Patterns of diversification in Chionohebe and Parahebe (Scrophulariaceae) inferred from ITS sequences

Phylogenetic relationships of Chionohebe and Parahebe were inferred from an alysis of ITS sequences. The results suggest that the genus Parahebe is pol yphyletic as currently circumscribed, and the genus Chionohebe may be parap hyletic by exclusion of some of the alpine Parahebe. Parahebe lithophila em erges with the Australian endemics Derwentia and Hebe formosa. The alpine s pecies of Parahebe emerge with Chionohebe, Hebe cheesemanii, and H. cupress oides. Parahebe Groups A and B of Ashwin emerge with Hebe and Heliohebe. Th e origin of the New Zealand taxa is equivocal. Chionohebe densifolia, C. ci liolata, and Parahebe vandewateri have New Zealand ancestry and have subseq uently dispersed to Australia and New Guinea. The mountains of New Zealand are an important centre of diversification, and it appears that evolution i n the group has been rapid. Autogamy has independently evolved in at least two lineages and may be an adaptation to alpine environments.