Abstract Caves are an ideal niche for photosynthetic microorganisms with the morphological and physiological adaptations to thrive under extreme conditions. Microclimatic conditions, mainly light, temperature, and relative humidity, vary depending on the location and configuration of these cavities. A systematic review with quantitative synthesis was conducted to identify which environmental and ecological factors favored the growth of algae and Cyanobacteriophyta in cave environments of the American continent. To this end, results of studies from 26 caves, corresponding to 10 countries of the American continent, were analyzed. The species number recorded was 358, of which Bacillariophyceae predominated, followed by Cyanobacteriophyta, Chlorophyta, Rhodophyta, Phaeophyceae, Dinoflagellata, and Glaucophyta. The Shannon index determined that the diversity derived from the compiled literature of algae and Cyanobacteriophyta that thrive in these environments was 4.94, which is remarkably high. Nitzschia and Navicula were the most diverse Bacillariophyceae genera, while Oscillatoria and Phormidium dominated among Cyanobacteriophyta, and for Chlorophyta, Chlorella and Scenedesmus were the most diverse. However, Rhodophyta, Phaeophyceae, Dinoflagellata, and Glaucophyta were less diverse. An exploratory principal component analysis suggests that algal and cyanobacterial thriving is determined more by humidity and cave type than by temperature and photosynthetically active radiation.
Abstract Contradictions were observed in a recent analysis of the ranges of two new Passiflora species described for Brazil, Passiflora itatiaiensis and P. pardifolia, raising questions concerning that author’s knowledge of the physical geography of Brazil and South America, as well as adherence to Brazilian legislation regulating the collection of plant specimens. Additionally, an examination of the material available in the herbarium collections cited for these species revealed a new record of P. itatiaiensis, expanding its known range.
Abstract The flora of the Cerrado is highly adaptable to climatic and edaphic variability, yet climate change and anthropogenic activities pose increasing challenges. Water is a vital resource for plant physiological and reproductive processes, and directly influences floral traits and pollinator visitation. Moreover, plant responses to fluctuations in water availability can similarly affect their ability to attract pollinators by altering floral attractants. The production and maintenance of flowers require considerable energetic investment, in addition to supporting critical physiological functions. This study assessed the water potential of Palicourea rigida inflorescences across different Cerrado phytophysiognomies and times of day, relating it to the frequency of floral visitors. The results revealed that water potential varied with environment and time and was positively correlated with visitation frequency, explaining up to 19.3 % of the variation in the number of floral visitors. These findings highlight the importance of water potential as a functional trait, especially in the context of increasing drought, with implications for reproductive success and the conservation of savanna flora. This factor should be taken into account in studies addressing functional traits in savanna ecosystems.
Abstract Microsatellite markers (SSR) are still largely used to assess the reproductive system and genetic diversity in plant populations. Although the timber tree Amburana cearensis (Fabaceae) is endangered, according to the IUCN classification, there are no effective management and conservation plans being implemented for the species. It occurs exclusively in South America, predominantly in Seasonally Dry Tropical Forests, such as Caatinga and Chaco, but also in savanna areas of the Cerrado. The negative effect of large human populations on the biodiversity of these regions is likely to be more pronounced for endangered species such as A. cearensis. We developed SSR markers, tested their transferability to Amburana-related genera, and described the genetic diversity of A. cearensis in Brazilian dry forests. The number of alleles per locus ranged from two to 11. Eight loci showed significant deviation from HWE. The genetic differentiation was low to moderate (F ST = 0.0972, p < 0.001), suggesting some gene flow among populations. Two loci were widely transferable to related genera. The developed SSR markers can be useful to study the reproductive biology and genetic diversity, and may therefore support more effective conservation strategies for A. cearensis by the inclusion of genetic information.
Abstract Cymodocea rotundata, a tropical seagrass abundant in Southeast Asia, exhibits considerable morphological plasticity. However, consistent morphological differences among populations may reflect genetic divergence potentially influenced by local environmental conditions, particularly in geographically isolated systems. We examined populations from two offshore Vietnam islands , Ly Son (more disturbed) and Phu Quy (less impacted), using morphological traits, biomass measurements, nuclear SSR markers, and chloroplast haplotypes (trnL-trnF). Morphological and biomass analyses revealed clear differences between islands: Phu Quy exhibited significantly longer and wider leaves, greater sheath length, and taller shoots, while Ly Son individuals had thicker rhizomes and higher below-ground biomass, suggesting phenotypic differentiation associated with contrasting environmental conditions. Although the SSR polymorphism was limited, the results indicated moderate differentiation and higher intra-population variability in Ly Son. Chloroplast sequencing of nine individuals identified four haplotypes, including both shared and island-specific lineages, with Ly Son exhibiting higher haplotype diversity. Together, these results support the recognition of Ly Son and Phu Quy as distinct conservation units. Overall, populations from both islands appear vulnerable to coastal development and environmental change, highlighting the need for site-specific conservation strategies to preserve their genetic and morphological diversity.
Abstract This study analyzes the leaf morphoanatomy of representatives of the Chapada Diamantina clade (Asteraceae, Eupatorieae) to identify anatomical characters that aid in the taxonomic delimitation of the group. Leaves from 16 species across six genera were examined, focusing on epidermis, mesophyll, vascular system, and trichomes. The results indicate adaptations to the Campo Rupestre environment, including a thick cuticle, high trichome density, stomatal crypts, and multiseriate parenchyma, suggesting a hypodermis of ground meristem origin and sclerenchyma sheath extensions. We scored 27 structural characters and mapped them onto the most recent phylogenetic tree recovered for the clade. The positioning of secretory ducts in the midrib may represent a synapomorphy of the clade. The presence of isobilateral mesophyll and sclerenchyma fibers in Agrianthus and Arrojadocharis reinforces their phylogenetic proximity. Semiria sp. nov. and Semiria viscosa share convergent anatomical traits, but key structural differences support their generic separation. Additionally, Bishopiella elegans is distinguished by homogeneous mesophyll and absence of mechanical support tissues, whereas Lasiolaena and Stylotrichium exhibit revolute margins and multistratified hypodermis. These findings highlight the relevance of leaf anatomy in taxonomic and evolutionary studies, supporting previous phylogenetic hypotheses and emphasizing the importance of integrating morphoanatomical and molecular data in the classification of Asteraceae.
Abstract The Myrtaceae is rich in phenolics and volatile terpenoids and has many reported associations with gall inducers in Brazilian restinga. These metabolites protect plants against both biotic and abiotic stresses, but also play a crucial signaling role in plant-herbivore interactions, especially on superhosts like Neomitranthes obscura. We hypothesize that the chemical identity of the superhosts relates to their capacity to respond to diverse galling herbivores, which was assessed through a two-step bibliographic survey resulting in 52 analysed documents. The prevalent classes of chemical compounds in the superhost Myrtaceae are hydrocarbonated (SH) and oxygenated sesquiterpenes (OS), which are related to plant identity and its interactions with the galling organisms. Among the superhost Myrtaceae, Neomitranthes obscura shares sesquiterpenic and phenolic derivatives with other host plants, which makes it impossible to infer why some species are superhosts while others are not. Our results suggest that a greater diversity of terpenoids may be related to metabolic flexibility, potentially increasing the ability of hosting galling species. However, further research is needed to explore this relationship, particularly in conjunction with other key metabolite classes in Myrtaceae, such as phenolic compounds.
Abstract Parablechnum is a genus in the fern family Blechnaceae that exhibits wide morphological variation without a distinct taxonomic discontinuity. To address this problem, we applied the technique of Elliptic Fourier Analysis to evaluate leaf shape by calculating Fourier harmonics based on coordinates derived from a closed outline. Using a combination of contour extraction software and the Momocs package in R, it was possible to analyze 102 specimens of Parablechnum using the pinna as the analytical component, due to its ease of visualization in digitized herbarium specimens. Among the six studied species, three distinct groups were identified using LDA and PCA, with one group consisting exclusively of Parablechnum cordatum. This analysis reaffirmed the segregation found in other studies, helped resolve the P. cordatum complex. This technique enables the use of digitally available herbarium materials, offering the possibility of identifying old specimens and evaluating taxonomic variation in cases like Parablechnum.
Abstract The traditional representation of the water cycle often overlooks the active role of vegetation in absorbing atmospheric moisture, rendering it incomplete. This oversight is particularly evident in the classic soil-plant-atmosphere continuum (SPAC), which describes a unidirectional water flow from soil to atmosphere. However, increasing evidence highlights reverse fluxes, such as the downward movement of water from the atmosphere to plants and potentially into the soil. One key mechanism enabling this is foliar water uptake (FWU), through which leaves directly absorb moisture from sources like fog, facilitating rapid hydration and internal redistribution of water. Despite growing documentation in eco-physiological research, FWU remains largely absent from broader scientific discourse, public policy, education, and ecosystem management frameworks. Neglecting FWU and fog as hydrological inputs limits our understanding of water dynamics in ecosystems, especially under climate change scenarios that alter fog and dew formation patterns. This viewpoint emphasizes the urgency of integrating FWU into ecological models, science education, and environmental decision-making. By rethinking the water cycle through this lens, we highlight a transformative pathway to enhance conservation strategies, understanding plant functional traits related to climate change, and the science-policy-society interface.
Abstract Understanding and conserving wetland vegetation requires a unified framework for classifying plants adapted to aquatic environments. Numerous taxonomic, limnological, and ecological studies have endeavored to establish such a framework. From Eugenius Warming's pioneering work to the latest classifications, this paper provides a historical overview of the various terms, concepts, and criteria used to categorize these plants, considering environmental factors, evolutionary relationships, and functional traits. The biological forms associated with adaptations to flooding, including floating and submerged species, offer valuable insights into the diverse life strategies of aquatic plants within the land-water continuum. This review thoroughly examines the definition of amphibious plants, a complex group that reflects the diversity of landscapes in which they occur, often resulting in sampling biases over time. These plants, reliant on water to complete their life cycle, are adapted to fluctuating water levels typical of waterway margins and exhibit phenotypic plasticity in response to varying degrees of soil water saturation. Finally, we discuss key considerations for sampling techniques to better investigate amphibious plants, such as sampling in different seasons and analyzing hydrological fluctuations in the studied region.
Abstract Despite the ecological importance of marine macroalgae, molecular studies on green and brown algae in Brazil remain limited in scope and continuity. This review presents a scientometric analysis of DNA sequences deposited in GenBank from 1998 to 2023, focusing on Brazilian specimens of Ulvophyceae and Phaeophyceae. We identified 304 sequences: 202 from Ulvophyceae and 102 from Phaeophyceae, produced by 17 institutions, with only six of these being Brazilian. The data reveal regional asymmetries, with most contributions concentrated in Southeastern and Northeastern regions of Brazil. Although more than 40 molecular markers have been employed, the most common were rbcL, tufA, and cox1. The absence of specimen voucher codes and incomplete metadata in many submissions highlights significant challenges in data quality and reproducibility. Compared to red algae (Rhodophyta), for which thousands of sequences exist, green and brown macroalgae remain understudied. Our findings underscore the urgent need to invest in researcher training, strengthen institutional collaboration, and improve the quality and sampling coverage of molecular data. Such actions are crucial for advancing the taxonomy, systematics, and conservation of Brazilian macroalgal biodiversity.
Abstract Mining activities in the Amazon result in significant environmental damage to mined areas. Natural regeneration through seed dispersal is a crucial process that aims to reintegrate those mined areas into the native vegetation nearby. In this study, our main objective was to compare seed and fruit dispersal strategies that occur in the vertical stratification in altered primary forest (APF) and natural regeneration (NR) areas after bauxite mining. The results indicate that zoochory was the most frequent dispersal syndrome in APF areas, with fleshy fruits being the most frequent. The NR areas exhibited greater variation in dispersal syndromes, with zoochory, anemochory, and autochory being the most representative, with a predominance of dry fruits. The differences in dispersal modes between APF and NR areas are within the patterns already expected and previously found in other studies on fruit dispersal. These findings emphasize that understanding how species composition and dispersal strategies are influenced by environmental and anthropogenic impacts is crucial for the restoration of these areas. This knowledge helps identify which dispersal mechanisms are best adapted to degraded areas, enabling more effective recovery strategies through planting species with similar dispersal mechanisms, particularly in regions impacted by mining.
Abstract Phyllanthaceae, with a pantropical distribution, has recently undergone significant changes in the composition of its genera. Among these, Phyllanthus is notable for its vast number of species, currently the second-largest genus in the family, and its remarkable morphological diversity. Brazil is home to approximately 100 Phyllanthus species, some of which exhibit a distinctive morphological adaptation: phylloclades, found in multiple taxonomic sections. With the establishment of a new section exclusive to the Brazilian Atlantic Forest, this study provides a comprehensive contribution, including morphological descriptions of the section and its three constituent species, a key for species identification, detailed illustrations, field photographs, and distribution maps. Additionally, it offers taxonomic notes and evaluates the conservation status of the species using the updated IUCN criteria.
The Northern Coast of Bahia state (NCB) encompasses the northernmost stretch of the state coastline and harbors restinga ecosystems of exceptional biodiversity, ecological, and cultural importance. Despite previous floristic surveys, non-arboreal restingas remain under-sampled, limiting the understanding of their composition and ecological dynamics. This study aimed to document angiosperm diversity in these habitats and assess the distinctiveness of their floristic communities. Field surveys were conducted in the non-arboreal restingas of Mata de S & atilde;o Jo & atilde;o and Entre Rios municipalities. Specimens were collected, photographed, and deposited at the ALCB Herbarium. Data from nine other Brazilian restingas were included in similarity (ANOSIM) and clustering (UPGMA) analyses using beta diversity indices. A total of 245 species, 174 genera, and 76 families were recorded, with Fabaceae (28 spp.), Rubiaceae (18 spp.), and Myrtaceae (16 spp.) being the most representative families. The genera Chamaecrista, Myrcia, and Cyperus were the most species-rich. While Bahia's floristic communities showed general similarity, the NCB restingas were markedly distinct from the southern coast, showing stronger affinities with Sergipe state restingas. This pattern suggests a phytogeographic block shaped by shared climatic and geomorphological conditions, as well as endemic species. Despite their richness, NCB's non-arboreal restingas remain insufficiently studied and increasingly threatened by rapid anthropogenic expansion.
The structure and function of fern galls are poorly studied, especially those occurring in poikilohydric ferns such as Pleopeltis minima (Polypodiaceae), which hosts globoid Cecidomyiidae galls on fronds. We expected that anatomical and histochemical features related to poikilohydry would be expressed in galls, potentially enhancing features that support gall inducer survival. We examined non-galled pinnae (NGP) and galled pinnae (GP) of P. minima from anatomical, histochemical, and histometrical perspectives. The NGP are covered on the abaxial surface by peltate scales with unlignified, pectin-thickened cell walls on the shield, which contain mucilage and polyphenols. The GP are covered by similar but larger scales on the adaxial and abaxial surfaces. This feature, potentiated in galls, is related to water absorption and reduction of water loss. The NGP mesophyll is dorsiventral, with parenchyma cells featuring thickened pectocellulosic walls. In galls, an outer storage tissue also has pectin-rich, thickened walls that also contain mucilage, increasing hydrophilic capacity. Nutritive cells surrounding the larval chamber accumulate metabolites that nourish the gall inducer, along with phenolics, which may mitigate free radical damage. Pleopeltis minima galls exhibit adaptations tied to poikilohydry, making them a valuable model for studying the physiological and biochemical aspects of galls in poikilohydric ferns.
Palynological studies provide valuable data for taxonomy, particularly in supporting species delimitation. The genus Stachytarpheta includes a smaller group of seven species with pedicellate flowers and salmon- or wine-colored corollas, which are restricted to the Brazilian Cerrado. Despite representatives of this group, known as the S. longispicata group, being readily distinguished from other Stachytarpheta taxa for bearing sessile flowers, differentiating the seven species remains challenging due to their pronounced morphological overlap. In this context, we analyze the pollen morphology of the seven species in the S. longispicata group, aiming to evaluate its relevance to current taxonomic circumscription. Palynological characterization was based on observations under light microscopy and scanning electron microscopy using pollen material from herbarium specimens of the seven species. Under light microscopy, we measured pollen grain parameters after chemically treating the samples. The pollen grains are monads, very large, radially symmetrical, isopolar, with an amb varying from triangular to quadrangular, and shape ranging from suboblate to prolate-spheroidal. Size, shape, sexine ornamentation, margin type, and membrane ornamentation were key to identification, supporting seven distinct species. We provide an identification key based on pollen morphology for the group.
Abstract: Historical woods express cultural relations around the use of biodiversity by human societies. This article presents an overview of woods used for cultural purposes in Brazil based on the epistemological concept of historical anatomy. Based on 64 publications between 1994 and 2025, this study maps the taxonomic diversity and categories of cultural use of wood, as well as the approaches and contributions to the field made by research groups and wood anatomists. The results show regional asymmetries, with a predominance of studies in the South and Southeast regions of the country and temporal gaps in the other regions. Furthermore, interest in the field has grown in recent years, contributing to a better understanding of the historical use of woods from Brazilian flora. A search was conducted for specialized literature in the main online databases that related historical woods to anatomical identification of the wood. A total of 164 species were recorded in 14 use categories, with emphasis on shelters/buildings, sacred statuary, and watercraft. The concentration of studies in a few states and the prevalence of some species indicate cultural patterns and structural limitations of national research. The work proposes guidelines to expand geographic and thematic coverage, strengthen research networks, and guide public policies aimed at valuing the cultural heritage of wood in Brazil.
Abstract Some plants synthesize phytotoxic compounds that can inhibit the development of neighboring species. Phenolic compounds from some botanical families have been the focus of studies because of their effect on surrounding plants. This work aims to analyze the phytochemical profile of leaf methanolic extracts through the identification of major phenolic compounds, evaluation of their phytotoxicity, and their intraspecific variation. Leaves from Calophyllum brasiliense, Psidium guineense, and Miconia cinnamomifolia from the Ombrophilous Forest and Restinga phytophysiognomies were sampled. The phytotoxic activity was also tested against Solanum lycopersicum. The extract of M. cinnamomifolia presented the greatest chemical diversity and intraspecific variation. The M. cinnamomifolia forest extract presented potent inhibition of seed germination and root growth of the target species. Both C. brasiliense extracts affected the target species in higher concentrations. In the P. guineense Restinga extract, which had greater activity than the species' forest extract, 8-hydroxyluteolin-8-sulfate was identified. This is the first report of flavonoid sulphate for the Myrtaceae family, with reported biological activities and indicated for studies in bioprospection. Our study highlights the importance of conservation of Atlantic Forest species, due to the diversity of phenolic compounds and their phytotoxic effects, in response to distinct environmental conditions.
Abstract Ecological restoration of grasslands is widely dependent on seed addition to reestablish native plants. Thus, it is important to know the seed ecology of native species. The South Brazilian grasslands are species-rich ecosystems seriously threatened by land use conversion and invasive species, which makes their restoration extremely urgent. Nevertheless, poor knowledge about the germination of native herbaceous species limits ecological restoration efforts. Here we present, based on a literature search, a synthesis of the knowledge on germination and seedling emergence of native herbaceous species from South Brazilian grasslands, identify knowledge gaps, and present directions to enhance research and its application in restoration. We found 907 tests performed on 127 native species, mostly conducted in a germination chamber, but with a wide variety of seed storage conditions, seed dormancy break treatments, and germination conditions during tests. Poaceae and Fabaceae are the most tested botanical families. We recommend (1) the inclusion of more species, also from more plant families, into testing, considering also a better coverage of different grassland regions in seed collecting; (2) publicizing and making test data openly accessible; (3) developing standardized protocols for seed collection, storage, and germination tests; and (4) increase testing of emergence under field conditions.
Abstract The diversity of plant species managed by Indigenous peoples is directly related to cultural and linguistic factors. Many species were domesticated to varying degrees in the lowlands of South America. However, there is still a need to better understand the process of species and landscape domestication, especially the management practices of the indigenous populations of inland Brazil, such as the speakers of the Jê language family. With this in mind, we undertook a systematic review of the literature on the plant species used by these peoples for food and medicinal purposes. We examined 126 publications, covering 126 years. A richness of 609 botanical species was identified. Some plants, such as maize, manioc, sweet potatoes, and yams, are managed by peoples across the northern, central, and southern regions, while others are managed exclusively by peoples from within the same linguistic branch or geographical area. The results reveal that the Jê maintain a high level of species diversity with varying degrees of domestication in their food production systems and that the biodiversity generated and managed by these indigenous populations is a key factor for agricultural resilience in a scenario of climatic extremes.
