The legume genus Mimosa comprises approx. 500 species, most of which are native to the New World, with Brazil being the main centre of radiation, but ancient transoceanic dispersal resulted in the Indian subcontinent hosting up to six endemic species. Gehlot et al. examine the nodulation ability and rhizobial symbionts of two of these, M. hamata and M. himalayana, both from north-west India, and compare them with those of M. pudica, an invasive species. In contrast to all Brazilian Mimosa species so far examined, which are nodulated by rhizobia in the Betaproteobacterial genus Burkholderia, the symbionts of the two Indian species are identified as belonging to the Alphaproteobacterial genus Ensifer (syn. Sinorhizobium). The invasive M. pudica is predominantly nodulated by Betaproteobacteria in the genera Cupriavidus and Burkholderia, and it does not share symbionts with either native species.