Two ploidy levels of genetically delimited groups of the Calypogeia fissa complex (Jungermanniopsida, Calypogeiaceae)

Calypogeia fissa is a suboceanic-mediterrean and amphiatlantic species, which comprises two subspecies: C. fissa subsp. fissa occurring in Europe and C. fissa subsp. neogea Schust. known from North America. Recently, within the European part of distribution, three groups (P_S, P_B and G) were distinguished with the aid of genetic and molecular markers. The flow cytometry results revealed that two of the detected groups of the European C. fissa, which are frequent in Poland (P_S and P_B), differ in ploidy level: the P_S group is haploid, whereas the P_B group is diploid. Isozyme pattern at two loci may suggest an allopolyploid origin of the diploid P_B group.