Polystichum setiferum rediscovered for the flora of the Czech Republic

Polystichum setiferum was rediscovered for the flora of the Czech Republic. Eight historical specimens were identified in the herbaria BRNM, BRNU, OLM, PRC, and ZMT. Credible historical records from the years 1881-1926 originate from Moravia: the Moravskoslezské Beskydy Mts. (Mt. Kněhyně and Mt. Smrk), Moravian Karst (Olomučany) and Jeseníky Mts. (Rýmařov, Mt. Praděd, Velká kotlina). An uncertain record was detected in Bohemia (Děčín, Růžovský vrch). The microcharacters (exospore length, stoma length) of these plants exhibit the same pattern as specimens of P. setiferum from Bulgaria, Romania and Serbia and they contrast with the morphologically similar P. aculeatum. The history or recognition of the species in the Czech flora is discussed and an identification key to P. aculeatum and P. setiferum is presented. The isolated occurrence of Polystichum setiferum in the Czech Republic represents the northernmost localities within its entire distributional range.