A phylogenetic analysis and biogeographical distribution of Teucrium Sect. Teucrium (Lamiaceae) and taxonomic notes for a new species from southwest Turkey

Teucrium L. is a well-known and cosmopolitan genus of the Lamiaceae family. In Turkey, the genus is represented by 36 species (48 taxa). Teucrium Sect. nucrium that this study focuses on comprises around 30 species worldwide and is mainly distributed in countries of the Mediterranean Basin. With 11 species (14 taxa), it is the second-largest section of the genus Teucrium in Turkey. In this study, morphological and molecular findings were evaluated and the phylogeny and biogeographical distribution of Sect. nucrium were analyzed. Also, five endemic taxa belonging to Sect. Teucrium and which play an informative role in the subsectional classification of the section were analyzed for the first time. A new species of the genus nucrium from southwest Turkey was described as T. semrae Aksoy, Dirmenci & Ozcan and analyzed using different approaches. The infrageneric position of T. semrae in sect. Teucrium and the phylogenetic structure of the section were determined according to morphological and micromorphological features and molecular nrITS and cpDNA data. The phylogenetic position of the new species was argued by comparing the closest members. Comparative figures and illustrations, distribution maps and an updated identification key for the Sect. Teucrium in Turkey are presented, and a new detailed classification is proposed in this study.