A new species of bulbil-forming lichenicolous fungi represents an isolated clade in the Cantharellales

Abstract

Lichenicolous species are widely distributed in the Basidiomycota, and many are known to produce sclerotia or bulbils with few additional structures to permit taxonomic placement. The Cantharellales include many of these species and we here describe a new genus and species discovered in Austria that grows over Physcia aipolia and P. stellaris and forms minute dark reddish brown bulbils reminiscent of Ceratobasidium bulbillifaciens but much smaller in size. We obtained sequences of ITS and nuLSU rDNA representing the herbarium specimen of the species, and initial searches in GenBank indicated it was a member of the Cantharellales, with closest relatives in the genus Minimedusa. We inferred its phylogenetic placement in the order using an existing dataset that included all known lichenicolous species, augmented by sequences obtained by BLAST searches in GenBank. Our results indicate that the unknown is not closely related to any described lichenicolous species or to any other described bulbilliferous species in the order. Based on these results, we are now establishing a new genus and species, Bergerella atrofusca, in the Cantharellales family Hydnaceae.