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The purpose of this study is to provide a new focus to contribute, from the perspective of genomic evolution, towards a better understanding of the Valerianaceae evolutionary history. Chromosome numbers were determined by Feulgen staining in 24 populations of 18 species (first count for Valerianella multidentata, 2n=2x=14–16), and DNA contents were assessed by flow cytometry in 74 populations of 35 species (first assessments in all taxa but Centranthus ruber). A molecular phylogeny based on the trnL-trnF and including 41 new sequences was established, with the first DNA sequence for Centranthus nevadensis, Valeriana rotundifolia, V. saxatilis, Valerianella multidentata, and V. turgida. This work is the first large genome size study devoted to the Valerianaceae, showing a range of DNA amounts from 2C=0.39 pg (Valerianella turgida) to 2C=8.32 pg (Valeriana officinalis). At the family level, changes in basic chromosome number and genome size coincide with or precede major shifts in the evolutionary history of the group, such as those concerning stamen number and floral symmetry.

Chromosome counts in 12 Artemisia species from Russia are presented in this paper. Chromosome numbers of A. czekanowskiana, A. globosa, A. ledebouriana, A. lithophila, A. macilenta, A. pycnorhiza and A. sosnovskyi are reported for the first time. The chromosome counts carried out in A. czekanowskiana (2n=10x=90) and A. macrantha (2n=12x=108) indicate cases of aneusomaty. The presence of a dicentric chromosome and acentric fragments or a B-chromosome is reported for one species. Besides these, genome size in 21 populations of 18 species of Artemisia belonging to the subgenus Dracunculus, mainly from Russia and Mongolia, has been assessed by flow cytometry. The nuclear DNA content ranges from 2C=4.21 to 2C=24.58 pg, and the nuclear DNA content per basic chromosome set (1Cx) from 2.06 to 3.00 pg. The constancy of genome size has been evaluated concluding that there exists a nuclear DNA loss (at the 1Cx-value level) within ascending ploidy levels. Possible correlations between genome size, morphological traits and the phylogenetic position of species have been tested.