We sequenced over 200 recent specimens of Lecanora s.lat. from Brazil, delimiting 28 species in our material. Many seem to represent undescribed species, some of which being morphologically and chemically similar to each other or to already described species. Here, we present a phylogenetic analysis based on ITS, including our specimens and GenBank data. We describe nine new species. The purpose of the paper is to illustrate the diversity of the genus in Brazil, not to focus on segregate genera. However, we found that all Vainionora species cluster together and these will be treated separately. Other Lecanora species with dark hypothecium clustered in several different clades. Species with the morphology of Lecanora caesiorubella, in which currently several subspecies with different chemistry and distribution are recognized, fall apart in different, distantly related clades, so they cannot be regarded as subspecies but should be recognized at species level. A key is given for the Lecanora species from Brazil.
Keywords: Lecanoraceae; South America; chemistry; cryptic species; delimitation.