Search

Floristic relationships between the Irano-Turanian and Mediterranean regions have been known from old. However, only a few biogeographical analyses based on molecular data have evaluated the history of steppe plants within the Mediterranean basin. Our study aims to contribute to a better understanding of the migratory and diversification processes by reconstructing the biogeography of Rhaponticoides (Cardueae), distributed in the Mediterranean and Irano-Turanian regions. We generated nuclear and plastid sequences that were analyzed by Bayesian inference. We used the resulting phylogeny for dating the diversification of the genus and examining the dispersal pathways. Two clades were recovered, an Irano-Turanian clade and a Mediterranean clade. The origin of the genus was placed in the Anatolian plateau in the Middle Miocene. The genus experienced several diversifications and expansions correlated to the Messinian salinity crisis and the environmental changes in the Pliocene and the Quaternary. Rhaponticoides migrated following two routes reflecting the two souls of the genus: Irano-Turanian taxa colonized the steppes of Eurasia whilst Mediterranean species migrated via eastern and central Mediterranean and North Africa, leaving a trail of species; both pathways ended in the Iberian Peninsula. Our study also confirms that more work is needed to unravel phylogenetic relationships in Rhaponticoides.

Two new species of Centaurea subg. Cyanus (Asteraceae) from Anatolia are described and illustrated. Centaurea akcadaghensis Uysal & Şirin occurs on open Quercus forest of Levent Canyon (Akçadağ-Malatya) and differs from C. matthiolifolia Boiss. mainly in stem, leaves, central flowers and achenes measures. Centaurea ermenekensis Şirin & Uysal is restricted to steppes of Göktepe (Ermenek-Karaman) and can be distinguished from C. reuteriana Boiss. by the stem, number of capitula, involucre and median appendages measures.

Two new species of Centaurea subg. Cyanus (Asteraceae) from Anatolia are described and illustrated. Centaurea akcadaghensis Uysal & Şirin occurs on open Quercus forest of Levent Canyon (Akçadağ-Malatya) and differs from C. matthiolifolia Boiss. mainly in stem, leaves, central flowers and achenes measures. Centaurea ermenekensis Şirin & Uysal is restricted to steppes of Göktepe (Ermenek-Karaman) and can be distinguished from C. reuteriana Boiss. by the stem, number of capitula, involucre and median appendages measures.