The genus Artemisia, the largest in the tribe Anthemideae and one of the larger in the family Asteraceae, comprises around 500 taxa at specific and subspecific levels, largely distributed in the temperate regions of Northern Hemisphere. It includes several species that dominate the landscape in arid and semi-arid areas, as well as some useful taxa. The currently most accepted infrageneric classification consists of five big groups (Artemisia, Absinthium, Dracunculus, Seriphidium and Tridentatae), the limits and the systematics of which have been controversial. In order to achieve a natural classification of the genus and a definite idea about its phylogeny, we undertook the study of its genome at three levels: cytogenetics, genome size and internal transcribed spacers (ITS) of nuclear ribosomal DNA sequencing. The major findings of our research are presented in this contribution. Artemisia chromosomes are rather small and symmetrical. Dysploidy (two basic numbers, x=9 and x=8) and polyploidy (ploidy levels ranging from 2x to 12x) are the two main mechanisms of chromosomal evolution in the genus. Banding techniques and fluorescent in situ hybridization (FISH) allowed us to establish some differences between taxa or groups of species. Nuclear DNA amount shows a seven-fold variation in the genus. Some variations have systematic implications whereas some others are linked to ecological selection pressures. ITS sequencing provided a consensus tree that allows us to confirm the delimitation of the genus, including Seriphidium, which has been treated as an independent genus by several authors. Three more big groups (Absinthium, Dracunculus and Tridentatate) are also well defined, whereas Artemisia does not appear as a homogeneous group. The combination of all these data and those from studies that we are presently carrying out in Artemisia and related genera will probably throw light on the systematics and the phylogeny of the entire subtribe Artemisiinae.

Key words: Anthemideae, Artemisia, Asteraceae, cytogenetics, molecular phylogeny, systematics