1. The karyotypes of three species of Gymnaster, five species of Kalimeris and three species of Heteropappus were studied by an oxyquinoline aceto-orcein technique.
2. The karyotypes of these genera are characterized by the presence of symmetrical chromosomes with median-submedian centromeres.
3. Chromosomes with secondary constrictions (L^2E-chromosomes) were found with the exception of G. koraiensis.
4. Judging from their karyotypes, polyploid species of the genera Kalimeris and Heteropappus are considered to be allopolyploids.
5. Differences in karyotypes are sufficient to separate the section Homolepis from the section Crassifolium of the genus Gymnaster and the section Asteromoea from the section Cordifolium of the genus Kalimeris. However, the cytological similarity of the karyotypes of Gymnaster, Kalimeris and Heteropappus to the genus Aster is of such a degree that the former three genera could be regarded as sections of Aster.