Drought meets acid: three new genera in a dothidealean clade of extremotolerant fungi

Fungal strains isolated from rocks and lichens collected in the Antarctic ice-free area of the Victoria Land, one of the coldest and driest habitats on earth, were found in two phylogenetically isolated positions within the subclass Dothideomycetidae. They are here reported as new genera and species, Recurvomyces mirabilis gen. nov., sp. nov. and Elasticomyces elasticus gen. nov., sp. nov. The nearest neighbours within the clades were other rock-inhabiting fungi from dry environments, either cold or hot. Plant-associated Mycosphaerella-like species, known as invaders of leathery leaves in semi-arid climates, are also phylogenetically related with the new taxa. The clusters are also related to the halophilic species Hortaea werneckii, as well as to acidophilic fungi. One of the latter, able to grow at pH 0, is Scytalidium acidophilum, which is ascribed here to the newly validated genus Acidomyces. The ecological implications of this finding are discussed. Taxonomic novelties: Recurvomyces Selbmann & de Hoog, gen. nov.; Recurvomyces mirabilis Selbmann & de Hoog, sp. nov.; Elasticomyces Zucconi & Selbmann, gen. nov.; Elasticomyces elasticus Zucconi & Selbmann, sp. nov.; Acidomyces Selbmann, de Hoog & De Leo, gen. nov.; Acidomyces acidophilus (Sigler & J.W. Carmich.) Selbmann, de Hoog & De Leo, comb. nov.