XVI International Botanical Congess

The monotypic genus Cnicus L. is one of numerous small genera within Centaureinae subtribe, which are disputed from the taxonomic point of view. According to some investigators, the majority of the genera from this group are closer morphologically to Centaurea L. We investigated achenial envelope microstructure of Cnicus benedictus L. to clarify the relationships between these genera. The results were compared with the data published for Centaurea (Mouradian, 1999). The comparative analysis revealed similarity only in spermoderm structure. However, pericarp of C.benedictus dominates and has 19-20 rather big, closely settled ribs with well developed mechanical tissue. This is not characteristic for Centaurea species and these features, in our opinion, can be a forcible argument proving the independence of the genus Cnicus.