Many species and infraspecific taxa in Mimosa are narrow endemics. Following the same pattern, two new Brazilian species of the genus, M. perplicata and M. serpensetosa are described, both from the Southern Espinhaço Range (one from Serra do Cabral, the other from Serra de Capanema and Serra do Cipó), in Minas Gerais state, a region known as a key area for Mimosa diversity. The description of more species sharing affinities with M. setosa var. paludosa indicates that the latter may be acting as a species pump.