The genus Lychnophora Mart. comprises about 68 endemic species in "campos rupestres" in the States of Minas Gerais, Bahia and Goias. Ecological conditions of this environment possibly favored an intense speciation, and could be one factor for this endemism. The highest diversity is found in Minas Gerais, a state also considered as the major center of dispersal of this genus. To contribute to the biosystematic study of the genus, we carried out a chromosomic study in 18 species of Lychnophora, belonging to 3 sections, collected at the mountain ranges of Cip6 and of the regions of Carrancas and Diamantina, all in the State of Minas Gerais. Three chromosome numbers, n=17, 18 and 19 were found in different species and a polyploid population with n=34 was detected in L. staavioides. These different chromosome numbers are distributed among species of the 3 sections and can not be used as distinctive characters at an infrageneric level. On the other hand, they are very important to differentiate some species whose limits sometimes are questioned.

ResumoEste trabalho consiste no levantamento florístico de Asteraceae nos Campos Rupestres das Serras da Bocaina e de Carrancas que estão localizadas no Planalto Alto Rio Grande, no sul de Minas Gerais, bem como uma análise de similaridade florística com outras áreas serranas do Planalto Brasileiro. O levantamento florístico foi realizado em 11 áreas localizadas nas Serras da Bocaina e de Carrancas. A similaridade florística foi realizada entre outras 17 áreas de Campos de Minas Gerais, São Paulo, Rio de Janeiro e Bahia. Neste levantamento florístico, a família apresentou 117 espécies, distribuídas em 43 gêneros pertencentes a 14 tribos. Os gêneros que têm maior riqueza de espécies são Baccharis (14), Lessingianthus (10), Mikania (8) e Chromolaena (8). As Serras da Bocaina e de Carrancas apresentaram maior similaridade florística com a Serra da Canastra, Serra de São José e Toca dos Urubus, enquanto a menor similaridade apresentada foi com a Serra dos Órgãos. Não houve correlação significativa em relação à similaridade florística e a distância geográfica entre as áreas analisadas. As relações na composição florística entre os grupos formados provavelmente estão relacionadas com aspectos geomorfológicos, edáficos, climáticos, além da influência vegetacional dos domínios fitogeográficos onde estes campos estão inseridos. Palavras-chave: Cerrado, afloramento rochoso, espécies endêmicas, similaridade florística AbstractThis work reports on a floristic survey of Asteraceae in rocky outcrop grasslands on the Bocaina and Carrancas mountain range, located in the Upper Rio Grande highlands, southern Minas Gerais State, as well as on an analysis of floristic similarity between mountainous areas of Brazilian Plateau. The floristic survey was carried out in 11 areas on the Bocaina and Carrancas mountain range. The floristic similarity was carried out between 17 other grasslands of Minas Gerais, São Paulo, Rio de Janeiro and Bahia. In this floristic survey, the family showed 117 species, 43 genera and 14 tribes. The richest genera were Baccharis (14), Lessingianthus (10), Mikania (8) and Chromolaena (8). The mountain range of Bocaina and Carrancas showed highest floristic similarity with the mountain range of Canastra, mountain range of São José and Toca dos Urubus, while the lowest similarity were with the mountain range of Órgãos. There was no significant correlation in relation to floristic similarity and geographical distance between the areas analyzed. The relationships in floristic composition between the groups formed are probably related to geomorphological, edaphic, climatic, vegetation beyond the influence of phytogeographic domains where these grasslands are located.

BackgroundThe search for new inhibitors of snake venom toxins is essential to complement or even replace traditional antivenom therapy, especially in relation to compounds that neutralize the local effects of envenomations. Besides their possible use as alternative to traditional antivenom therapy, some plant species possess bioactive secondary metabolites including essential oils, which can be extracted from weeds that are considered substantial problems for agriculture, such as Hedychium coronarium.MethodsThe essential oils of leaves and rhizomes from H. coronarium were extracted by hydrodistillation, and their potential inhibitory effects on the coagulant and fibrinogenolytic activities induced by the venoms of Lachesis muta, Bothrops atrox and Bothrops moojeni were analyzed. Citrated human plasma was used to evaluate the clotting time whereas changes in fibrinogen molecules were visualized by electrophoresis in polyacrylamide gel. The experimental design used for testing coagulation inhibition was randomized in a 3 × 2 factorial arrangement (concentration × essential oils), with three replications. The essential oils were compared since they were extracted from different organs of the same botanical species, H. coronarium.ResultsThe results suggest that the oils interact with venom proteases and plasma constituents, since all oils evaluated, when previously incubated with venoms, were able to inhibit the clotting effect, with less inhibition when oils and plasma were preincubated prior to the addition of venoms.ConclusionsThus, after extensive characterization of their pharmacological and toxicological effects, the essential oils can be used as an alternative to complement serum therapy, especially considering that these plant metabolites generally do not require specific formulations and may be used topically immediately after extraction.

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-The chromosomal numbers of three species of Bidens were determined based on an analysis of somatic metaphases. The species studied were Bidens pilosa L., Bidens subalternans DC and Bidens alba (L.) DC, all of which belong to the Bidens pilosa species complex. The three species have a similar morphology: Bidens pilosa and B. subalternans are widely distributed in agricultural areas, in disturbed habitats and along roadsides, whereas B. alba occurs only along the seacoast. Bidens pilosa has 2n=72 and B. subalternans and B. alba has 2n=48. These numbers agreed with the basic chromosomal number of n=12 reported for the tribe Heliantheae and show that the number of metaphase chromosomes can be used to distinguish Bidens pilosa from the other two species of the B. pilosa complex in southeastern Brazil.

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The genera Lychnophoriopsis and Paralychnophora are endemic to Brazilian 'campo rupestre' in the States of Minas Gerais and Bahia. To analyse the status of the cytotaxonomy of these genera, we carried out chromosome counts on several species. Two chromosome numbers were obtained for four species of Paralychnophora : 2 n = 36 and 2 n = 38. For three species of Lychnophoriopsis , only 2 n = 36 was observed. The chromosome size (1.0-2.58 µ m) and morphology (mainly metacentric, with some submetacentric) were analysed in four species of Paralychnophora and showed relative constancy .

Paepalanthus mollis var. mollis is placed in Paepalanthus subg. Xeractis (Eriocaulaceae) and, until now, it was considered endemic to the campos rupestres of the Espinhaço Range in Minas Gerais, Brazil. We report here the new occurrences of this species from the municipalities of Carrancas and Minduri, at the southern part of the mountain complex of Bocaina and Carrancas. These specimens confirm the occurrence of this species and the subgenus outside the Espinhaço Range. These occurrences are also the southernmost sites of geographic distribution of the group.