Taxonomic evaluation of the tetraploid populations of Cardamine amara (Brassicaceae) from the Eastern Alps and adjacent areas

Tetraploid populations of C. amara occupying the area of the Eastern Alps a nd neighbouring areas are described as a new subspecies, C. amara subsp. au striaca Marhold. The distribution area of these populations largely coincid es with the area heavily affected by Pleistocene glaciation and it is sugge sted that the polyploidization event or events occurred during interglacial or early postglacial periods. Morphometric analysis of diploid and tetrapl oid populations of C. amara revealed that the new subspecies is morphologic ally close to diploid C. amara subsp. amara, but it can be separated from t his taxon by the combination of several morphological characters from among of which the size of pollen grains is the most important.