Taxonomic Revision of (Peltigeraceae, Ascomycota), Reveals a New Genus and Three New Species.

The lichen genus exhibits significant morphological and chemical variations between species. Recent molecular studies have demonstrated that is polyphyletic, underscoring the need for a comprehensive taxonomic revision. Phylogenetic analyses employing Bayesian methods and Maximum Likelihood approaches based on three molecular loci (nrITS, nrLSU, mtSSU) revealed that species of segregate into two distinct clades. The first clade includes species characterized by bright orange lower surfaces that contain secondary metabolites, notably solorinic acid. The type species, , is retained in the genus . The second clade encompasses species with white or brownish lower surfaces; most species lack secondary metabolites and are now classified as a new genus, . As a result of this taxonomic revision, two species: and remain in the genus . Five species with white or brownish lower surfaces were transferred to the new genus , which consists of three newly described species and five new combinations. Four species previously described as , , , and have morphology consistent with , but are currently retained in due to the absence of supporting DNA sequence data. A key to and is provided. The spores of exhibit wall ornamentation featuring rounded papillae, which are distinct from those of . Molecular data and morphological characters also indicate that both and engage in symbiotic associations with photobionts cyanobacteria and chlorophytes or .