Phytogeographic Domains Research Articles

Floristic patterns among phytogeographical domains: unraveling the complexity of Brazilian transitions

Floristic patterns among phytogeographical domains: unraveling the complexity of Brazilian transitions

Overcoming biases of birds research in the Caatinga

“The biodiversity of the Caatinga is poorly known” has been a mantra among studies on biodiversity in Brazil, including birds. However, species richness in semiarid regions is expected to be lower than that in other ecosystems, and studies in the Caatinga have increased in recent decades. Therefore, this narrative may not only reflect knowledge bias. Here, we gathered complementary datasets of bird assemblages from literature and an online database of the Caatinga and other phytogeographic domains in Brazil. We then employed novel spatial and temporal predictive statistics to address this question. We estimate that the Caatinga is only six species short of fully knowing its taxonomic diversity. We did find important spatial knowledge gaps regarding species distribution, but only higher than that of the Atlantic Forest. The species richness and distribution of Caatinga birds are as well-known as the Pampa and Pantanal and are better known than the Cerrado and the Amazon rainforest. Our findings challenge the notion that the Caatinga is the poorest known region regarding birds. Bird research in the region should focus on advancing a research and conservation agenda that enhances understanding of regional biodiversity and ecosystem dynamics while promoting ecological syntheses for tropical dry forests.

Taxonomic studies in Wedelia (Asteraceae, Heliantheae) reveal a new species for the Brazilian Cerrado

Wedelia is the largest genus of Ecliptinae (Heliantheae, Asteraceae), comprising about 110 species. The Brazilian Cerrado is a highly threatened phytogeographic domain, which harbors the richest flora in the world among other savannas. A new subshrubby species of Wedelia was revealed occurring in the central part of Cerrado and is herein described as W. tenuinervia. This new species resembles W. foliacea in vegetative traits but differs mainly by having leaves with brochidodromous venation, pistillate ray flowers, glandular trichomes on the abaxial surface of the leaf blade, corolla lobes and apical anther appendages, phyllaries abaxial surface strigillose and disc cypselae 4–5-angled, keeled at the angles, without basal scars or elaiosomes, and carpopodium inconspicuous (vs. acrodromous venation, neuter ray flower, abaxial surface of the leaf blade, corolla lobes and apical anther appendage lacking glandular trichomes, phyllaries abaxial surface setose or glabrescent, and disc cypselae biconvex, not keeled, with basal scars or elaiosomes, and carpopodium in two plates or one shallowly lobed). Among the species with pistillate ray flowers, W. tenuinervia can be morphologically related to W. oligocephala, differing mainly by the membranaceous leaf blades with flat margins, brochidodromous venation, and solitary capitula (vs. subcoriaceous leaf blades with revolute margins, acrodromous venation and capitula in dichasia). Illustrations, comments, a preliminary conservation status, and the typification of W. foliacea’s synonyms are proposed.

Multiple aspects of tree beta diversity in coastal ecosystems in Brazil

AbstractAimPatterns of beta diversity reflect the formation dynamics of ecological communities. Here, we integrated geographic, phylogenetic, and phenotypic information of coastal woody vegetation to investigate (1) whether the observed dissimilarity between assemblages differs from that expected by chance, examining the roles of spatial and deterministic processes; (2) the relative contribution of beta‐diversity components (turnover and nestedness) for taxonomic, phylogenetic, and functional beta diversity; and (3) what environmental factors drive the differences in composition between assemblages for all these dimensions.LocationBrazil.TaxonAngiosperm trees.MethodsWe built dissimilarity matrices and partitioned the taxonomic, phylogenetic, and functional beta diversity from an incidence matrix, a phylogeny including the region's plants, and a matrix expressing functional distances. Using linear regressions, we tested the effects of different environmental predictors representative of the effects of water availability, thermal energy, habitat heterogeneity, edaphic constraints, climatic stability, and human influence on beta‐diversity patterns.ResultsTaxonomic, phylogenetic, and functional dissimilarities exhibited a typical pattern of greater dissimilarity with distance (i.e., as expected by chance). However, these patterns showed different contributions of beta‐diversity components, predominating turnover in taxonomic and phylogenetic dissimilarity, and nestedness in functional dissimilarity. Water availability had a slight effect on patterns of taxonomic and phylogenetic dissimilarities.Main conclusionsThe Brazilian coastal woody vegetation appears to have emerged through a dynamic of colonisation of evolutionarily distinct but functionally similar lineages that originated from adjacent phytogeographic domains, proportional to their diversity. This is consistent with a combination of both neutral and non‐neutral processes. Our findings underscore the complementary roles of different dimensions of beta diversity in explaining the dynamics of these vegetation communities.

Two New Arthoniales Species (Lichenized Ascomycota) From Brazil

Objective: The present work aimed to describe, comment, and illustrate two new lichenized species of Ascomycota. Method: Morphological analyses of the samples were performed at the Laboratory in the State University of Bahia (UNEB), Campus VIII. The lichen thalli were observed using a stereomicroscope (Zeiss); chemical treatments were performed to observe the microscopic structures of the lichens after exposure to 10% KOH (potassium hydroxide), lactophenol (cotton blue), Melzer’s reagent, chlorine, and viewed under UV light. The chemical compositions of the lichen were examined using thin layer chromatography (TLC) at the Biochemical Laboratory of the Federal University of Pernambuco. Results and conclusion: Stirtonia juaensis and Cryptothecia paramacrocephala are two new lichenized species of Ascomycota found colonizing the plants Spondias tuberosa Arruda (Umbuzeiro) and Piptadenia moniliformis Benth. (Quipembe) in the Caatinga phytogeographical domain near the village of Juá in the municipality of Paulo Afonso, within the Raso da Catarina Ecoregion in northern Bahia State, Brazil. Originality/value: Research related to lichen taxonomy in Brazil is still scarce, especially in the Caatinga. The new species of Stirtonia and Cryptothecia described and illustrated in this work expand the knowledge about fungi in Brazil.

Biogeography of restinga vegetation in Northern and Northeastern Brazil and their floristic relationships with adjacent ecosystems.

Restinga formations are defined as the vegetation covering sandy coastal sediments deposited during the Quaternary period, regardless their physiognomy. They are usually characterized as areas of confluence between plant species associated with diverse phytogeographical domains. However, detailed floristic and biogeographic studies are still required to better define their distribution patterns, the origins of their plant species, and their biogeographical affinities. In this study, we investigate the floristic similarities among restingas in Northern and Northeastern Brazil and diverse ecosystems from different Brazilian phytogeographical domains (Caatinga, Cerrado, Atlantic Forest and Amazonia). We employed multivariate analyses to investigate differences in species composition and identify floristically similar groups. While sharing species with other ecosystems, restingas exhibit unique floristic composition, representing a coastal flora. Furthermore, the restingas of Northern and Northeastern Brazil are biogeographically subdivided according to previously recognized sectors of the coast of the country. These findings underscore the complex nature of restinga ecosystems, influenced by environmental factors such as geographic distance, geology and climate. These insights contribute to a nuanced understanding of the complex relationships between restingas and their surrounding ecosystems, facilitating informed conservation efforts in the face of escalating urban and industrial expansion along the Brazilian coast.

Checklist e distribuição geográfica das espécies de Myrtaceae que ocorrem em campinaranas da Amazônia brasileira

ABSTRACT White-sand vegetation (campinarana) is a type of vegetation restricted to oligotrophic and highly leached white sand soils in the Amazon phytogeographic domain that includes grassland to forest phytophysiognomies. Campinaranas cover about 5% of this phytogeographic domain and are impacted by various anthropic activities that put plant species, especially endemic ones, at risk. Myrtaceae has significant representativeness in oligotrophic edaphic environments, but floristic and taxonomic studies on the family in campinaranas are still few and geographically limited. We present a checklist of Myrtaceae species known from campinaranas of the Brazilian Amazon based on the survey of herbarium specimens and literature data in order to assess the level of endemism of these species for this vegetation type. We compiled occurrence records of 72 species and six genera. Myrcia and Eugenia were the genera with the highest number of species. Overall, 38 species (53%) occurred only in the Amazon and two were endemic to campinaranas (Eugenia campina and Myrcia psammophila). Four species are new records for the Brazilian Amazon: Blepharocalyx salicifolius, Eugenia hatschbachii, Myrcia anceps and Myrcia racemosa. The specific richness of Myrtaceae in Brazilian campinaranas is likely to be underestimated since extensive areas, especially those farther from the riverbanks, in the states of Amazonas and Roraima, have not yet been intensively surveyed.

Floristic survey of vascular plants of the Parque Estadual da Pedra Selada, Rio de Janeiro, Brazil.

The Atlantic Forest is one of the most diverse and threatened phytogeographical domains in the world. Despite that, it includes regions with poor floristic knowledge, even in protected areas. Although the importance of protected areas in conserving the Atlantic Forest hotspot is undisputed, it is necessary to recognise the floristic richness of these areas to propose effective conservation actions. In this sense, online databases have proved to be a promising tool for compiling species lists with relevant biodiversity information. This study is based on the list of vascular plants of the "Parque Estadual da Pedra Selada", published in the "Catálogo de Plantas das Unidades de Conservação do Brasil". It summarises the species richness, endemism and conservation status of this protected area. The published list of vascular plants was based on data obtained from herbarium collections available in online databases. A total of 303 species have been recorded for the "Parque Estadual da Pedra Selada," of which 297 are native to Brazil, 78 are endemic to the Brazilian Atlantic Forest, and seven are endemic to the State of Rio de Janeiro. More than 60% of the species are woody, and more than 40% are trees. Eight threatened species (Endangered - EN and Vulnerable - VU), of which five are endemic to the State of Rio de Janeiro, are housed in this protected area. One species was classified as Data Deficient (DD). Our results increase the knowledge of the Atlantic Forest flora in the State of Rio de Janeiro and support effective conservation planning for this protected area.

Whole-plant and leaf determinants of growth rates in progenies of Genipa americana L. (Rubiaceae).

Genipa americana (Rubiaceae) is a fruit tree with broad phytogeographic domain and suitable for different silvicultural systems in the tropics. The knowledge associated with the relative growth rate of species such as G. americana, provides important guidelines for the effective establishment and survival of seedlings after planting in the field. In this study we investigated differences in growth, biomass allocation and photosynthesis of seedlings originating from different mother plants of G. americana in southern Bahia, Brazil. For this, we evaluated fifteen variables associated with carbon balance at the whole plant and leaf scales of twelve G. americana progenies. All seedlings grew over a period of 198 days under similar microclimatic conditions with approximately 65% full sun. Our results showed significant differences in the relative growth rates (RGR), with the highest and lowest mean values being 29.0 and 38.0 mg g-1 day-1, respectively. Differences in RGR between G. americana progenies were highly related to differences in biomass allocation at both whole plant and leaf scales. From a practical point of view, we demonstrate that the selection of mother plants to produce seedlings with higher growth rates, and consequently greater establishment capacity in field plantings, can be made from evaluations of growth and biomass allocation variables at the whole plant scale.

A comprehensive floristic knowledge of a fragment of Semideciduous Seasonal Forest [Parque Estadual da Serra da Concórdia], Rio de Janeiro, Brazil.

The "Serra da Concórdia" is part of the Atlantic Forest phytogeographical domain in the Brazilian state of Rio de Janeiro and it has a predominant phytophysiognomy of Semideciduous Seasonal Forest. This region underwent intense habitat loss and fragmentation during the 19th century, due to coffee plantations and later pastures. With the decline of these activities, the areas were abandoned, triggering secondary succession. In 2002, the "Parque Estadual da Serra da Concórdia" was established in this region to preserve the remaining forest fragments. The updated list of vascular plants recorded in this protected area, published in the "Catálogo de Plantas das Unidades de Conservação do Brasil", is presented here, along with information on richness, endemism, and conservation status. The "Parque Estadual da Serra da Concórdia" houses 231 vascular plant species, of which 90% are angiosperms, 10% ferns and lycophytes, and 27% endemic to the Atlantic Forest. Ten species are threatened with extinction, three are categorized as Endangered, and seven as Vulnerable. Although there have been expeditions in the "Parque Estadual da Serra da Concórdia", they have been limited, resulting in a low number of records and the species richness for a protected area. This is notable considering the 2,130 Brazilian native vascular plant species recorded in the semideciduous seasonal forest of Rio de Janeiro. Our data indicates that floristic inventories of Brazilian protected areas could help highlight gaps in flora knowledge and support the proposal of effective conservation actions.

Floristic inventory of Melastomataceae of the Iguaçu National Park, Paraná, Brazil

Abstract Melastomataceae is one of the richest families in Brazil, with 1,436 species, 158 occurring in the state of Paraná. Many of the species are pioneers and zoochoric, essential for regeneration and floristic composition of the Atlantic Forest, which is the phytogeographic domain covering the Iguaçu National Park (ParNa Iguaçu). We present the floristic inventory of Melastomataceae of ParNa Iguaçu. Three areas in the park were sampled from May 2019 to March 2020, where two are covered with Seasonal Semideciduous Forest (SSF), and the other in a transition between SSF and Mixed Ombrophilous Forest (MOF). Seventeen species of Melastomataceae in four genera were recorded: Miconia (14 spp.), Acisanthera, Chaetogastra, and Pleroma (with only one species each). Seven species occur in the two vegetation types in ParNa Iguaçu, while six occur only in MOF and four only in SSF. Of the 17 species, six are endemic to Brazil, four of which occur only in the south and southeast regions of the country. This study registers nine new records for the ParNa Iguaçu. Furthermore, the Miconia leaeichleri was collected for the first time in the western region of Paraná, which suggests the necessity for more collection efforts in the western region of the state.

Distribution and Endemism Areas of Bonamia Thouars (Convolvulacea) in Brazil.

Brazil harbors the highest richness of Convolvulaceae with 424 species recognized mainly distributed in the Amazon, Atlantic Forest, Caatinga and Cerrado phytogeographic domains. Seventeen of these species are representatives of Bonamia, with ten endemic to the country. The aim of the study was to map the distribution of this group to understand its richness, its sampling and detecting areas of endemism, valuable information for conservation. We collected data gathered from herbaria and from the online database. The data were refined (1) excluding of records not at the species level; (2) records with no identification of collection site or with only the identification of the state of collection. There was calculated the richness, the number of records and an estimate of richness per cell. We conducted a parsimony analysis of endemism for distribution analysis. Finally, the knowledge of richness for the species was analyzed. There were gathered 420 occurrence records, in 87 grid cells. Most grid cells observed in the study presented one species. Two endemic areas were found for the genus. The results contribute to the understanding of the distribution of the group in Brazil, highlighting shortfalls in collections.

Odonata (Insecta) en campos de gran altitud y ecosistemas asociados en la meseta de Poços de Caldas, Brasil

The High Altitude Fields (HAF) are unique phytosociological features that occur only in certain regions of the Atlantic Forest. It is composed of herbaceous and shrubby vegetation and shallow soils that promote local water infiltration and recharge. Occurring on top of hills, the HAF are isolated units in the landscape, connecting with the matrix through associated ecosystems (springs with riparian forests and “capões de mata”, which are natural islands of arboreal vegetation, commonly associated with rural vegetation, such as high-altitude fields, located above 1,200 m in phytogeographic domains of the Atlantic Forest, Cerrado or Caatinga). These areas have great species endemism, and studies concerning the order Odonata are still scarce. Thus, we aimed to evaluate the ecological responses (richness, diversity, specificity) of adult odonates in these ecosystems. The study was conducted from November 2020 to March 2021 in three areas in the Poços de Caldas Plateau, Minas Gerais state, Brazil. A total of 45 species (247 specimens) were collected, with the highest total richness being recorded for Anisoptera. Among the sampled areas, there was no difference in Anisoptera communities, but there was a difference in Zygoptera species composition. In general, the most preserved remnant of HAF, the greater it presents greater richness of Odonata and harbors a regional pool of species.

Fabaceae Lindl. in the Chapada do Araripe, Northeast Brazil

The Brazilian plateau known as Chapada do Araripe is home to several types of vegetation and a diversity of native species. This plateau is located among the Brazilian states of Ceará, Pernambuco, and Piauí, in the Northeast region. This study consisted of a floristic inventory of Fabaceae species prevailing in different environments of the mentioned plateau. Monthly botanical expeditions were performed from October 2021 to November 2022; these occurred at previously selected sites. The plant collection, herborization, and identification of the species were carried out according to the specialized literature, and the specimens were deposited in the Herbário Caririense Dárdano de Andrade-Lima (HCDAL). A total of 194 species, 11 infraspecific taxa, and 81 genera belonging to five subfamilies were listed. These numbers represented approximately 32% of the diversity of Fabaceae recorded in Brazil, and an increase of approximately 115% in the number of species previously recorded in the Chapada do Araripe. The most diverse subfamilies were Caesalpinioideae and Papilionoideae, with 90 and 89 species, respectively. The most representative genera were Senna (19 spp.), Chamaecrista (15 spp.), and Mimosa (14 spp.). Thirteen species and three varieties were new records in Ceará state. The predominant growth habit was tree type, recorded in 44% of the species (86), and the main habitats were Steppe Savannah, Savannah, and Wooded Steppe Savannah. Thirteen species are endemic to the Caatinga phytogeographic domain: Copaifera arenicola, Copaifera cearensis, Hymenaea cangaceira, Cenostigma microphyllum, Mimosa caesalpiniifolia, Mimosa misera, Parapiptadenia zehntneri, Pithecellobium diversifolium, Senna cearensis, Senna gardneri, Senna lechriosperma, Crotalaria holosericea e Luetzelburgia bahiensis. Regarding the status of species protection and conservation, most are in Least Concern status (48.8%), four are Near Threatened (Hymenaea cangaceira, Pterogyne nitens, Dalbergia cearensis, Parapiptadenia zehntneri), two species are in Vulnerable status (Melanoxylon brauna and Senegalia cearensis), one species did not have enough data for assessment (Copaifera cearensis), and one is Endangered (Amburana cearensis). The findings of the present study can support conservation strategies, and ecological and phytosociological studies, among others. Also, it can be used for planning and promoting environmental education. Such information is valuable for the conservation of biodiversity and sustainable management of natural resources of the Chapada do Araripe.

Biogeography and environmental preferences of Butia yatay (Mart.) Becc.

During the Quaternary, Chaco Phytogeographic Domain (Chaco) flora in subtropical South America experienced temperature and humidity fluctuations, primarily driven by wind dynamics, leading to significant shifts in species distribution. The palm Butia yatay is endemic to the Chaco and thrives in areas characterized by a warm-rainy climate and mostly restricted to sandy soils. To investigate the current geographic distribution of suitable habitat for B. yatay while assessing the significance of soil variables, we employed two distinct algorithms in species distribution modeling (SDM). We also determined whether the distribution of B. yatay has changed since the Pleistocene and whether these changes align with previously proposed Pleistocene refugia. In the present SDMs, we considered two separate sets of predictors, one set with bioclimatic variables only and the other set with bioclimatic topographic and soil variables. Additionally, we reconstructed the historical geographic distribution of suitable habitats using bioclimatic data. Our results suggested that the primary determinants of B. yatay's current distribution include precipitation and temperature of the driest month and soil cation exchange capacity. Incorporating soil variables affected the estimated size and range of suitable areas. Projections into the past indicated similar suitable habitat distributions during interglacial periods compared with the present. During the Last Glacial Maximum, climatically suitable habitat may have shifted northward, partially overlapping with previously suggested Pleistocene refugia located between the Paraná and Uruguay Rivers. These findings indicate the main factors driving the distribution and ecology of B. yatay and enhance understanding of subtropical flora shifts during the Quaternary. The approach also may prove valuable for other studies within the Chaco.

Isocarpha spathulata (Asteraceae: Eupatorieae, Ayapaninae): a New Species Registered in the Northeast of Brazil

Abstract— Isocarpha has five species distributed in North America, Mexico, the Caribbean, Central America, and South America. In Brazil, three species occur in the Caatinga and Cerrado phytogeographic domains. During the taxonomic treatment of the species from the Eupatorieae tribe, a new species of Isocarpha was discovered for the Northeast of Brazil, in the Caatinga domain. Isocarpha spathulata is distinguished from other species of the genus by an ovate to widely-ovate or ovate-rhombic leaf blade, a sessile to subsessile capitulum that is one to two mm long, a spathulate palea with a rounded apex, 36‐40 flowers, a persistent stylopodium, and an annuliform or inconspicuous carpopodium. Morphological description, illustration, distribution map, conservation status, and an identification key for Isocarpha taxa are presented herein.

The genus Malanea Aubl. (Rubiaceae) in the Atlantic Forest of Brazil

Background and aims – Malanea (Rubiaceae) is a Neotropical genus of ca 40 species, 15 of which occur in Brazil, with nine found in the Atlantic Forest domain. This study aims to present a taxonomic treatment of the species occurring in the Atlantic Forest domain. Material and methods – We studied collections deposited in 15 Brazilian herbaria, ALCB, BHCB, BHZB, CEPEC, HUEFS, HUFU, IPA, JPB, MAC, OUPR, PEUFR, RFA, RB, UFP, and UFRN, and collections in NY were studied online. Specimens were identified using protologues and digital images of types available online. Key results – Of the nine species of Malanea previously recognized in the Atlantic Forest domain, we accepted seven, six of which are endemic. Malanea macrophylla has a wide distribution also occurring in other Brazilian phytogeographic domains, and adjacent countries. We expanded the distribution of four species and identified Bahia as the possible centre of diversity for the group in the domain. In addition, an identification key to the species, detailed descriptions, taxonomic notes, typifications, illustrations, maps of geographic distribution, and assessments of conservation status are provided. The names Malanea evenosa, M. forsteronioides, M. macrophylla, M. martiana, and M. spicata are here typified. The calculated conservation status revealed three Endangered species, two Vulnerable ones, M. forsteronioides as Near Threatened, and M. macrophylla with a status of Least Concern.

Vanilla karenchristianae (Orchidaceae): taxonomic notes and first record in the Brazilian Atlantic Forest

Abstract: Background and Aims: Vanilla is one of the well-known genera of the family Orchidaceae due to the ornamental, medicinal and culinary attributes of some of its taxa. The genus is pantropical and has about 120 species mostly found in the Neotropics. The objective of this study was to report the occurrence of V. karenchristianae in the Brazilian Atlantic Forest. Methods: We present a morphological description of V. karenchristianae based on the analysis of the newly found population in the state of Bahía, Brazil, and the materials collected in other sites of the country and deposited in herbaria. Also, we provide taxonomical and habitat comments, photographs, and a distribution map of V. karenchristianae in Brazil. Key results: The present record represents the most eastern distribution of V. karenchristianae and is approximately 2380 kilometers far from the nearest locality where the species has been recorded. In Brazil, V. karenchristianae is currently known from the Amazon and Atlantic Forest phytogeographic domains and from only four localities, including the one added here. Conclusions: Further recording efforts are necessary to fully understand the geographical distribution and ecological requirements of V. karenchristianae.

Bryophytes from the Sítio do Rangedor State Park, Maranhão, Brazil

The Sítio Rangedor State Park is an important conservation unit in an urban area with remnants of Amazon Forest in different stages of succession. The Park presents a characteristic bryophyte flora and can be useful to evaluate the local environmental quality. The objective of this study was to survey the diversity, distribution and ecological aspects of bryophytes in this Conservation Unit. The specimens were collected on different substrates throughout the area during the rainy and the dry season. Sixteen species of bryophytes were recorded, 15 moss species and one liverwort species. Most taxa are widely distributed and well represented in all phytogeographic domains; only Garckea flexuosa (Griff.) Margad. & Nork. presented a rare distribution. Microcalpe subsimplex (Hedw.) W.R. Buck and Weisiopsis bahiensis (Müll. Hal.) Broth. are endemic to Brazil, and the latter is a new record for Maranhão. There was a predominance of life forms with high (tuft) and intermediate (mat and weft) tolerance to desiccation, as well as generalist species as to tolerance to light incidence. Information on global and national geographic distribution, functional groups and endemism is provided. The most abundant species was Hiophyla involuta. (Hook.) A. Jaeger. Acrocarpous growth predominated among mosses. Calymperes palisotii Schwägr. presented investment in resistant propagules, reflecting the highly seasonal climate of the region. The data provide a basis for future investigations and reinforce the need for greater efforts aimed at environmental education activities in the area. Further, the registration of rare and endemic reinforces the importance of the conservation of this area.

Understanding the “Marmeleiros”: a taxonomic treatment of Croton sect. Lasiogyne (Euphorbiaceae) in Brazil

We present here a taxonomic treatment of Croton sect. Lasiogyne occurring in Brazil. This study is based on field collections and analyses of more than 1,300 specimens held in 47 herbaria. Eleven species are recorded in Brazil, occurring in almost all phytogeographic domains (except the Pampa). Six species of those species are endemic to that country (Croton blanchetianus, C. claussenianus, C. compressus, C. jacobinensis, C. limae, and C. suassunae). The total absence of extrafloral nectaries and reduplicate-valvate sepals, or valvate sepals, are proposed here as morphological characteristics for the recognition of Brazilian species of the section Lasiogyne. The main characters used to differentiate the species are: branching pattern, stipule shape, venation, trichome type, shape of the sepals of the pistillate flower, shape and number of ramifications of the style, capsule shape, and seed surface texture. Croton macrocalyx is excluded here from this section and positioned in C. sect. Barhamia.