Abstract Ferns are diverse and abundant in the Lower Liassic flora of the Mecsek Mountains in south Hungary. The morphogenus Cladophlebis Brongniart, 1849, and the genus Todites Seward, 1900, show a high diversity. In the examined material, most of the characteristics used in taxonomy vary, showing transitional forms that cast doubt on the separation of species established on the grounds of either a low number of specimens, a low number of features or uncharacteristic differences.