Heterocyphelium leucampyx(Arthoniales, Ascomycota): another orphaned mazaediate lichen finds its way home

Abstract

AbstractHeterocypheliumis a mazaediate genus containing a single species,H. leucampyx. The species was originally described from Cuba within the genusTrachylia(Arthoniales,Arthoniaceae) and later placed in various genera of the collective orderCalicialess. lat. For the past three decades,Heterocypheliumwas considered an orphaned genus (incertae sedis) within the Ascomycota, since morphology alone could not resolve its systematic position. In this study, we added molecular data with the aim of resolving this uncertainty. Bayesian and maximum likelihood analyses of newly generated sequence data from the mitochondrial ribosomal RNA small subunit (mtSSU) and the RNA polymerase II second largest subunit gene (RPB2) provide clear evidence thatHeterocyphelium leucampyxis nested within the orderArthoniales, in the familyLecanographaceae, sister to the genusAlyxoria.Heterocypheliumis a further example of parallel evolution of passive spore dispersal, prototunicate asci and the occurrence of a mazaedium in the Ascomycota, and another calicioid genus whose systematic placement could be eventually clarified by means of molecular data.Heterocypheliumis the fourth mazaediate genus inArthoniales, in addition toSporostigma,TylophorellaandTylophoron.