Estudos da família Asteraceae no complexo de serras da Bocaina-Carrancas e Ouro Grosso, Minas Gerais, Brasil: a tribo Vernonieae e uma nova espécie de Wedelia

Abstract

The largest family of flowering plants among the eudicots, the Asteraceae, is distributed throughout almost the entire planet and in all types of habitats; however, they are in open environments, such as fields, where it is possible to find their greatest diversity. The present work had as objective the taxonomic treatment of one of the most diverse tribes within the Asteraceae family, the tribe Vernonieae, in the quartzitic mountains of Bocaina, Carrancas and Ouro Grosso, Campo das Vertentes region, south center of Minas Gerais. The area, despite being part of the Atlantic Forest domain, due to its proximity to the Cerrado domain, is directly influenced by the composition of this domain and with that, several vegetational physiognomies typical of the Cerrado can be observed, among them the campos rupestres. The region's mountains are full of grassy fields surrounding quartzite outcrops in the higher portions, and savannahs, dirty fields, seasonal and gallery forests in the lower portions. In total, in addition to the new species Wedelia multiaristata, 52 species of the tribe Vernonieae were found and described. The genera with the greatest richness were Lessingianthus with 12 species, followed by Chrysolaena, Lepidaploa and Eremanthus with five species each. The genera Centratherum, Hololepsis and Lychnophora had only one species each. Among the 52 species found, only Lepidaploa gnaphaloides is categorized as Endangered by CNCFlora. The physiognomies with the highest species richness were the rupestrian fields with 80.7%, followed by the cerrados with 55.7%, and the clean fields with 48%, other physionomis together presented 32.6%. About 40.3% of the species found are endemic to the Brazilian Cerrado domain, and only Eremanthus syncephalus and Lychnophora pinaster are endemic from campos rupestres. In the study area, the Vernonieae tribe appears with the highest species richness (52 spp.) in relation to the Eupatorieae tribe (41 spp.), different from several other areas of campo rupestre where the Eupatorieae tribe is often identified with the highest species richness. The species Lepidaploa gnaphalioides was the one that presented the highest degree of threat according to CNCFlora: Endangered (EN).