Roberto Lourenço Esteves

Palynotaxonomy of Vernonanthura H. Rob. (Vernonieae, Asteraceae) species from Southeast Brazil

The present work studied the pollinic characteristics of 22 species of Vernonanthura from Southeast Brazil. The pollen grains were acetolysed, measured, described and ilustrated under light, scanning and transmission electron microscopy. Based on the results, Vernonanthura was considered an euripolinic genus as pollen grains presented distinctive characteristics, mainly related to the ornamentation, the size and apertures of the pollen grains, which may serve as a further tool in the delimitation of the species.

Palinotaxonomia de espécies de Chrysolaena H. Rob., Echinocoryne H. Rob. e Stenocephalum Sch. Bip. (Vernonieae-Compositae) ocorrentes no sudeste do Brasil

A pollen study of 11 species distributed in three genera, Chrysolaena H. Rob., Echinocoryne H. Rob. and Stenocephalum Sch. Bip. belonging to the Vernoniinae subtribe was carried out to characterize the pollen of these species and evaluate their taxonomic position. The pollen grains were acetolysed, analyzed and illustrated using light microscopy. For further details of pollen surface and aperture, non-acetolysed pollen grains were analysed by means of scanning and transmition electron microscopy. The genera were separated by a pollen key in two major groups using organization and number of lacunae that form the lophate pattern. In the first group, Echinocoryne H. Rob. species have pollen grains with 30 lacunae and in a second group, Chrysolaena H. Rob. and Stenocephalum Sch. Bip. species with 29 lacunae. Echinocoryne H. Rob. species are palynologically homogenous and only Echinocoryne holosericea (Mart. ex DC.) H. Rob. and Echinocoryne schwenkiaefolia (Mart. ex DC.) H. Rob. can be separated from Echinocoryne pungens (Gardn.) H. Rob. and Echinocoryne stricta (Gardn.) H. Rob. The last two could not be distinguished using pollen characters. Our datashow that pollen characters alone are not enough to define the three genera.

Palinotaxonomia de espécies de Lepidaploa (Cass.) Cass. (Vernoniinae - Compositae) ocorrentes no Sudeste do Brasil

The pollinic study of 23 species of Lepidaploa that occur in southeastern Brazil was done with the objetive of contributing to the pollinic characterization of these species and also evaluating its taxonomic position. The pollen grains were acetolysed, measured, described and ilustrated under light microscopy. For further details of pollen surface and aperture, non acetolysed pollen grains were analysed by scanning electron microscopy (SEM) and, subsequently, electron-micrographed. Characteristics of pollen grains like shape, size and constitution of exine and aperture were studied. The pollen of the species analysed in this study varies from medium or large in size, isopolar, suboblate, oblate spheroidal or prolate spheroidal, subtriangular ambit, small or large polar area, 3-colporate with echinolophate surface. A key to identify the studied species was made based on pollinic data. Pollen grains from Lepidaploa have four main brochus organization pattern of the echinolophate exine. Three of these patterns can be divided into subtypes according to the apertural lacune shape.

Palinotaxonomia de Albertinia brasiliensis Spreng., Eremanthus bicolor (DC.) Baker e Vanillosmopsis erythropappa (DC.) Sch. Bip. (Compositae-Vernonieae)

Vanillosmopsis Sch. Bip. has been traditionally accepted as a synonym of Eremanthus Less., and Albertinia Spreng. was established to include Albertinia brasiliensis Spreng. This paper characterizes the pollen of Albertinia brasiliensis, Vanillosmopsis erythropappa and Eremanthus bicolor and provides information for future taxonomic studies. Pollen grains of specimens collected in different herbaria were used in this study. The two first species are found in Rio de Janeiro, but Eremanthus is not found in this state. For this reason, the type species of this genus was used for pollen analysis. Pollen grains were acetolysed, measured, described and illustrated using optical microscopy. Non-acetolysed pollen grains were used for analysis in scanning electron microscopy. The results showed that these species can be distinguished using mainly exine ornamentation and aperture features, revealing an interspecific evolutionary gradation of pollen characteristics. As regards the taxonomy of the species studied, the palynological data confirm the taxonomic position of Albertinia brasiliensis, but they do not support the subordination of Vanillosmopsis to Eremanthus.

Pollen morphology of the genus Paralychnophora (Vernonieae–Asteraceae)

Paralychnophora is an exclusively Brazilian genus that has few species and a confusing taxonomy. The current study aims to help us better understand this genus by analysing pollen grains from six Paralychnophora species. The pollen grains were acetolysed, analysed and photomicrographed under light microscopy. They were not acetolysed for the scanning electron microscopy analysis. Features such as shape, size, exine constitution and aperture were investigated. The species were separated in a pollen key, and their features were of great diagnostic value for the genus. The ornamentation pattern allowed separating P. patriciana from P. reflexoauriculata, and it grouped the other taxa. P. atkinsiae distinguished itself by the polar area index (PAI) size. P. bicolor, P. harley and P. glaziouana were easily separated from each other when other features such as size, shape, distance between the spines and aperture dimensions were analysed together.

Pollen morphology of some related genera of Vernonieae (Asteraceae) and its taxonomic significance

Pollen morphology is an important source of information to increase systematic resolution in Asteraceae, especially in Vernonieae. Aiming to investigate if palynological traits give support to Caatinganthus, Strophopappus and Xiphochaeta as separate genera from Stilpnopappus, we used cluster analysis followed by a test of group sharpness. Further, ordination analysis was applied to detect informative pollen traits associated with the revealed groups. The analyses evidenced five groups: (G1) Caatinganthusrubropappus as a single-species group; (G2) species of Stilpnopappus; (G3) Xiphochaetaaquatica as a single-species group; (G4) Strophopappusbicolor, S.glomeratus, S.villosus, S.ferrugineus, S.pohlii and S.speciosus; (G5) Strophopappusbullatus and S.regnelli. The interruption in the middle of the muri in apertural lacunae explains the single-species group Caatinganthusrubropappus. The thickness of sexine, the type of apertures (porate or colporate), and spine dimensions (length, thickness and distance from each other) are the traits explaining differences between species of Stilpnopappus and Strophopappus. Equatorial lacunae give support to Xiphochaetaaquatica as a single-species group, despite the smaller size of pollen grains of this species as compared to the others species analyzed. The differences among pollen morphology give support to Caatinganthus, Stilpnopappus, Strophopappus and Xiphochaeta as genera according to the taxonomic classification currently accepted. The used approach was efficient to reveal individual pollen traits informative to explain the sharp groups, and was an effective alternative to the use of “pollen types”.

Baccharis subgen. Molina (Asteraceae) no estado do Rio de Janeiro, Brasil

Baccharis comprises c. 340 species occurring in the Americas. The tufted indumentum, with trichomes having a single adjoining basal cell, and florets functionally unisexual are diagnostic characters of the genus. The Rio de Janeiro state flora contains 55 species of this genus. This work presents the results of taxonomic studies of Baccharis subgen. Molina (Pers.) Heering in Rio de Janeiro state. The subgenus is represented by 18 species belonging to four sections - Caulopterae (8 spp.), Molinae (4 spp.), Baccharidastrum (3 spp.), and Trinervatae (3 spp.). A key for the identification of sections and species, plus morphological descriptions, illustrations, and comments on geographic distribution and ecology are provided. Three species are new records and five are excluded from the state checklist of species.

Palinologia de espécies de Asteraceae de utilidade medicinal para a comunidade da Vila Dois Rios, Ilha Grande, Angra dos Reis, RJ, Brasil

This study is a palynologycal characterization and taxonomic description of 12 species within 12 genera, distributed in nine tribes from Asteracaeae. All studied species are used as medicines by people from Vila Dois Rios and they occur in Ilha Grande. This work aimed to characterize the pollen grains of medicinal species of Asteraceae from Vila Dois Rios and provide diagnostic keys based on macromorphological and pollen characters to help their identification, since the correct taxonomic and palynological recognition of these species is necessary for further studies on therapeutic effectiveness and safety. It must be considered that these acknowledgments have economic importance for the community, as melissopalynology practices are taking place in Vila Dois Rios. The pollen grains were acetolysed, measured decribed and illustrated under light microscope. To observe details of aperture and surface, non acetolysed pollen grains were analysed under scanning electronic microscopy. Characteristics like shape, size, sexine and aperture constitution were studied. The results show that the palynological characterization of these species is a valuable tool to differ them from each other and sustains that Asteraceae is euripolinic.

Pollen morphology of Praxelis (Asteraceae, Eupatorieae, Praxelinae) in Brazil

Studies on the pollen morphology of 11 species of Praxelis Cass. was conducted (Praxelinae, Eupatorieae-Asteraceae). Asteraceae is the second biggest family of the angiosperms the equivalent 25,000 species distributed around the world. Praxelis, genus predominantly South American, is the second biggest in number of the species of the subtribe Praxelinae. In Brazil, the species analyzed here is represented well in “cerrado” biome, less often in the other biomes. The botanic material was utilized by exsicatas deposited in Brazilian herbarium. The pollen was acetolyzed, measured, described and illustrated under light microscope. To observe details of aperture and surface, non-acetolyzed pollen grains were analyzed and photographed under scanning electron microscope, and transmission electron microscope. Characteristics like shape, size, ornamentation and aperture constitution were studied. The species were described as: small to medium, isopolar, oblate spheroidal to subprolate, 3(4)-colporate, ornamented margin, endoaperture with or without median constriction, presence of cavea, the sexine is spinulous and always greater than nexine. Hierarchical cluster analysis (HCA) was used to divide the main pollen taxa into three groups based on pollen morphology. Statistically distinctive taxa were identified using principal components analysis (PCA). Pollen analysis revealed that the main characteristics that defined the clusters were: the shape for cluster 1, the dimensions of the aperture for cluster 2 and the size of the pollen grains, the spines and the cavea to cluster 3. It is hoped that this study contributes to a better understanding of the taxonomy of the genus and provide data for a phylogeny future.

Lectotypifications and a Validation in Baccharis (Asteraceae, Astereae) Names from Brazil

Abstract The study of collections from the RB herbarium in Rio de Janeiro, Brazil, allows the lectotypification of three names in the Asteraceae: Baccharis ×hoehneana Teodoro, B. ×paulopolitana Teodoro & W. Hoehne, and B. ×wilsoniana Teodoro. Additionally, the name B. lymanii G. M. Barroso ex G. Heiden is validated by the indication of a holotype.