Cytological Studies on Subfam. Carduoideae of Japanese Compositae (VI). Karyotype Analysis in the Genus Artemisia

1. The karyotypes of eight species in the genus Artemisia were studied by the smear method with the pretreatment of 8-oxyquinoline.2. The chromosome numbers of A. apiacae and A. montana are here reported for the first time, and for A. montana, a number different from the previous determinations has been recorded.3. Based on the karyotypical stand point, A. princeps and A. montana seem to be amphidiploid forms of a basic number of 17 and 26, respectively.4. The common karyotypical characteristics of the genus Artemisia are represented by the existence of a pair of short chromosomes with subterminal constrictions and of the larger chromosomes which have the secondary and terminalized primary constrictions. And the karyotype is generally symmetrical.5. A. montana may be derived from some species with the same chromosome number of 2n =18 as in A. stelleriana by a loss of a pair of trabants of median-sized chromosomes which have secondary constrictions and show variations in some other minute karyotype details.6. The basic chromosome number of most species in the genus Artemisia appears to be 9. However, in A. Feddei, a diploid number of 16 was observed. Some species with higher chromosome numbers (2n =34, 52) are presumably of amphidiploid origin.