Polystichum setiferum at the northeastern limit of its distribution range

During field studies in 2019 in the Beskid Śląski mountain range in southern Poland, one individual morphologically resembling Polystichum setiferum was found. Nuclear DNA content analysis confirmed the species identity. The new stand of P. setiferum corresponds to historical literature reports and herbarium specimens from the Czech Republic and Poland, and extends the northeastern limit of the distribution of this species. As the historical stands in both countries have not been confirmed, the newly discovered stand is at present strongly isolated, as the nearest extant locations of P. setiferum in Austria, southern Hungary, and western Romania are nearly 500 km away. Therefore, this unique stand deserves special attention and protection.