than 90% of MADS-box genes are type II genes, and MIKCC genes, especially CRM1 and CRM6-like genes, have undergone a large expansion in leptosporangiate ferns; the diverse expression patterns of these genes might be related to the fuctional diversification and increased complexity of the plant body plan. Tandem duplication of CRM1 and CRM6-like genes has contributed to the expansion of MIKCC genes. Conclusion or Discussion: This study provides new insights into the diversity, evolution, and functions of MADS-box genes in extant ferns. [ABSTRACT FROM AUTHOR]

Background and Aims Structural colour is responsible for the remarkable metallic blue colour seen in the leaves of several plants. Species belonging to only ten genera have been investigated to date, revealing four photonic structures responsible for structurally coloured leaves. One of these is the helicoidal cell wall, known to create structural colour in the leaf cells of five taxa. Here we investigate a broad selection of land plants to understand the phylogenetic distribution of this photonic structure in leaves. Methods We identified helicoidal structures in the leaf epidermal cells of 19 species using transmission electron microscopy. Pitch measurements of the helicoids were compared with the reflectance spectra of circularly polarized light from the cells to confirm the structure–colour relationship. Results By incorporating species examined with a polarizing filter, our results increase the number of taxa with photonic helicoidal cell walls to species belonging to at least 35 genera. These include 19 monocot genera, from the orders Asparagales (Orchidaceae) and Poales (Cyperaceae, Eriocaulaceae, Rapateaceae) and 16 fern genera, from the orders Marattiales (Marattiaceae), Schizaeales (Anemiaceae) and Polypodiales (Blechnaceae, Dryopteridaceae, Lomariopsidaceae, Polypodiaceae, Pteridaceae, Tectariaceae). Conclusions Our investigation adds considerably to the recorded diversity of plants with structurally coloured leaves. The iterative evolution of photonic helicoidal walls has resulted in a broad phylogenetic distribution, centred on ferns and monocots. We speculate that the primary function of the helicoidal wall is to provide strength and support, so structural colour could have evolved as a potentially beneficial chance function of this structure. [ABSTRACT FROM AUTHOR]

Background and Aims Niche differentiation is a crucial issue in speciation. Although it has a well-known role in adaptive processes of hybrid angiosperms, it is less understood in hybrid ferns. Here, we investigate whether an intermediate ecological niche of a fern hybrid is a novel adaptation that provides insights into fern hybrid speciation. Methods Pteris fauriei (Pteridaceae) is a natural hybrid fern, occurring in environments between its parent species. The maternal Pteris minor is found in sunny areas, but the habitat of the paternal Pteris latipinna is shady. We combined data from morphology, leaf anatomy and photosynthetic traits to explore adaptation and differentiation, along with measuring the environmental features of their niches. We also performed experiments in a common garden to understand ecological plasticity. Key Results The hybrid P. fauriei was intermediate between the parent species in stomatal density, leaf anatomical features and photosynthetic characteristics in both natural habitats and a common garden. Interestingly, the maternal P. minor showed significant environmental plasticity and was more similar to the hybrid P. fauriei in the common garden, suggesting that the maternal species experiences stress in its natural habitats but thrives in environments similar to those of the hybrid. Conclusions Based on the similar niche preferences of the hybrid and parents, we propose hybrid superiority. Our results indicate that the hybrid P. fauriei exhibits greater fitness and can compete with and occupy the initial niches of the maternal P. minor. Consequently, we suggest that the maternal P. minor has experienced a niche shift, elucidating the pattern of niche differentiation in this hybrid group. These findings offer a potential explanation for the frequent occurrence of hybridization in ferns and provide new insights into fern hybrid speciation, enhancing our understanding of fern diversity. [ABSTRACT FROM AUTHOR]

Resource allocation theory posits that organisms distribute limited resources across functions to maximize their overall fitness. In plants, the allocation of resources among maintenance, reproduction, and growth influences short‐term economics and long‐term evolutionary processes, especially during resource scarcity. The evolution of specialized structures to divide labor between reproduction and growth can create a feedback loop where selection can act on individual organs, further increasing specializaton and resource allocation. Ferns exhibit diverse reproductive strategies, including dimorphism, where leaves can either be sterile (only for photosynthesis) or fertile (for spore dispersal). This dimorphism is similar to processes in seed plants (e.g., the production of fertile flowers and sterile leaves), and presents an opportunity to investigate divergent resource allocation between reproductive and vegetative functions in specialized organs. Here, we conducted anatomical and hydraulic analyses on Onoclea sensibilis L., a widespread dimorphic fern species, to reveal significant structural and hydraulic divergences between fertile and sterile leaves. Fertile fronds invest less in hydraulic architecture, with nearly 1.5 times fewer water‐conducting cells and a nearly 0.5 times less drought‐resistant xylem compared to sterile fronds. This comes at the increased relative investment in structural support, which may help facilitate spore dispersal. These findings suggest that specialization in ferns—in the form of reproductive dimorphism—can enable independent selection pressures on each leaf type, potentially optimizing spore dispersal in fertile fronds and photosynthetic efficiency in sterile fronds. Overall, our study sheds light on the evolutionary implications of functional specialization and highlights the importance of reproductive strategies in shaping plant fitness and evolution. [ABSTRACT FROM AUTHOR]

The restriction of plant‐symbiont dinitrogen fixation by an insect semiochemical had not been previously described. Here we report on a glycosylated triketide δ‐lactone from Nephrotoma cornicina crane flies, cornicinine, that causes chlorosis in the floating‐fern symbioses from the genus Azolla. Only the glycosylated trans‐A form of chemically synthesized cornicinine was active: 500 nM cornicinine in the growth medium turned all cyanobacterial filaments from Nostoc azollae inside the host leaf‐cavities into akinetes typically secreting CTB‐bacteriocins. Cornicinine further inhibited akinete germination in Azolla sporelings, precluding re‐establishment of the symbiosis during sexual reproduction. It did not impact development of the plant Arabidopsis thaliana or several free‐living cyanobacteria from the genera Anabaena or Nostoc but affected the fern host without cyanobiont. Fern‐host mRNA sequencing from isolated leaf cavities confirmed high NH4‐assimilation and proanthocyanidin biosynthesis in this trichome‐rich tissue. After cornicinine treatment, it revealed activation of Cullin‐RING ubiquitin‐ligase‐pathways, known to mediate metabolite signaling and plant elicitation consistent with the chlorosis phenotype, and increased JA‐oxidase, sulfate transport and exosome formation. The work begins to uncover molecular mechanisms of cyanobiont differentiation in a seed‐free plant symbiosis important for wetland ecology or circular crop‐production today, that once caused massive CO2 draw‐down during the Eocene geological past. Summary Statement: The glycosylated triketide δ‐lactone cornicinine from crane flies elicited and maintained cyanobiont akinete differentiation in mosquito fern symbioses sharing the wetland habitat; it revealed processes of cell‐differentiation in ecologically significant N2‐fixing symbioses with cyanobacteria. [ABSTRACT FROM AUTHOR]

A new hybrid distributed to the south of the Colombian Andes is described in the genus Parablechnum. Morphological relationship with the parents and with other similar species is discussed. This is the first Parablechnum hybrid recorded in the Neotropical region. [ABSTRACT FROM AUTHOR]

Pronephrium s.l. (Thelypteridaceae) has its highest species diversity in Malesia. The distributional range and conservation status for many species have not been evaluated. Members of Pronephrium have been repeatedly collected from different parts of Peninsular Malaysia, nevertheless, their distribution has never been updated since Holttum's account in 1955, and the conservation status of the species reported from Peninsular Malaysia has never been assessed. Considering this, we provide an up-to-date account of the distribution and evaluate the conservation status of all the species reported for Peninsular Malaysia. The evaluation was based on five years of field observation and reviewing all herbarium collections. The conservation status of all species in the current study was assessed at a sub-national level confined to Peninsular Malaysia. Assesments were conducted based on IUCN Conservation Criteria and Categories. Two species were categorised as threatened, one species assessed as Endangered, one as Vulnerable, two as Near Threatened and four as Least Concern. One variety is endemic in Peninsular Malaysia. Various threats to the extant populations are identified and discussed. [ABSTRACT FROM AUTHOR]

The latest research shows that ferns and lycophytes have distinct evolutionary lineages. The codon usage patterns of lycophytes and ferns have not yet been documented. To investigate the gene expression profiles across various plant lineages with respect to codon usage, analyze the disparities and determinants of gene evolution in primitive plant species, and identify appropriate exogenous gene expression platforms, the whole-genome sequences of four distinct species were retrieved from the NCBI database. The findings indicated that Ceratopteris richardii, Adiantum capillus-veneris, and Selaginella moellendorffii exhibited an elevated A/U content in their codon base composition and a tendency to end with A/U. Additionally, S. capillus-veneris had more C/G in its codons and a tendency to end with C/G. The ENC values derived from both ENC-plot and ENC-ratio analyses deviated significantly from the standard curves, suggesting that the codon usage preferences of these four species were primarily influenced by genetic mutations and natural selection, with natural selection exerting a more prominent influence. This finding was further supported by PR2-Plot, neutrality plot analysis, and COA. A combination of RSCU and ENC values was used as a reference criterion to rank the codons and further identify the optimal codons. The study identified 24 high-frequency codons in C. richardii, A. capillus-veneris, and Diphasiastrum complanatum, with no shared optimal codons among the four species. Arabidopsis thaliana and Ginkgo biloba exhibited similar codon preferences to the three species, except for S. moellendorffii. This research offers a theoretical framework at the genomic codon level for investigating the phylogenetic relationships between lycophytes and ferns, shedding light on gene codon optimization and its implications for genetic engineering in breeding. [ABSTRACT FROM AUTHOR]

Premise: Bracken (Pteridium, Dennstaedtiaceae) is a cosmopolitan genus of aggressive disturbance colonizers that are toxic to agricultural livestock. The taxonomy of Pteridium has been treated in multiple schemes, ranging from one to six species worldwide, with numerous subspecies and varieties. Recent work has focused on the worldwide distribution and systematics of the bracken fern, but South America has been poorly represented. We present the first continent‐wide sampling and analysis of Pteridium esculentum, a Southern Hemisphere diploid species. Methods: Within South America, P. esculentum has several morphotypes, distinguished into subspecies by variation in indument and lamina architecture. We used double digest restriction site‐associated DNA sequencing (ddRADSeq) to assess the phylogenetic relationships of P. esculentum subspecies. Results: We found a striking genetic homogeneity in the species, being able to support only two morphotypes from molecular data: P. e. arachnoideum and P. e. campestre. We had high confidence for shallow and deep phylogenetic relationships, but less support for relationships among crown groups. Conclusions: We describe an east‐west geographic pattern that would explain the relationships between populations; and, in contrast to previous studies, we detected differences with P. esculentum from Australia. These results will lay the foundations for studying variations in this species' behavior as a weed, as well as its impact on the production of agricultural livestock in South America. [ABSTRACT FROM AUTHOR]

Premise: Vertical surfaces in urban environments represent a potential expansion of niche space for lithophytic fern species. There are, however, few records of differential success rates of fern species in urban environments. Methods: The occurrence rates of 16 lithophytic fern species native to the northeastern USA in 14 biomes, including four urban environments differentiated by percentage of impervious surfaces, were evaluated. In addition, the natural macroclimatic ranges of these species were analyzed to test whether significant differences existed in climatic tolerance between species that occur in urban environments and species that do not. Results: Three species appear to preferentially occur in urban environments, two species may facultatively occur in urban environments, and the remaining 11 species preferentially occur in nondeveloped rural environments. The natural range of fern species that occur in urban environments had higher summer temperatures than the range of species that do not, whereas other macroclimatic variables, notably winter temperatures and precipitation, were less important or insignificant. Conclusions: Vertical surfaces in urban environments may represent novel niche space for some native lithophytic fern species in northeastern USA. However, success in this environment depends, in part, on tolerance of the urban heat island effect, especially heating of impervious surfaces in summer. [ABSTRACT FROM AUTHOR]

Stomatal anatomy and behaviour are key to managing gas exchange fluxes, which require coordination with the plant vascular system to adequately supply leaves with water. Stomatal response times and regulation of water loss are generally understudied in ferns, especially across habits (i.e. epiphytic and terrestrial) and habitats (i.e. wet mesic and dry xeric environments). Our objectives were to (i) determine if hydraulic and anatomical traits that control water use are correlated with their habitats (i.e. xeric, mesic) and habits (i.e. epiphytic, terrestrial) for ferns and lycophytes across taxa, and (ii) explore how those traits and others like average leaf water residence time correlate with stomatal function using a subset of closely related species. Epiphytic species had lower vein densities than terrestrial species, while xeric species had higher vein densities than mesic species. Xeric ferns also had smaller stomata than mesic ferns but had similar stomatal densities. Further, in a subset of mesic and xeric ferns, the xeric ferns had higher maximum stomatal conductance and water content, as well as shorter average stomatal opening responses to light intensity, but stomatal closing times did not differ. Finally, shorter stomatal opening and closing responses were correlated with shorter water residence time. Our study highlights anatomical and physiological differences between ferns and lycophytes, which may partially explain habitat preference based on their optimization of light and water. [ABSTRACT FROM AUTHOR]

Phylogenetic analyses of planthoppers were conducted using a mitogenome dataset to examine the evolutionary relationships of current families based on both maximum likelihood (ML) and Bayesian inference methods. Delphacoidea, including Cixiidae and Delphacidae, and Fulgoroidea, including all other families, were consistently identified as monophyletic groups. However, Nogodinidae displayed a polyphyletic pattern, with various lineages emerging sister to several issidoid families. Variations were observed across different analyses in the positioning of (Dictyopharidae + Fulgoridae) and the relationships of Ricaniidae sister either to Issidae or to (Flatidae + Acanaloniidae). Several statistical tests indicate that the ML topology has the highest level of statistical confidence. The (Dictyopharidae + Fulgoridae) clade is best positioned as sister to (Derbidae + (Achilidae + (Tropiduchidae + other "higher" planthoppers families))) and the Ricaniidae as sister to (Flatidae + Acanaloniidae). With 13 fossil calibration points, origin times for Delphacoidea and Fulgoroidea were dated back to the Late Permian, approximately 257.46 million years ago. Delphacidae and Cixiidae split during the Late Triassic, while Fulgoroidea diversified earlier during the Middle Triassic. Divergence and diversification times are also provided for all other extant planthopper families. These results suggest that Delphacoidea and Fulgoroidea likely diverged from the older planthopper fossil families prior to the emergence of angiosperms and may have initially fed on gymnosperms and ancient ferns. The diversification of extant planthopper families occurred during the Jurassic and Cretaceous periods, influenced by evolving climatic conditions, the decline in gymnosperms, and the increasing diversity of angiosperm plants. [ABSTRACT FROM AUTHOR]

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As ancient organisms, tree ferns play a crucial role as an evolutionary bridge between lower and higher plant species, providing various utilitarian benefits. However, they face challenges such as overexploitation, climate change, adverse environmental conditions, and insect pests, resulting in conservation concerns. In this study, we provide an overview of metabolic and transcriptomic resources of leaves in two typical tree ferns, A. spinulosa and A. metteniana, and explore the resistance genes for the first time. The landscape of metabolome showed that the compound skimmin may hold medicinal significance. A total of 111 differentially accumulated metabolites (DAMs) were detected, with pathway enrichment analysis highlighting 14 significantly enriched pathways, including 2-oxocarboxylic acid metabolism possibly associated with environmental adaptations. A total of 14,639 differentially expressed genes (DEGs) were found, among which 606 were resistance (R) genes. We identified BAM1 as a significantly differentially expressed R gene, which is one of the core genes within the R gene interaction network. Both the maximum-likelihood phylogenetic tree and the PPI network revealed a close relationship between BAM1, FLS2, and TMK. Moreover, BAM1 showed a significant positive correlation with neochlorogenic acid and kaempferol-7-O-glucoside. These metabolites, known for their antioxidant and anti-inflammatory properties, likely play a crucial role in the defense response of tree ferns. This research provides valuable insights into the metabolic and transcriptomic differences between A. spinulosa and A. metteniana, enhancing our understanding of resistance genes in tree ferns. [ABSTRACT FROM AUTHOR]

Breakdown of chlorophyll (Chl), as studied in angiosperms, follows the pheophorbide a oxygenase/phyllobilin (PaO/PB) pathway, furnishing linear tetrapyrroles, named phyllobilins (PBs). In an investigation with fern leaves we have discovered iso‐phyllobilanones (iPBs) with an intriguingly rearranged and oxidized carbon skeleton. We report here a key second group of iPBs from the fern and on their structure analysis. Previously, these additional Chl‐catabolites escaped their characterization, since they exist in aqueous media as mixtures of equilibrating isomers. However, their chemical dehydration furnished stable iPB‐derivatives that allowed the delineation of the enigmatic structures and chemistry of the original natural catabolites. The structures of all fern‐iPBs reflect the early core steps of a PaO/PB‐type pathway and the PB‐to‐iPB carbon skeleton rearrangement. A striking further degradative chemical ring‐cleavage was observed, proposed to consume singlet molecular oxygen (1O2). Hence, Chl‐catabolites may play a novel active role in detoxifying cellular 1O2. The critical deviations from the PaO/PB pathway, found in the fern, reflect evolutionary developments of Chl‐breakdown in the green plants in the Paleozoic era. [ABSTRACT FROM AUTHOR]

Introduction: Ferns constitute the second largest group of vascular plants. Previous studies have shown that the diversity and composition of fern communities are influenced by resource availability and water stress, among other factors. However, little is known about the influence of these environmental factors on their biotic interactions, especially regarding the relationship between mycorrhizal fungi and ferns. The present study compares the mycorrhizal communities associated with 36 populations of Struthiopteris spicant L. Weiss across Europe and North America. This species exhibits a great tolerance to variations in light, nutrient, and pH conditions, and it can survive with and without mycorrhizae. Methods: With the aim of determining which environmental factors impact the composition and abundance of the root-associated fungal communities in this species, we used an ITS-focused metabarcoding approach to identify the mycorrhizal fungi present and analyzed the influence of climatic and edaphic variables at global and regional scales Results and discussion: We encountered striking differences in the relative abundance of arbuscular mycorrhizal fungi (AMF) between S. spicant populations at both spatial levels. We recorded a total of 902 fungal ASVs, but only 2– 4% of the total fungal diversity was observed in each individual, revealing that each fern had a unique fungal community. Light availability and the interactive action of pH and soil nitrogen concentration showed a positive influence on AMF relative abundance, explaining 89% of the variance. However, environmental factors could only explain 4– 8% of the variability in AMF community composition, indicating that it might be determined by stochastic processes. These results support the hypothesis that ferns may be more independent of mycorrhization than other plant groups and interact with fungi in a more opportunistic manner. [ABSTRACT FROM AUTHOR]

The population dynamics of rock fern Asplenium septentrionale in Estonia was monitored from 1994 to 2020; the data were analysed to understand how the rhythm of local weather variables affects the population condition and renewal. Both fern clump size and life stage (sporeling, premature, mature, senescent) structure of the population were studied. Our results indicate that the population has been stable, with a high proportion of reproductive adults. Precipitation distribution through all seasons of the year had a major impact on population recruitment. June was the key period of the year determining the survival of young sporelings. Higher rainfall in the previous year supported higher numbers of premature clumps in the following year. The number of mature fern clumps was most influenced by weather conditions during winter months and precipitation at the end of summer. The long-term survival of mature clumps might be threatened if periods without rainfall extend into the growing season and occur during consecutive years. Monitoring methods of nationally protected fern species should be improved by including individual-based observations on life stage transitions of young sporophytes (sporeling to premature, premature to mature) for predicting future trends in population conditions. [ABSTRACT FROM AUTHOR]

Class Mulgedio-Aconitetea comprises plant communities that develop primarily in the upper montane to subalpine vegetation belts. It is vegetation where tall herb species (forbs, ferns, grasses) occur dominantly; in the Balkans, it was studied only marginally. In this article, based on floristic composition we assess two questions: (1) what is the diversity of the class Mulgedio-Aconitetea in Bulgaria and (2) what environmental factors are responsible for the vegetation assemblages in the area? We analyzed 387 plots. We created an expert system that classifies this vegetation and tested environmental variables for their influence on these vegetation types. In total, 15 associations and one uncategorized community were classified using the Braun-Blanquet approach. The length of the growing season (number of growing degree days > 0 °C) and climate moisture have a significant effect on the vegetation. Disturbance severity, disturbance frequency and reaction have influence over the species scores. Moreover, all variables significantly differed between the vegetation types. [ABSTRACT FROM AUTHOR]

The exploration of the diversity of Lycophytes and Ferns of Valparai Range of Anamalai Tiger Reserve, Western Ghats, Tamil Nadu, Southern India resulted in the record for 10 Lycophytes and 93 Ferns of 18 Pteridophyte families. Based on the habitat-forms, there are 51 terrestrial, 15 epiphytes, 16 sciophytes 11 rheophytes and the rest mero- and xerophytes. Eleven out of 103 Pteridophytes showed a very narrow distribution. Among them, Alsophila nilgiriensis (Holttum) R.M.Tryon, Bolbitis semicordata (Baker) Ching, Diplazium travancoricum Bedd., Selaginella tenera (Hook. & Grev.) Spring and S. wightii Hieron. are endemics. Araiostegia hymenophylloides (Blume) Copel. is listed as endangered whereas Athyrium cumingianum (C.Presl) Milde, Bolbitis semicordata, Diplazium travancoricum and Huperzia phyllantha are considered globally threatened. Besides, Athyrium cumingianum (Athyriaceae) is an addition to the Pteridophyte flora of Tamil Nadu state. [ABSTRACT FROM AUTHOR]

The palynological composition of the Karoo-equivalent strata in the Tanga Basin, coastal Tanzania, is presented. Two boreholes (Kakindu-1 and Vunde-1) through the basin were palynostratigraphically studied. According to the findings, gymnosperm pollen and a few fern spores dominate the palynological assemblages. The absence of marine palynomorphs in the studied strata of the Tanga Basin attests to deposition in terrestrial environments, which is consistent with the common geologic reconstruction of the Karoo Supergroup across Africa. Two palynological intervals, the Klausipollenites schaubergeri and Jugasporites vellicoites, are recognized in the Kakindu-1 borehole; and two others, the Klausipollenites schaubergeri–Scheuringipollenites circularis and Alisporites minutosaccus–Faunipollenites gopadensis intervals, are identified in the Vunde-1 borehole. The present palynological data suggest the Permian to Triassic age for the Karoo strata in the Tanga Basin. The composition of the reported assemblage implies a single phytogeographic province across the Gondwana Supercontinent during the Permian to Triassic. Based on depositional ages determined herein, the Karoo strata in the Tanga Basin are correlated with second–fourth depositional sequences in the inland Karoo type-section of the Ruhuhu Basin of Tanzania, as well as to Ecca and Beaufort groups of the original Karoo type-section in South Africa. [ABSTRACT FROM AUTHOR]

We present the taxonomic treatment of Doryopteris from the states of Minas Gerais and Espírito Santo, Brazil, including some hybrids recognized for the first time in the literature. Fourteen species occur in the study area, plus three putative hybrids. Doryopteris × kollmannii, hybr. nov., is newly described; Doryopteris × angularis and Doryopteris × branneri were originally described as species, but have been lately considered as synonyms of D. rediviva and D. varians, respectively. Lectotypifications are proposed for D. raddiana var. patula, Litobrochia raddiana, Pteris collina, P. concolor, P. sagittifolia, and P. varians. We provide descriptions, illustrations, and taxonomic comments for all taxa. [ABSTRACT FROM AUTHOR]

As a result of the collection of ferns and lycophytes in the Huasteca potosina of Mexico, a new species of Adiantum is described and illustrated. Adiantum aquismonense has morphological and anatomical features that distinguish it from Adiantum tricholepis and Adiantum feei. In particular, A. aquismonense has reddish-brown hairs and its geographical distribution tends towards the slope of the Gulf of Mexico. In contrast, A. tricholepis has hyaline hairs, and while A. feei has reddish hairs similar in color to those of the new species, they are shorter. All three species are found in Mexico. Anatomically, the fusion of vascular bundles of the petiole in A. aquismonense occurs distally in the petiole, whereas in A. tricholepis it occurs in the middle of the petiole. The spongy parenchyma of the leaves is more compact in A. tricholepis than in A. aquismonense. [ABSTRACT FROM AUTHOR]

Sperm nuclear basic proteins (SNBPs) were isolated from extracted antheridia-rich male gametophytes raised from spores of the swordfern, Polystichum munitum. Electrophoretic (acetic acid-urea PAGE and SDS-PAGE) and chromatographic (rp-HPLC) characterization of the nuclear proteins exhibited the characteristics of the histone (H-type). In both types of gel electrophoresis, histones H1, H2A, and H2B showed an altered electrophoretic mobility corresponding to that which is routinely observed for the histones in other plants. Histones present during spermatogenesis of the fern P. munitum were compared with the few current SNBPs known to be present in higher and lower evolutionary plant clades. A transition from an early protamine (P-type) SNBPs in charophytes and bryophytes to the (H-type) SNBP observed here is reminiscent of similar reversions observed in the animal kingdom. [ABSTRACT FROM AUTHOR]

Plant–herbivore interactions reciprocally influence species' evolutionary trajectories. These interactions have led to many physical and chemical defenses across the plant kingdom. Some plants have even evolved indirect defense strategies to outsource their protection to ant bodyguards by bribing them with a sugary reward (nectar). Identifying the evolutionary processes underpinning these indirect defenses provide insight into the evolution of plant-animal interactions. Using a cross-kingdom, phylogenetic approach, we examined the convergent evolution of ant-guarding nectaries across ferns and flowering plants. Here, we discover that nectaries originated in ferns and flowering plants concurrently during the Cretaceous, coinciding with the rise of plant associations in ants. While nectaries in flowering plants evolved steadily through time, ferns showed a pronounced lag of nearly 100 My between their origin and subsequent diversification in the Cenozoic. Importantly, we find that as ferns transitioned from the forest floor into the canopy, they secondarily recruited ant bodyguards from existing ant-angiosperm relationships. Some plants use nectar to attract ant bodyguards. Here, the authors use a cross-kingdom phylogenetic approach to find that ferns and angiosperms evolved nectaries in the Cretaceous, coinciding with ant evolution, and that ferns recruited ant-bodyguards from existing ant-angiosperm partnerships. [ABSTRACT FROM AUTHOR]