Chromosome number and morphology in nine taxa belonging to 10 populations of Tanacetum L. (Asteraceae) were investigated using karyological techniques. The chromosome number found in eight species was 2n = 18 (T. balsamita, T. budjnurdense, T. sonbolii, T. archibaldii, T. persicum, T. parthenium and T. canescens) while T. polycephalum subsp. duderanum and T. polycephalum subsp. azerbaidjanicum had 2n = 36. Six records are new while four records confirmed the previous data. At mitotic metaphase, all chromosomes had median point (M), median region (m), submedian (sm) or subterminal (st) centromeres. The karyotypes are classified in types 2A or 2B, showing the presence of a primitive symmetrical karyotype in the genus Tanacetum. An updated checklist of karyological data of the genus is also presented.
