Phylogeny of the tribe Phlomideae (Lamioideae: Lamiaceae) with special focus on Eremostachys and Phlomoides: New insights from nuclear and chloroplast sequences

The tribe Phlomideae (Lamiaceae: Lamioideae) is divided into the three genera Phlomis, Phlomoides (incl. Pseuderemostachys, Lamiophlomis and Notochaete), and Eremostachys (incl. Paraeremostachys), contains about 278 species and has a distribution range extending from Europe to Mongolia, China, and India. Here, we present a phylogenetic analysis based on nuclear ribosomal (ITS) and cpDNA (partial trnK, rpl32-trnL, and trnT-A) sequence data of 56 accessions representing all genera and major subgeneric taxa of Phlomideae. Taxon sampling covered the genera Phlomoides and Eremostachys more intensively than previous phylogenetic investigations of the tribe. Parsimony and Bayesian analyses of each marker, as well as the combined plastid datasets, produced nearly congruent trees. Monophyly of Phlomis s.str. is confirmed here, although only few representatives of this genus were included. In all obtained trees a core group of Phlomoides and Eremostachys is strongly supported. In accordance with morphological evidence, molecular data confirm the inclusion of Eremostachys, Notochaete, and Paraeremostachys in Phlomoides. In conclusion, the number of recognized genera in Phlomideae is reduced to two: Phlomis and Phlomoides. The necessary new combinations are proposed.