Molecular data favours a monogeneric Peltulaceae (Lichinomycetes)

The family Peltulaceae is currently composed of the three genera Peltula, Phyllopeltula and Neoheppia. The last two genera, both with two species, are distinguished from Peltula only by a small number of morphological characters. The morphology of the genus Peltula varies from peltate-umbilicate thalli to squamulose-semifruticose or squamulose-compound types, as well as subfoliose-compound and crustose types. All types have an upper epinecral layer and possess medullary cavities of various sizes; a lower cortex is normally present but is usually not developed in the subfoliose and crustose types. The genera Neoheppia and Phyllopeltula differ from the common Peltula morphology by crustose-areolate and subfoliose-compound thalli, respectively. Both Neoheppia and Phyllopeltula are additionally characterized by the absence of medullary cavities and lower cortices. To investigate the phylogenetic validity of Phyllopeltula and Neoheppia, we sequenced six loci from representatives of these two genera together with 37 species from Peltula. Despite the relatively high amount of conflict among loci, the results clearly indicate that both Phyllopeltula and Neoheppia are not monophyletic, and are nested within the genus Peltula. Consequently, we subsumed species of these two genera within the genus Peltula.