Remarks on the karyogeography of Myosotis alpestris in Europe

Results are presented of the karyological study of selected populations of Myosotis alpestris F. W. Schmidt. Particular attention has been paid to a locality of phytogeographical importance, the Maly Kociol (the Malá Sněžná Jáma) Cirque, the Krkonoše Mts., Poland . In spite of the fact that the occurrence of the species is satisfactorily documented from this isolated locality (herb. PR, PRC), Myosotis alpestris has not been re-found there during the excursions in 1991-1993. On the basis of the analysis of pollen size in herbarium specimens from the Krkonoše, tetraploid chromosome number is estimated for them. In addition, chromosome numbers were analyzed in 13 populations of Myosotis alpestris F. W. Schmidt from the Jura (2n=48), the Alps (2n=24,48,72), the Carpathians (2 n=48) and the Balkans (2n=24, 48). The chromosome number 2n=48 is published for the first time for the Slovakia and the Romania. In one population of M. sylvatica Hoffm. from the Krkonoše Mts. chromosome number 2n=l8 was found, as well. The correlation between pollen size and ploidy level has also been studied and statistically significant differences were found between cytotypes belonging to different ploidy levels.