Investigation of the evolutionary trend of morphological characters of Stachys (Lamiaceae) in Iran based on nrITS sequences data

The evolutionary trend of the morphological characters of the genus Stachys in Iran, on the basis of nrITS se-quence data, was investigated. A total of 28 nrITS sequences, representing 26 species of Stachys as well as Betonica of-ficinalis and Melittis mellisophyllum, were obtained from GenBank. Patterns of character evolution were assessed for 10 vegetative and reproductive characters with emphasis on taxonomic treatments of Stachys performed earlier to infer its history and interpret processes of change. The most important characters included habitat, growth form, leaf morp-hology, inflorescence, calyx and corolla as well as trichome morphology. Phylogenetic tree, based on the nrITS dataset, were constructed by Bayesian analysis. Parsimony mapping was performed in Mesquite v. 1.12. The present analysis revealed that the state of symmetrical calyx, the presence of basal leaves as well as the presence of glandular trichomes were not in agreement with the results of molecular data, which indicated the artificial nature of these characters in pr-evious classification. The presence of simple trichomes as well as the growth forms were consistent with phylogeny ba-sed on nrITS sequences. Evolutionary trend of morphological characters demonstrated that the sect. Eriostomum and sect. Fragilicaulis were the most primitive and the most advanced sections in Iran, respectively