CENTAUREA SECT. CYANUS: NUCLEAR PHYLOGENY, BIOGEOGRAPHY, AND LIFE-FORM EVOLUTION

Section Cyanus of Centaurea is a group that is very well defined morphologically and, thus, is a good representative of many radiations of eastern groups of the genus in the Mediterranean region. To confirm the existence of the two natural groups, subsect. Cyanus (annual species) and subsect. Perennes (perennial taxa), typically defined within this section, and to confirm their radiation patterns, a molecular phylogenetic analysis was carried out using the highly variable nuclear-ribosomal spacers ITS (internal transcribed spacer) and 3'ETS (external transcribed spacer). Our results confirm the eastern origin of the group, which probably arose from a Caucasian and North Iranian stock. Both subsections are monophyletic, and annuals (subsect. Cyanus) arose from perennials in Anatolia. The radiations of the two subsections follow very different patterns. Inconsistencies between present classifications and molecular results strongly suggest that the present delineation of some species (Centaurea triumfetti being the best example) is incorrect, and a deep taxonomic revision is necessary.