Myriochapsa and Nitidochapsa, two new genera in Graphidaceae (Ascomycota: Ostropales) for chroodiscoid species in the Ocellularia dade

Two new genera, Myriochapsa M. Caceres, Lucking & Lumbsch and Nitidochapsa Parnmen, Lucking & Lumbsch, are introduced for the species Chapsa psoromica and C. leprieurii, which are not genuine Chapsa species but related to Myriotrema and Ocellularia, respectively. The following two new combinations are proposed: Myriochapsa psoromica (M. Caceres, Santos de Jesus & Santos Vieira) M. Caceres, Lucking & Lumbsch comb. nov., and Nitidochapsa leprieurii (Mont.) Parnmen, Lucking & Lumbsch comb. nov. Myriochapsa psoromica is morphologically and chemically similar to Myriotrema species but differs in the wider apothecial pore with fissured-lobulated margin; it is known only from the western Amazon (Brazil: Rondonia). Nitidochapsa leprieurii is characterized by a brown, nitidous thallus and Chapsa-like apothecia with wide, pruinose disc and lobulate to recurved, felty, white margin; it has brown ascospores and lacks secondary compounds. The species is pantropical. The interpretation of phenotype characters in a molecular phylogenetic framework is discussed.