Maria Beatriz Rossi Caruzo

An overview of recent taxonomic studies on Euphorbiaceae s.l. in Brazil

As Euphorbiaceae sensu lato distribuem-se especialmente nos tropicos, nos mais variados tipos de vegetacao e habitats, sendo uma das maiores, mais complexas e diversificadas familias das Angiospermas. Foi recentemente dividida em quatro familias e segundo os atuais sistemas de classificacao, baseados em estudos filogeneticos envolvendo dados moleculares, esta assim classificada: Euphorbiaceae sensu stricto, Phyllanthaceae, Putranjivaceae e Picrodendraceae, havendo uma proposicao de estabelecer Peraceae, taxon ainda em discussao. Houve tambem mudancas no posicionamento taxonomico de generos de ampla distribuicao no territorio brasileiro, tais como Amanoa, Drypetes, Pera, Phyllanthus, Podocalyx, Pogonophora e Richeria, entre outros. Alem disso, novas especies vem sendo propostas e a amplitude dos limites de distribuicao de diversos taxons vem aumentando no Brasil. Diante do exposto, os autores fornecem um panorama geral dos estudos mais recentes e avancos na taxonomia de Euphorbiaceae s.l. nas regioes Norte, Nordeste, Sudeste e Sul do pais, concentrando-se nos trabalhos de revisao e floras regionais, bem como nas mudancas que resultaram em nova configuracao taxonomica da familia.

Chemical composition and antimicrobial activity of the essential oil from Croton heterocalyx Baill. (Euphorbiaceae s.s.) leaves.

Abstract The chemical composition and the antimicrobial activity of the essential oil from Croton heterocalyx leaves were evaluated. The oil which was analyzed by GC and GC/MS was found to contain germacrene D (12.5%), bicycloger-macrene (11.2%), δ-elemene (9.2%) β-elemene (8.2%), spathulenol (6.9%), linalool (5.4%) and 1,8-cineole (3.7%) as major components. Croton heterocalyx oil displayed a high inhibitory activity against the fungi Aspergillus niger (16404) and Candida albicans (ATCC 10231) as well as the Gram-positive bacterium Staphylococcus aureus (ATCC 6538), but a very weak activity was observed for the Gram-negative bacteria Escherichia coli (ATCC 8739) and Pseudomonas aeruginosa (ATCC 9027).

Foliar secretory structures in Crotoneae (Euphorbiaceae): Diversity, anatomy, and evolutionary significance

PREMISE OF THE STUDY Phylogenetic and morphological studies have helped clarify the systematics of large and complex groups such as the tribe Crotoneae (Euphorbiaceae). However, very little is known about the diversity, structure, and function of anatomical features in this tribe. Crotoneae comprises the species-rich pantropical genus Croton and six small neotropical genera. Here we characterized the anatomy of leaf secretory structures in members of this tribe and explored their function and evolutionary significance. METHODS Young and mature leaves of 26 species were studied using standard anatomical light microscopy techniques. Three sections of Croton and one representative of Brasiliocroton and Astraea were sampled. KEY RESULTS We identified five types of secretory structures: laticifers, colleters, extrafloral nectaries, idioblasts, and secretory trichomes. Laticifers were present in all species studied except Croton alabamensis, which instead presented secretory parenchyma cells. Articulated laticifers are reported in Crotoneae for the first time. Colleters of the standard type were observed in the majority of the sampled taxa. Extrafloral nectaries were present in section Cleodora and in B. mamoninha, but absent in section Lamprocroton and Astraea lobata. Idioblasts were spread throughout the palisade and/or spongy parenchyma in most of the studied species. Secretory trichomes were restricted to Lamprocroton except for C. imbricatus. CONCLUSIONS This study revealed a high diversity of secretory structures, including novel ones, in one of the largest clades of Euphorbiaceae. Our results are promising for investigations on the anatomical and ecophysiological bases of species diversification within Euphorbiaceae.

Seed morphology in Euphorbia and its taxonomic applications: a case study in São Paulo, Brazil

Euphorbia L., with around 2000 species, is the biggest genus of Euphorbiaceae and one of the largest and most diverse genera within Angiosperms. It shows an almost cosmopolitan distribution and notable morphological diversity and is characterized by a pseudanthial inflorescence, the cyathium, which is unique to the genus. Along with its great morphological diversity in growth form, seed characters such as shape, testa ornamentation and presence or absence of caruncle are among its most notable and variable features. Given the potential utility of seed characters for species identification, we set to characterize the seeds from all known species (24) of Euphorbia occurring in the state of São Paulo, using photos and scanning electronic microscopy images. These species belong to three subgenera and seven sections of Euphorbia, and their morphological diversity is discussed in a phylogenetic context according to the most recent classification. Seed characters such as shape, size, testa ornamentation, and presence or absence of caruncle proved to be useful for identification of sections and for distinguishing closely related species.

Diversity of arborescent lineages of Crotoneae (Euphorbiaceae) in the Brazilian Atlantic Rain Forest

We conducted fieldwork and herbarium research to investigate the morphological diversity, taxonomy, and geographic distribution of arborescent lineages of tribe Crotoneae (Euphorbiaceae) in the Brazilian Atlantic Rain Forest domain, a neotropical region considered one of the world’s hot spots of biodiversity. We found that arborescent lineages of Crotoneae are represented in the Atlantic Rain Forest by two genera (Croton and Brasiliocroton) and 23 species. Of this total, 70% of the species are endemic to the Atlantic Rain Forest. The genus Brasiliocroton, which is endemic to Brazil, includes two species, and Croton is represented by 21 species. We provide identification keys, update morphological description of key characters, include pertinent taxonomic comments, and illustrate most of the studied species with live photographs to facilitate taxonomic identification. The conservation status of each species is also evaluated. We establish five new synonyms, one superfluous name, and nine lectotypifications.

Croton sapiifolius Müll.Arg. In: a new occurrence for the State of Espírito Santo, Brazil

ABSTRACT - ( Croton sapiifolius Mull.Arg.: a new occurrence for the State of Espirito Santo, Brazil). While studying Croton material collected in Espirito Santo, we found several specimens of Croton sapiifolius , a species previously restricted to the State of Bahia. The present paper updates our knowledge about the taxonomy, habitat and geographic distribution of C. sapiifolius . This finding increases the number of known Croton species occurring in Espirito Santo State to 20 and contributes to the knowledge of Croton of the Brazilian Atlantic Forest.Keywords: Atlantic Forest, Crotoneae, Flora, Restinga vegetationRESUMO - ( Croton sapiifolius Mull.Arg.: uma nova ocorrencia para o Estado do Espirito Santo, Brasil). Durante visita aos herbarios do Estado do Espirito Santo, foram encontrados especimes de C. sapiifolius para este Estado, uma especie conhecida ate o momento apenas para o Estado da Bahia. Neste trabalho sao apresentados dados atuais sobre a taxonomia e distribuicao geografica de

Sinopse da tribo Alchorneae (Euphorbiaceae) no Estado de São Paulo, Brasil

Two genera, Aparisthmium, a monotypic genus, and Alchornea, with three species, were recognized for the tribe Alchorneae in the State of Sao Paulo. Keys for genera and species, information about phenology, geographic distribution, vegetation of occurrence, and taxonomic comments are provided to each species.

Reassessment of Croton sect. Cleodora (Euphorbiaceae) Points to the Amazon Basin as Its Main Center of Diversity

Abstract Ongoing studies of Neotropical Euphorbiaceae have uncovered a surprising number of new species belonging to Croton L. sect. Cleodora (Klotzsch) Baill., one of the better studied clades in the genus. Here we describe six new species and reclassify three others that were either misplaced to section or regarded as species of unknown phylogenetic affinity in previous studies. The new species are all from South America, and five of them are restricted to the Amazon region. We update the most recent taxonomic revision of Croton sect. Cleodora by providing a new taxon list and an identification key for the 27 currently recognized species. Sixteen species occur in lowland forested areas of the Amazon basin. Our finding calls attention to the Neotropics, and the Amazon region in particular, where information about the flora and species geographic ranges is still incomplete, even for relatively well-studied plant groups.

A New Species of Croton Section Lamprocroton (Euphorbiaceae) from Southern Brazil

Abstract Croton longicarpus (Euphorbiaceae), a new species from southern Brazil, is here described and illustrated. The new species occurs in open vegetation and at the edges of Araucaria forest. The analysis of herbarium collections and observations from populations in the field indicate that the species has characters in common with members of Croton section Lamprocroton. The new species differs from other species in this section by its unusually elongated ovary and fruit, the narrowly spatulate sepals of the pistillate flowers, and long inflorescences.

Sinopse do gênero Acalypha L. (Euphorbiaceae) no Estado de São Paulo, Brasil

(Synopsis of the genus Acalypha L. (Euphorbiaceae) in the State of São Paulo, Brazil). Euphorbiaceae is one of the largest families of angiosperms, with 246 genera and approximately 6300 species distributed worldwide. Acalypha is the third largest genus of this family, including about 450 species and with a pantropical distribution. This work was based on the analysis of herbarium collections aiming to carry out the survey of species of the genus Acalypha in the State of São Paulo, as well as contribute to the knowledge of the family in the region and provide an identification key for the species of the genus. We recognized 14 species of Acalypha for São Paulo State, of which two represent new for the State records (A. herzogiana and A. velamea).