Nomenclatural Changes in Mammillaria and Pelecyphora: Repopulating Oehmea and Neobesseya

Soon-to-be-published findings from a molecular phylogenomic and biogeographic study of the Mammilloid Clade indicate that there is a strongly supported clade congruent with the circumscription of the genus Oehmea. Another strongly supported clade was recovered that is outside of the recent circumscription of the genus Pelecyphora, containing the type species for the genus Neobesseya. We transfer two taxa to Oehmea, and we restore Neobesseya and carry out new combinations in that genus. These changes reflect findings from several earlier phylogenies and morphological groups, as well as our own results, and emphasize the value of phylogenomics in better understanding the evolutionary relationships in recently diverging and species-rich genera in Cactaceae.