Gynoecium structure in Sapindales and a case study of Trichilia pallens (Meliaceae).

Sapindales is a monophyletic order within the malvid clade of rosids. It represents an interesting group to address questions on floral structure and evolution due to a wide variation in reproductive traits. This review covers a detailed overview of gynoecium features, as well as a new structural study based on Trichilia pallens (Meliaceae), to provide characters to support systematic relationships and to recognize patterns of variations in gynoecium features in Sapindales. Several unique and shared characteristics are identified. Anacrostylous and basistylous carpels may have evolved multiple times in Sapindales, while ventrally bulging carpels are found in pseudomonomerous Anacardiaceae. Different from previous studies, similar gynoecium features, including degree of syncarpy, ontogenetic patterns, and PTTT structure, favors a closer phylogenetic proximity between Rutaceae and Simaroubaceae, or Rutaceae and Meliaceae. An apomorphic tendency for the order is that the floral apex is integrated in the syncarpous or apocarpous gynoecium, but with different length and shape among families. Nitrariaceae shares similar stigmatic features and PTTT structure with many Sapindaceae. As the current position of both families in Sapindales is uncertain, floral features should be investigated more extensively in future studies. Two different types of gynophore were identified in the order: either derived from intercalary growth below the gynoecium as a floral internode, or by extension of the base of the ovary locules as part of the gynoecium. Sapindales share a combination of gynoecial characters but variation is mostly caused by different degrees of development of the synascidiate part relative to the symplicate part of carpels, or the latter part is absent. Postgenital fusion of the upper part of the styles leads to a common stigma, while stylar lobes may be separate. Due to a wide variation in these features, a new terminology regarding fusion is proposed to describe the gynoecium of the order.

Amazon plant diversity revealed by a taxonomically verified species list.

Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.

Phylogeny of Schinus L. (Anacardiaceae) with a new infrageneric classification and insights into evolution of spinescence and floral traits.

Schinus, best known by its few cultivated and invasive species, is the largest genus of Anacardiaceae in southern South America. It is remarkably diverse compared to closely related genera, with approximately 42 species, most of which occur in several arid vegetation types and extend into Andean and Atlantic moist forests. The most comprehensive taxonomic revision of the genus dates to 1957, recognizing S. subg. Schinus and S. subg. Duvaua, the latter of which were further divided into two sections. Subsequent studies have highlighted morphological inconsistencies in this infrageneric classification, and species delimitation remains a challenge. Schinus has been poorly sampled in previous phylogenetic studies of Anacardiaceae, and thus any assumptions about its monophyly and relationships remain untested. We investigated the phylogenetic relationships of 44 Schinus taxa and sampled 122 specimens, including the outgroup, using nine nuclear and two plastid DNA sequence regions, most of them developed recently for Commiphora (Burseraceae, sister to Anacardiaceae). We used maximum parsimony, maximum likelihood, and Bayesian inference to infer relationships among species. We also constructed a morphological dataset, including vegetative anatomical features, and compared these characters to hypotheses based on molecular evidence in order to achieve a better understanding of the relationships among the species of Schinus and to related genera, aiming also to identify morphological characters and putative synapomorphies for major clades, and to discuss hypotheses regarding the evolution of structural traits in the genus. Our analyses strongly support the monophyly of Schinus, but also indicate that S. subg. Schinus and the sections of S. subg. Duvaua are polyphyletic. The phylogenetic relationships that emerged from our analyses include eight relatively well-supported lineages, but relationships among closely related species remain unclear in some clades. Ancestral state reconstructions demonstrate that several morphological and leaf-anatomical characters are valuable in characterizing some lineages. By contrast, most of the traits that have traditionally been used to circumscribe groups in Schinus show high levels of homoplasy. In light of these results, we present a novel sectional classification of Schinus based on a combination of character states associated with geographic distribution, corresponding to lineages that are mostly allopatric or at least ecologically distinct.

Testing the monophyly of Simaba (Simaroubaceae): Evidence from five molecular regions and morphology.

Generic circumscriptions in the mostly pantropical family Simaroubaceae are somewhat controversial. Simaba is the largest genus, currently defined as exclusively neotropical, with around 25 species of trees and shrubs, but both its limits and infrageneric classification have been a matter of discussion and divergence. Traditionally, species of the genus have been treated in three sections: Simaba sect. Tenuiflorae, S. sect. Floribundae and S. sect. Grandiflorae, but a phylogenetic analysis suggested that the latter two may not be monophyletic. To test the monophyly of Simaba and its infrageneric classification, we used a molecular approach based on DNA sequence data from two nuclear ribosomal spacer regions (ITS and ETS) and three plastid regions (rps16 intron, and intergenic spacers psbA-trnH and trnL-trnF), including a comprehensive sampling of species from Simaba and closely related genera. We also performed ancestral character reconstructions to identify morphological characters that could serve as synapomorphies for major clades and to explore patterns of homoplasy in the morphological dataset. Our results show Simaba as traditionally circumscribed is not monophyletic, with taxa segregated into two strongly supported but distinct clades, one of which is more closely related to Simarouba. The three main clades that emerged in the phylogeny include a mostly Amazonian Simaba clade (which includes the type species of Simaba and the remaining species of S. sect. Tenuiflorae, here proposed to be recognized as Simaba sensu stricto), a mostly extra-Amazonian Simaba clade (a distinct lineage that will be recognized as Homalolepis, a genus currently treated in synonymy and equivalent to Simaba sections Grandiflorae and Floribundae), and the Simarouba clade (including all of its current species). These three clades are characterized by a combination of morphological characters, described in detail herein, some of which are novel features for Simaba not previously reported in the literature. Mapping character-states on the phylogenetic tree provides tests for evolutionary hypotheses. For example, our reconstruction of habit and geographic distribution suggests that the diversification of several shrubby species within the extra-Amazonian lineage in the South American cerrados probably occurred from ancestors inhabiting tropical forests, involving transitions in morphological and ecological traits.

Phylogeny of Helieae (Gentianaceae): Resolving taxonomic chaos in a Neotropical clade.

The monophyletic and Neotropical tribe Helieae of the worldwide family Gentianaceae (Gentianales, Asterids, Angiospermae) is well known for its problematic generic classifications. An initial phylogenetic analysis of Helieae shed light onto the relationships between genera, and indicated that traditional generic limits did not correspond to monophyletic groups. In order to obtain a more thorough understanding of generic relationships within the group, we enhanced sampling within the so-called Symbolanthus clade and performed phylogenetic analyses from DNA sequences from one plastid region (matK) and two nuclear regions (ITS and 5S-NTS), plus 112 morphological characters, which were analyzed separately and in combination, using parsimony and Bayesian approaches. A total of 83 individuals representing 20 genera and 51 species of Helieae were sampled; 13 species were included in this study solely based on their morphological characters. Ancestral character reconstructions were performed to identify potential synapomorphies of clades and patterns of homoplasy in the morphological dataset. Our results demonstrate that Prepusa is sister to the remainder of Helieae. Furthermore, the Macrocarpaea clade, the Irlbachia clade and the Symbolanthus clade were also recovered. Within the Symbolanthus clade, our results confirm that Calolisianthus and Chelonanthus are not monophyletic, and also contest the monophyly of Irlbachia as currently circumscribed. Specifically, two species of Calolisianthus group with the type species of Chelonanthus, while the other Calolisianthus species are more closely related to Tetrapollinia and Symbolanthus. Moreover, the green-white-flowered Chelonanthus species and Adenolisianthus are undoubtedly related to Helia and several analyses support Irlbachia pratensis as more closely related to the lineage including the type species of Chelonanthus described above The addition of new characters and taxa led to higher confidence in the relative position of some clades, as well as provided further support for a new generic circumscription of Calolisianthus, Chelonanthus, and Helia. Even though several morphological characters traditionally used in the taxonomy of the group were shown to be homoplasious, most clades can be diagnosed by a combination of morphological character states.

Fusion within and between whorls of floral organs in Galipeinae (Rutaceae): structural features and evolutionary implications.

BACKGROUND AND AIMS: Most genera of the neotropical Galipeinae (tribe Galipeeae, Rutoideae) exhibit several forms and degrees of fusion between the floral organs, including the union of petals into an apparently sympetalous corolla, the joining of the stamens among themselves and to the corolla, and the partial to complete connation of carpels. Though these and others floral traits are currently used in the circumscription of species in Galipeinae, few studies have shown in detail in which way (postgenital or congenital) and to what extent these fusions occur. To elucidate these anatomical conditions, a structural study of the flowers of the Galipeinae species was carried out. METHODS: Flowers of six species from three genera of Galipeinae were studied in their morphology, anatomy and development with stereomicroscopy, light microscopy and scanning electron microscopy (SEM). KEY RESULTS: The floral tube is formed by synorganization of stamens with petals in all species, and exhibits three main patterns: (1) Conchocarpus heterophyllus and C. minutiflorus have a floral tube formed by marginal coherence/adherence of petals and filaments due to interwining trichomes (postgenital connection); (2) Erythrochiton brasiliensis has a tube formed by congenital fusion of petals and filaments; and (3) Galipea jasminiflora and Conchocarpus macrophyllus have a tube formed distally with the first pattern, and proximally with the second pattern. Although floral tubes seem to be homologous within Galipeinae, this is not true at the level of the family: the floral tube of Correa (from an only distantly related clade of the family) is formed by postgenital union of the petals representing a convergent structure. The gynoecium of the studied species of Galipeinae shows a great variability in the extent of fusion of carpel flanks. Even though different structures for the mature gynoecium were found in each genus, all genera show postgenitally fused carpel apices, which is related to the formation of a compitum, as described earlier for other members of Rutaceae. CONCLUSIONS: The degree and diversity of fusions of floral organs in Galipeinae is unique within the order Sapindales. A study of the amount of diversification of Galipeinae in South America and comparison with other clades of Rutaceae would be of interest.

Extremely low nucleotide diversity among thirty-six new chloroplast genome sequences from Aldama (Heliantheae, Asteraceae) and comparative chloroplast genomics analyses with closely related genera.

Aldama (Heliantheae, Asteraceae) is a diverse genus in the sunflower family. To date, nearly 200 Asteraceae chloroplast genomes have been sequenced, but the plastomes of Aldama remain undescribed. Plastomes in Asteraceae usually show little sequence divergence, consequently, our hypothesis is that species of Aldama will be overall conserved. In this study, we newly sequenced 36 plastomes of Aldama and of five species belonging to other Heliantheae genera selected as outgroups (i.e., Dimerostemma asperatum, Helianthus tuberosus, Iostephane heterophylla, Pappobolus lanatus var. lanatus, and Tithonia diversifolia). We analyzed the structure and gene content of the assembled plastomes and performed comparative analyses within Aldama and with other closely related genera. As expected, Aldama plastomes are very conserved, with the overall gene content and orientation being similar in all studied species. The length of the plastome is also consistent and the junction between regions usually contain the same genes and have similar lengths. A large ∼20 kb and a small ∼3 kb inversion were detected in the Large Single Copy (LSC) regions of all assembled plastomes, similarly to other Asteraceae species. The nucleotide diversity is very low, with only 1,509 variable sites in 127,466 bp (i.e., 1.18% of the sites in the alignment of 36 Aldama plastomes, with one of the IRs removed, is variable). Only one gene, rbcL, shows signatures of positive selection. The plastomes of the selected outgroups feature a similar gene content and structure compared to Aldama and also present the two inversions in the LSC region. Deletions of different lengths were observed in the gene ycf2. Multiple SSRs were identified for the sequenced Aldama and outgroups. The phylogenetic analysis shows that Aldama is not monophyletic due to the position of the Mexican species A. dentata. All Brazilian species form a strongly supported clade. Our results bring new understandings into the evolution and diversity of plastomes at the species level.

Alkaloids from stems of Esenbeckia leiocarpa Engl. (Rutaceae) as potential treatment for Alzheimer disease.

Esenbeckia leiocarpa Engl. (Rutaceae), popularly known as guarantã, goiabeira, is a native tree from Brazil. Bioactivity-guided fractionation of the ethanol stems extract afforded the isolation of six alkaloids: leiokinine A, leptomerine, kokusaginine, skimmianine, maculine and flindersiamine. All isolated compounds were tested for acetyl cholinesterase inhibition, in vitro and displayed anticholinesterasic activity. The alkaloid leptomerine showed the highest activity (IC50 = 2.5 mM), similar to that of the reference compound galanthamine (IC50 = 1.7 mM). The results showed for the first time the presence of alkaloids leptomerine and skimmianine in E. leiocarpa (Engl.) with potent anticholinesterasic activity.

First Phylogeny of Bitterbush Family, Picramniaceae (Picramniales).

Picramniaceae is the only member of Picramniales which is sister to the clade (Sapindales (Huerteales (Malvales, Brassicales))) in the rosidsmalvids. Not much is known about most aspects of their ecology, geography, and morphology. The family is restricted to American tropics. Picramniaceae representatives are rich in secondary metabolites; some species are known to be important for pharmaceutical purposes. Traditionally, Picramniaceae was classified as a subfamily of Simaroubaceae, but from 1995 on, it has been segregated containing two genera, Picramnia and Alvaradoa, with the recent addition of a third genus, Nothotalisia, described in 2011. Only a few species of the family have been the subject of DNA-related research, and fewer than half of the species have been included in morphological phylogenetic analyses. It is clear that Picramniaceae remains a largely under-researched plant group. Here we present the first molecular phylogenetic tree of the group, based on both chloroplast and nuclear markers, widely adopted in the plant DNA barcoding. The main findings are: The family and its genera are monophyletic and Picramnia is sister to two other genera; some clades corroborate previous assumptions of relationships made on a morphological or geographical basis, while most parts of the molecular topology suggest high levels of homoplasy in the morphological evolution of Picramnia.

Comprehensive untargeted metabolomics of Lychnnophorinae subtribe (Asteraceae: Vernonieae) in a phylogenetic context.

Members of the subtribe Lychnophorinae occur mostly within the Cerrado domain of the Brazilian Central Plateau. The relationships between its 11 genera, as well as between Lychnophorinae and other subtribes belonging to the tribe Vernonieae, have recently been investigated upon a phylogeny based on molecular and morphological data. We report the use of a comprehensive untargeted metabolomics approach, combining HPLC-MS and GC-MS data, followed by multivariate analyses aiming to assess the congruence between metabolomics data and the phylogenetic hypothesis, as well as its potential as a chemotaxonomic tool. We analyzed 78 species by UHPLC-MS and GC-MS in both positive and negative ionization modes. The metabolic profiles obtained for these species were treated in MetAlign and in MSClust and the matrices generated were used in SIMCA for hierarchical cluster analyses, principal component analyses and orthogonal partial least square discriminant analysis. The results showed that metabolomic analyses are mostly congruent with the phylogenetic hypothesis especially at lower taxonomic levels (Lychnophora or Eremanthus). Our results confirm that data generated using metabolomics provide evidence for chemotaxonomical studies, especially for phylogenetic inference of the Lychnophorinae subtribe and insight into the evolution of the secondary metabolites of this group.

speciesLink: rich data and novel tools for digital assessments of biodiversity / speciesLink: dados valiosos e ferramentas inovadoras para avaliações digitais da biodiversidade

Abstract speciesLink is a large-scale biodiversity information portal that exists thanks to a broad collaborative network of people and institutions. CRIA's involvement with the scientific community of Brazil and other countries is responsible for the significant results achieved, currently reaching more than 15 million primary biodiversity data records, 95% of which are associated with preserved specimens and about 25% with high-quality digital images. The network provides data on over 200,000 species, of which over 110,000 occur in Brazil. This article describes thematic networks within speciesLink, as well as some of the most useful tools developed. The importance and contributions of speciesLink are outlined, as are concerns about securing stable budgetary support for such biodiversity data e-infrastructures. Here we review the value of speciesLink as a major source of biodiversity information for research, education, informed decision-making, policy development, and bioeconomy.

Resumo speciesLink é um portal de informações em larga escala sobre biodiversidade, que existe graças a uma ampla rede colaborativa de pessoas e instituições. O envolvimento do CRIA com a comunidade científica do Brasil e de outros países é responsável pelos resultados expressivos alcançados, atingindo atualmente mais de 15 milhões de registros de dados primários de biodiversidade, sendo 95% associados a espécimes preservados e cerca de 25% a imagens digitais de alta qualidade. A rede fornece dados sobre mais de 200.000 espécies, das quais mais de 110.000 ocorrem no Brasil. Este artigo descreve as redes temáticas do speciesLink, bem como algumas das ferramentas mais úteis desenvolvidas. A importância e as contribuições do speciesLink são destacadas, assim como as preocupações em garantir um apoio financeiro estável para e-infraestruturas de dados sobre biodiversidade. Aqui revisamos o valor do speciesLink como uma das principais fontes de informação sobre biodiversidade para pesquisa, educação, tomada de decisão, desenvolvimento de políticas e bioeconomia.

Chilean Pitavia more closely related to Oceania and Old World Rutaceae than to Neotropical groups: evidence from two cpDNA non-coding regions, with a new subfamilial classification of the family.

The position of the plant genus Pitavia within an infrafamilial phylogeny of Rutaceae (rue, or orange family) was investigated with the use of two non-coding regions from cpDNA, the trnL-trnF region and the rps16 intron. The only species of the genus, Pitavia punctata Molina, is restricted to the temperate forests of the Coastal Cordillera of Central-Southern Chile and threatened by loss of habitat. The genus traditionally has been treated as part of tribe Zanthoxyleae (subfamily Rutoideae) where it constitutes the monogeneric tribe Pitaviinae. This tribe and genus are characterized by fruits of 1 to 4 fleshy drupelets, unlike the dehiscent fruits typical of the subfamily. Fifty-five taxa of Rutaceae, representing 53 genera (nearly one-third of those in the family) and all subfamilies, tribes, and almost all subtribes of the family were included. Parsimony and Bayesian inference were used to infer the phylogeny; six taxa of Meliaceae, Sapindaceae, and Simaroubaceae, all members of Sapindales, were also used as out-groups. Results from both analyses were congruent and showed Pitavia as sister to Flindersia and Lunasia, both genera with species scattered through Australia, Philippines, Moluccas, New Guinea and the Malayan region, and phylogenetically far from other Neotropical Rutaceae, such as the Galipeinae (Galipeeae, Rutoideae) and Pteleinae (Toddalieae, former Toddalioideae). Additionally, a new circumscription of the subfamilies of Rutaceae is presented and discussed. Only two subfamilies (both monophyletic) are recognized: Cneoroideae (including Dictyolomatoideae, Spathelioideae, Cneoraceae, and Ptaeroxylaceae) and Rutoideae (including not only traditional Rutoideae but also Aurantioideae, Flindersioideae, and Toddalioideae). As a consequence, Aurantioideae (Citrus and allies) is reduced to tribal rank as Aurantieae.

Checklist das Spermatophyta do Estado de São Paulo, Brasil / Checklist of Spermatophyta of the São Paulo State, Brazil

O projeto Flora Fanerogâmica do Estado de São Paulo tem se dedicado a inventariar a flora paulistana há quase 20 anos. Conta com a atuação de mais de 200 colaboradores, a maioria do próprio estado, além de pesquisadores de outros estados e do exterior. Desde 2001, foram publicados sete volumes com as monografias de 151 famílias, contendo 3.237 espécies em 722 gêneros. Este projeto foi o ponto de partida para o conhecimento da diversidade das espécies de espermatófitas do estado de São Paulo. A apresentação do checklist neste momento é oportuna por constituir a produção de uma listagem das espécies com identificações certificadas pelos especialistas, além de conter a referência de uma coleção de herbário para a maior parte dos táxons (material-testemunho) ou referência à bibliografia em que a espécie é citada como ocorrente, de forma nativa ou subespontânea, no estado. Dessa forma, é aqui apresentada a listagem das espermatófitas do estado de São Paulo, com 7.305 espécies, distribuídas em 1.776 gêneros e em 197 famílias (segundo Cronquist 1981) ou então 195 (segundo o APG III). Em relação à flora do Brasil, com 31.728 espécies de espermatófitas, o estado São Paulo compartilha de 23% dessas espécies. As famílias mais representativas são Orchidaceae (797 espécies), Asteraceae (676 espécies), Fabaceae (513 espécies), Poaceae (500 espécies), Myrtaceae (304), Rubiaceae (265 espécies) e Melastomataceae (253 espécies) que, juntas, somam 3.308 espécies e constituem mais de 45% do total de espécies de espermatófitas do estado. Considerando a grande diversidade vegetal brasileira, parcialmente expressa em um estado, depreende-se a grande importância da continuidade dos estudos florísticos no Brasil, país provavelmente detentor da maior diversidade vegetal do planeta.

The Phanerogamic Flora of São Paulo State project has been dedicated to create an inventory of the flora for 20 years. More than 200 collaborators are involved, mostly from the State of São Paulo, with the contributions of researchers from other states and from abroad. Since 2001, seven books with monographs of 151 families were published, dealing with 3,237 species within 722 genera. This project was the starting-point of the gathering of information about the diversity of spermatophytes of the State of São Paulo. The current checklist, at this point, presents an updated and virtually complete list of species, all certified by specialists. It also contains references to scientific collections for most of the taxa (vouchers) or to bibliography referring to the natural or subspontaneous occurrence of the species in the State. The list now contains 7,305 species distributed in 1,776 genera and in 197 spermatophyte families (according to Cronquist 1981) or 195 (according to APG III). 23% of the 31,728 species of spermatophytes listed in the Flora of Brazil occur in São Paulo State. The most representative families are Orchidaceae (797 species), Asteraceae (676 species), Fabaceae (513 species), Poaceae (500 species), Myrtaceae (304), Rubiaceae (265 species) and Melastomataceae (253 species), which, altogether, accumulate 3,308 species and constitute 45% of total species of spermatophytes in the state. The wealth of the Brazilian plant diversity, partially expressed in São Paulo, shows how important is the continuity of floristic studies in a country that is very likely to hold the largest plant diversity in the planet.

Revisão taxonômica de Croton sect. Lamprocroton (Müll. Arg.) Pax (Euphorbiaceae s.s.) / Taxonomic revision of Croton sect. Lamprocroton (Müll. Arg.) Pax (Euphorbiaceae s.s.)

Croton is the second bigger and more diverse genus in the family Euphorbiaceae, with about 1,200 species distributed in 40 sections, occurring in all tropical areas, most of them in Americas. In South America, Brazil is the country in which a larger number of taxa are found, ca. 356. According to recent classification, the genus belongs to the tribe Crotoneae, and despite the wide and morphological diversity, it would be a monophyletic taxon. However, a phylogenetic analysis using markers of ITS region from nuclear ribosomal DNA, and of trnL-F from plastidial DNA, showed that Croton, like traditionally circumscribed, is not a monophyletic taxon. A taxonomic revision of Croton section Lamprocroton (Müll. Arg.) Pax is presented here. It is a Neotropical group with most of its species occurring from Southeast and South Brazil to southern South America (Uruguay and Argentina). Morphologically, the members of Lamprocroton are characterized as monoecious or dioecious shrubs or subshrubs, with a lepidote indumentum at least in part of foliage, entire leaves with no glands. The staminate flowers have 9 to 16 stamens and the pistillate flowers may have equal or unequal sepals, reduced to absent petals, and styles once or twice bifid. Overall, are recognized 26 species in the group, three of them new to the science. Identification key, morphological descriptions, illustrations, phenological period, as well as data on geographic distribution and general comments of each species are presented. Four taxa were excluded from C. sect. Lamprocroton because they do not show the morphological features that are diagnostics of the section. Four species that are poorly known were not included in the taxonomic treatment.

O gênero Croton L. é o segundo maior e mais diverso da família Euphorbiaceae, possuindo cerca de 1.200 espécies, agrupadas em 40 seções, com distribuição pantropical, das quais a maioria ocorre nas Américas. Na América o Sul, o Brasil é o país que congrega o maior número de espécies, aproximadamente 356. De acordo com a mais recente classificação, o gênero pertence à tribo Crotoneae e, apesar do grande número de espécies e da grande diversidade morfológica, seria um táxon monofilético. Entretanto, uma análise filogenética recente, que utilizou dados moleculares das regiões ITS, do DNA nuclear ribossômico, e do fragmento trnL-F, do DNA plastidial, demonstrou que Croton, como tradicionalmente circunscrito, não é um táxon monofilético. Neste trabalho, é apresentada uma revisão taxonômica de Croton sect. Lamprocroton (Müll. Arg.) Pax. Trata-se de um grupo neotropical com a maioria das espécies ocorrendo nas regiões Sudeste e Sul do Brasil e sul da América do Sul. Seus representantes caracterizam-se por ser plantas arbustivas ou subarbustivas, monóicas ou dióicas, com indumento lepidoto presente em pelo menos parte da folhagem e folhas inteiras e sem glândulas. As flores estaminadas possuem androceu composto por 9 a 16 estames e as flores pistiladas apresentam sépalas iguais ou desiguais no tamanho, pétalas reduzidas ou ausentes e estiletes uma ou duas vezes bífidos. Neste trabalho são reconhecidas 26 espécies na seção sendo três novas para a ciência. Chave de identificação, descrições morfológicas, ilustrações, período fenológico, distribuição geográfica e comentários gerais de cada uma das espécies são apresentados. Quatro táxons foram excluídos de C. sect. Lamprocroton por não possuírem os caracteres morfológicos diagnósticos da seção. Quatro espécies não foram incluídas no tratamento taxonômico por falta de informação sobre as mesmas.