The genus Vernonia is one of the most complex in the family Asteraceae. The large variety of biological forms found in Vernonia and the possibility that this genus may actually consist of many genera have resulted in considerable discussion about the validity of this genus in its current form. In this work, we analyzed the chromosome numbers of species of Vernonia (section Lepidaploa sensu Baker) that occur in Brazil in order to assess whether this genus should be retained in its current form (sensu Baker) or split into several smaller genera (sensu Robinson), such as Lepidaploa, Lessingianthus, Chrysolaena and Vernonanthura. Analysis of the chromosome numbers and chromosomal indexes of Vernonia species compiled from the literature showed that there was no clear association between karyotypic characters and both taxonomic treatments for the groups. Supported by phylogenetic studies available in literature, we suggests that the chromosome numbers multiples of 10 (in Chrysolaena and some species of Lepidaploa and Lessingianthus) are caused by decreasing aneuploidy from x = 17, basal for American Vernonieae.