New species from Argentinean Yungas, Cercopemyces messii and Clitocybe cedrelae (Agaricomycetes, Agaricales)

The Argentine Northwest has a system of tropical and subtropical montane cloud forests on the Andes Mountains, where there is a significant diversity of Agaricales fungi yet to be discovered. Two new species from the Cedrela forest, inside the Baritú National Park, Argentina, are described in this work as Cercopemyces messii and Clitocybe cedrelae. Phylogenetic analysis was performed using the nuclear internal transcribed spacer (nrITS) region and the large subunit (nrLSU) of the nuclear ribosomal RNA. Complete taxonomic descriptions, field photographs, drawings, photographs captured with the scanning electron microscope (SEM) of the basidiospores, and comparisons of the similar and closely related species are provided. Both taxa have ornamented basidiospores that are hyaline, inamyloid, and clamp connections in all tissues. They were also found within the same area, and both presented a good number of specimens. These striking species should be considered in danger since their natural habitats are also at risk.