A checklist of pteridophytes from Santa Isabel do Rio Negro is presented as a contribution to the knowledge of the flora of Brazilian amazon. In the region predominate the flood-forests and two different environments can be recognized, the "igapós", and the "sub-bosques". Forty eight species belonging to 15 families were found: Aspleniaceae (3 spp.), Blechnaceae (1 sp.), Davalliaceae (1 sp.), Dennstaedtiaceae (3 spp.), Dryopteridaceae (3 spp.), Hymenophyllaceae (5 spp.), Lomariopsidaceae (5 spp.), Lycopodiaceae (1 sp.), Metaxyaceae (1 sp.), Polypodiaceae (9 spp.), Pteridaceae (6 spp.), Schizaeaceae (4 spp.), Selaginellaceae (3 spp.), Tectariaceae (1 sp.), and Vittariaceae (2 spp.). The "sub-bosque" has the highest diversity and some epiphytic species can be found on both environments ("igapó" and "sub-bosque").
Amazon forest; Amazonas State; pteridophytes; ferns; floristic
