With such a diversity of chromosome numbers and broad morphological diversity within Melampodium, these data have impacted classification within the genus. Chromosome numbers have been seen as significant at the sectional level going back to the first comprehensive revision. New molecular phylogenetic studies have greatly improved the understanding of evolutionary relationships, especially among three species of the former Sect. Alcina, all n = 11. This section now has only one species left (M. perfoliatum), the other two being segregated into two other monotypic taxonomic sections (M. nutans into Sect. Nutantia; M. glabrum into Sect. Glabrata). AFLP population genetic markers have contributed to confirming the taxonomy of the white-rayed complex, with the exception that M. cinereum var. hirtellum harbors two distinct genetic and geographic populational systems. An updated classification of the genus is presented.