Does a citizen science project describe the biogeography of exotic Aureoboletus projectellus in Poland? An ethnomycological survey

<i>Aureoboletus projectellus</i> is an American <i>Boletaceae</i> fungus that appeared on the shores of the Baltic Sea at the beginning of the 21^st century. The mushroom was soon gathered by local communities, and fungi enthusiasts travelled from all over Poland to gather this new food item. The aim of our study was to investigate the spread of the invasive <i>Aureoboletus projectellus</i> and its use in mycophylic Poland through an interview-based ethnomycological survey (carried out in the field and online). We gathered 274 questionnaires, and recorded many new localities of the species inland, all over the country, far from the original sites of introduction along the Baltic Sea. We have not found any clear correlation between the origin of the collectors coming to hunt it by the Baltic Sea and its localities inland. On the other hand, the interviews conducted as part of the project revealed 56 new localities of <i>A. projectellus</i> in Poland. This demonstrates that citizen science initiatives can yield valuable biogeographical and ethnobiological data, even for complex and poorly understood groups of organisms such as fungi. It seems that the species is already well-established in Poland, and used in dishes similarly to other <i>Boletaceae</i> species. Its local names often contain the word 'American' or 'heather' due to its origin and preferred habitat.