The genus Veronica includes about 200 species occurring throughout the Northern Hemisphere. Several genera have been split from Veronica in the last hundred years, such as shrubby Hebe from New Zealand or Pseudolysimachion with long corolla tubes. An analysis of ITS-sequence data for 70 taxa including 37 species of Veronica and several segregate genera neither supports the monophyly of Veronica in the widest sense nor the monophyly of Veronica as used today. According to our analysis, the tribe Veroniceae is monophyletic including Veronica, the "Hebe-complex", Paederota, Pseudolysimachion, Synthyris (and Besseya), Veronicastrum, Wulfenia, and Lagotis. The genus Veronica is split into at least four clades with the Australasian species of the "Hebe-complex" and the genera Synthyris, Paederota, and Pseudolysimachion being nested within Veronica. The relationship between these clades, however, is not well supported. The intraspecific classification of Veronica so far has been mostly based on inflorescence morphology. The most important character for that matter is the presence or absence of a terminal inflorescence. Character state changes, however, seem to be more common than formerly assumed. Other characters will, therefore, be more important taxonomically in the future. Biochemical characters may be important in that sense, but they are also interesting for pharmaceutical reasons with several species of the tribe used in folk medicine. The analysis of ITS-sequence data underlines especially the value of chromosome numbers in the taxonomy of Veronica. A comparison of the ITS phylogeny with chromosome numbers reveals well supported groups showing a constant chromosome number with only few exceptions. The inferred phylogeny of Veronica and related genera does not only have serious implications for the taxonomy of the group but also for its biogeography and spread of the tribe in the tertiary.

Key words: ITS, Lamiales, molecular systematics, Scrophulariaceae, Veronica