Asteraceae from Barra da Estiva: the use of floristic inventories suggests two bioregions in the Chapada Diamantina - Brazil

Abstract Asteraceae is one of the most diverse families in the world, especially in mountainous regions such as Chapada Diamantina, Bahia, Brazil. The objectives of this work were to carry out a floristic survey of Asteraceae in the municipality of Barra da Estiva, discuss the distribution of species found, and analyze the similarity between the Asteraceae diversity in Barra da Estiva and other previously evaluated areas. Herbaria were reviewed, and three field trips were carried out. Barra da Estiva houses 98 species of Asteraceae grouped into 46 genera and 13 tribes. The tribes Vernonieae (34 spp.) and Eupatorieae (24 spp.) were the most diverse, especially the genera Baccharis (7 spp.) and Lepidaploa (7 spp.). A matrix of species presence/absence for different phytophysiognomies was elaborated according to the rendered species list and previous Asteraceae surveys in Chapada Diamantina. Although previous research considered the Chapada Diamantina a single phytogeographic unit, our results suggest its possible subdivision into two bioregions: ‘Piemonte da Diamantina’, including areas of the extreme northeast, and Central-South Chapada, encompassing areas from the central-south region.