We conducted the present study on seven important medicinal species of Achillea (in a total of 28 populations) in their natural habitats. The results indicated that the populations had a base number (x= 9) and the diploid, tetraploid, and hexaploidy levels were observed. In addition to the inter-species diversity, there was the intra-species genetic diversity as A. millefolium (4x, 6x), A. vermicularis (2x, 4x), A. tenuifolia (2x, 4x), A. Aleppica (2x), A. talagonica (2x), A. biebersteinii, and A. wilhelmsii (4x). Furthermore, studies also indicated that 11 out of 28 populations had 1A symmetry, 15 populations had 2B symmetry, a population had 2A, and another population had 2B. Cluster analysis of cytogenetic variables could differentiate only the species of A. aleppica, A. talagonica and A. wilhelmsii but others could not separate differences between species appropriately, probably due to the superiority of intra-species diversity of populations to inter-species diversity. Furthermore, we found %TF and DRL are useful parameters for differentiating intrachromosomal variation of species
