Morphological and chemical evidence of Teucrium x rohlenae K.Malý (Lamiaceae), a new hybrid in Croatia

Several natural hybrids between Teucrium montanum L. and T. polium L. have been described in certain parts of the area where this two species are in sympatry. A new population with intermediate individuals that share morphological characteristics of both T. montanum and T. polium is found in Croatia (Bisko near Trilj), and most likely represent a hybridogenous taxon. The aim of this study is to compare morpho-anatomical and phytochemical characteristics of two parental species and their putative hybrid, as well as to determine the most important distinguishing characters between these three groups. In order to describe the variability and significance of morpho-anatomical and phytochemical differentiation of analysed groups several multivariate statistical analysis were conducted (PCA, CDA, DFA, UPGMA-clustering). All analyses confirm the separation of two species, T. polium and T. montanum, and reveal intermediate position of their putative hybrid. In this way, data of morphological and anatomical analysis together with data of the composition of the essential oils support the assumption of the hybridogenous origin of intermediate individuals. Based on descriptions and original indication of parental species of previously described hybrids T. x castrense Verg., T. x bogoutdinovae Melinkov and T. x rohlenae K.Malý, we found that intermediate specimens collected in Croatia perfectly match with T. x rohlenae, a hybridogenous taxon discovered by Rohlena in the vicinity of Kotor in Montenegro, and thus prove a presence of a new natural hybrid in the flora of Croatia.