The reassessment of Taraxacum pieninicum reveals polyploidy, agamospermy and a substantial range extension

A remarkable West Carpathian endemic member of Taraxacum sect. Erythrocarpa (Compositae, Crepidinae), Taraxacum pieninicum Pawłowski, is reassessed from the viewpoint of its reproduction, ploidy level and taxonomy. Numerous previous experimental papers present T. pieninicum as a sexual diploid. On the basis of new, taxonomically verified material from the Pieniny Mts, using flow cytometry, FCSS and chromosome counting, T. pieninicum is shown to be a tetraploid (2n = 4x = 32) diplosporous agamospermous taxon. It proved to be conspecific with populations from western Slovakia, originally described as T. erythrocarpum Kirschner et Štěpánek. Thus, Taraxacum pieninicum is not endemic to the Pieniny Mts, but occupies a wider geographical range in the northernmost and westernmost Carpathians. It is a morphologically and taxonomically distinct member of the section Erythrocarpa, a section almost confined to the Mediterranean area in Europe. It is hypothesized that the progenitors of T. pieninicum should be sought in the northern and central Balkans and its migration or diversification probably followed the South and East Carpathian route.