The secotioid genus Galeropsis (Agaricomycetes, Basidiomycota): a real taxonomic unit or ecological phenomenon?

Despite the recent mycologists’ interest in relationships between gasteroid taxa and agaricoid Basidiomycetes lineages and an intensive debate on the evolution of enigmatic secotioid fungi, systematic studies of the genus Galeropsis have received little attention. Here, the taxonomy of this genus is revised based on morphological and nuclear ribosomal DNA (ITS and LSU) data. The genus is shown to be polyphyletic, with at least five phylogenetic lineages corresponding to known genera of Agaricomycetes (Panaeolus, Agrocybe, Parasola, Conocybe, and Leratiomyces). The type species of Galeropsis, G. desertorum, is combined to Panaeolus, and other six new combinations are proposed. In total, eight type collections are studied. The lectotype for Psammomyces plantaginiformis is designated here. Gastrocybe iberica is placed as synonym of Panaeolus desertorum, and the names Galeropsis andina and Galeropsis bispora are synonymized under Panaeolus plantaginiformis. The detailed morphological descriptions and illustrations of microscopic structures for all studied species are given. The phylogenetic inference and our current understanding of the phylogenetic structure and ecology of Galeropsis are discussed.