Seven Centaurea L. (Asteraceae) taxa endemic to Turkey were examined in terms of anatomical and molecular aspects to contribute to their taxonomic positions. Numerical analysis of the 13 anatomical traits showed that average row number of collenchyma and the arrangements of the vascular bundles in the stem, leaf type, and abaxial surface of leaf epidermal tissue were important to determine the investigated taxa. | Turkish Journal of Botany Research Article Turk J Bot (2013) 37: 419-427 © TÜBİTAK doi: A contribution to taxonomy of Centaurea including Psephellus (Asteraceae) based on anatomical and molecular data Özhan AYDİN, Kamil ÇOŞKUNÇELEBİ*, Mutlu GÜLTEPE, Murat Erdem GÜZEL Department of Biology, Faculty of Science, Karadeniz Technical University, 61080 Trabzon, Turkey Received: Accepted: Published Online: Printed: Abstract: Seven Centaurea L. (Asteraceae) taxa endemic to Turkey were examined in terms of anatomical and molecular aspects to contribute to their taxonomic positions. Numerical analysis of the 13 anatomical traits showed that average row number of collenchyma and the arrangements of the vascular bundles in the stem, leaf type, and abaxial surface of leaf epidermal tissue were important to determine the investigated taxa. It was also found that the 7 investigated taxa were grouped into 2 distinct clusters based on anatomical traits and combined nrDNAITS/cpDNA data. Key words: Anatomy, Centaurea, cpDNA, endemic, ITS, Turkey 1. Introduction The genus Centaurea L. . has about 800 species distributed mainly in the Mediterranean area and south-western Asia (Wagenitz & Hellwig, 1996). Centaurea has one of the highest rates of endemism in Turkey, with 112 endemics among 181 total species (Güner et al., 2000). The high endemism ratio shows that Turkey is one of the gene centres of this genus (Celik et al., 2008). Recently, the genus Centaurea has been divided into several distinct genera, namely Centaurea, Rhaponticoides Vaill., Psephellus Cass., and Cyanus Mill. (Wagenitz & Hellwig, 2000; Greuter, 2003a, 2003b; Susanna & Garcia-Jacas, 2006). Centaurea was divided into 34 sections by Wagenitz (1975) in the Flora of Turkey. In this classification, C. sessilis Willd. and C. armena Boiss. are treated under the sect. Rhizocalthium Tzvelev. C. kilaea Boiss.,
