In this paper, I describe five new species of Selaginella from Brazil (S. nanuzae, S. neospringiana, S. pellucidopunctata, S. stomatoloma, and S. trygonoides), compare them to morphologically similar species, and provide a preliminary conservation status assessment for each. The new species are illustrated with scanning electron photomicrographs of stem sections, leaves, and spores, when available. Also discussed in this paper are ten species, mainly from Brazil and with new distribution records, and the forthcoming resurrection of three species also occurring in Brazil. Three further non-native and presumed naturalized species are recognized in Brazil, and publication of one additional taxon is planned. Eighty-six Selaginella species are now known from Brazil and, of these, 80 are native (including 26 / 32.5%, endemic), and six are introduced. Brazil and Mexico have the second highest number of native Selaginella species in the Neotropics after Venezuela, which is estimated to have about 100. Of the newly documented species, S. cabrerensis is now known to occur in French Guiana, Brazil, and Bolivia, in addition to Colombia, and S. arroyoana and S. chiquitana are synonymized under it. Likewise, S. potaroensis is also recorded from Costa Rica and Brazil, and S. seemannii from Panama and Brazil. Finally, leaf marginal stomata are reported on the newly described species and their functionality is discussed under S. stomatoloma.
