AbstractDetailed analyses of micro- and macromorphological features of 247 specimens representing the Polypodium vulgare complex, combined with DNA content measurements, revealed the presence of tetraploid P. vulgare s.str., hexaploid P. interjectum and the pentaploid hybrid P. × mantoniae in the Polish Sudetes. For species identification, sporangium structure (number of indurated and basal annulus cells) was found to be the most stable and thus the most valuable and taxonomically significant character. The size of spores and stomata was related to taxon ploidy level, and helped to differentiate the examined taxa. Polypodium interjectum was identified from only one locality in the Pogórze Kaczawskie foothills; P. × mantoniae was more widely distributed, suggesting that it is rather common in the Polish Sudetes. Both newly reported taxa occur mainly on basic or neutral rock in sheltered, shaded or semi-shaded habitats.