The genus Selaginella P. BEAUV. (Selaginellaceae, Lycopodiopsida) in Poland: The occurrence of three species as a result of the historical material verification

Two species of the Selaginella genus were noted in Poland up to date, i.e. S. selaginoides and S. helvetica. The first species occurs in the Western Carpathians and the Western Sudetes, however, its Sudeten sites were less numerous than previously reported. The second species was one of the rarest elements in Polish flora. Two populations were reported in Silesia (SW Poland), but after 1945 the species was not confirmed in the nature and thus currently it is regarded in Poland as extinct. Its occurrence and locations were given in the literature based on the historical sources, yet without revision of herbarium materials. Our research on Selaginella vouchers, collected from the sites in Silesia and primarily identified as S. helvetica, showed that only one population represented S. helvetica, whereas the second one was identified by us as an alien American species, S. apoda. This is the first record of S. apoda occurrence in Poland out of cultivation, and the second in Europe. Accordingly, corrected maps of S. selaginoides, S. helvetica and S. apoda distribution in Poland together with the identification key to the species are presented.