Anatomical, cytological and phytochemical studies on Phlomis L. and Eremostachys Bunge (Labiatae)

Observations made on the anatomy of Phlomis and Eremostachys confirm previous views that the two genera are closely related, but characters such as trichomes and petiole structure can be used to distinguish species and groups of species. Within Phlomis, two distinct groups can be recognized using chromosome data. Phlomis section Phlomis has fewer (2 n = 20) and larger chromosomes and Phlomis section Phlomoides has more (2 n = 22) and smaller chromosomes. Eremostachys has chromosomes corresponding to those of Phlomis section Phlomoides.
Flavones are similar in both Phlomis and Eremostachys; the shrubby species belonging to Phlomis section Phlomis also have flavonols.