Continued Progress in Mimosa (Leguminosae): Tackling the Systematics of a Big Genus in the Brazilian Flora

Big plant genera pose significant challenges for systematics. Here we present an overview of the legume genus Mimosa , one of the most diverse angiosperm genera in the Brazilian flora. Collaborative working has been key to the remarkable progress in Mimosa research in Brazil. Work carried out in the past 15 years resulted in major advances, including: the description of 42 new species and 29 new records; advances in taxonomic knowledge and revisions of major groups present in Brazil; improvement in the identification of specimens in herbaria; important contributions in phylogenetics, including evolutionary and biogeographical analyses; morphological and anatomical studies focused on different plant structures; and production of a national checklist and taxonomic treatment available online and continuously updated, as part of the Flora e Funga do Brasil initiative. The 397 Brazilian species of Mimosa (525 taxa) occupy a wide range of habitats, and are distributed across all of the country’s phytogeographic domains. Species richness/endemism are highest in the Cerrado (237/161 spp.) and Atlantic Forest (119/57), particularly in high-altitude areas. Two thirds of all Mimosa species occur in Brazil, representing most of the phylogenetic diversity of this pantropical genus. Given that many Brazilian Mimosa have restricted distributions, the genus is of high conservation concern, with 56 species currently listed as threatened. Collaborative working has been essential to recent advances in Mimosa systematics, and remains the most effective approach to address persistent knowledge gaps in this mega-diverse genus.