<i>Cortinarius spilomeoalpinus</i> (<i>Basidiomycota</i>, <i>Agaricales</i>) a new alpine species of sect.<i> Spilomei</i> from South-Tyrolean <i>Dryas octopetala</i> habitats

During our long-term studies on <i>Cortinarius</i> species in alpine habitats, we discovered several collections of a <i>Cortinarius</i> species resembling <i>C. spilomeus</i>. We carried out comparative morphological studies and a phylogenetic analysis based on rDNA ITS sequences. We included also type material of <i>Cortinarius spilomeus forma dryadicola</i>. We confirmed that <i>Cortinarius spilomeoalpinus</i> is a distinct species which is typical for alpine <i>Dryas octopetala</i> habitats. <i>Cortinarius spilomeus forma dryadicola</i> is not part of <i>C. spilomeus</i> sensu stricto. It is conspecific with the later described <i>C. ferrusinus</i>, another taxon of sect. <i>Spilomei</i>, and we treat it as <i>forma</i> of it. Detailed descriptions are given for the alpine taxa, and a differential diagnosis and dichotomous identification key are provided. <b>Citation:</b> Peintner U, Huymann L, Ferrari RJ (2025). <i>Cortinarius spilomeoalpinus</i> (<i>Basidiomycota, Agaricales</i>) a new alpine species of sect. <i>Spilomei</i> from the South-Tyrolean <i>Dryas octopetala</i> habitats<i>. Fungal Systematics and Evolution</i> <b>15</b>: 265-274. doi: 10.3114/fuse.2025.15.12.