Genus Sideritis is ranged in Western Palaearctic by 193 species classified into two subgenus and
seven sections. Its species diversity mainly concentrated in Mediterranean basin. The subgenera
and sections in the genus were established by traditional taxonomy and their monophyly has not
been tested. Using 19 representative species from seven sections belonging to subgenera Sideritis
and Marrubiastrum we aimed to test monophyly of the subgenera. We defined and coded 26
morphological characters and applied a parsimony analysis choosing a Stachys sp. as outgroup.
The majority rule consensus tree of the 9 equally parsimonious trees suggested the following
relationships: ((((((S. montana + (S. lanata + S. romana) + (S. barbellata + (S. discolor + S.
cretica + (S. macrostachys + (S. nutans + S. gomerae))))) + S. stachydioides) + S. scardica) + S.
condensata + (S. siplylea + (S. cilicica + (S. hyssopifolia + (S. glacialis + (S. osteoxylla + S.
bourgeana)))))) + S. syriaca) + Stachys sp.. In the light of these data, the following main
conclusions were raised: (i) Neither subgenera nor sections in the genus Sideritis are
monophyletic, (ii) most of characters that were used for descriptions of subgenera and sections
are homoplastic and (iii) as species in the Empedoclia section occupy the basal branches of the
each main clades possibly this section represent ancestor