International Bureau for Plant Taxonomy and Nomenclature
Taxon vol:59 issue:4 pages:1065-1076
Mentheae are the largest tribe in the family Lamiaceae and economically important, including herbs like mint, sage and thyme. The evolutionary history of this tribe was reconstructed based on ITS and trnL-trnF spacer sequence data of 71 species, representing. 47 out of 65 genera. The resulting phylogeny was used to analyse the distribution of selected morphological characteristics such as sexine ornamentation of pollen, nutlet shape with existence of abscission scar and its form, and trichome types. Two monophyletic groups are recognized, which largely correspond to the current subtribal circumscription. Subtribe Salviinae is monophyletic, including the genus Melissa which was a genus of uncertain affinity in Mentheae. Subtribe Menthinae is not monophyletic since Cleonia, Horminum, Hyssopus, Lycopus and Prunella are more closely related with subtribe Nepetinae. Although we could not detect any morphological synapomorphies for each clade, morphological variation seems to be correlated with the molecular phylogeny. A circular abscission scar without distinct lateral areole occurred mainly in Salviinae, while the majority of the species of Mentheae and Nepetinae had a clear areole at the abscission scar. In addition, a reticulate sexine ornamentation is rather common in the Menthinae clade.