The Canary Islands consist of seven islands forming a volcanic archipelago off the northwest coast of Africa. The location and relative isolation of these islands has made them a rich source of endemic plants. The unique flora of the Canary Islands includes approximately 600 endemic species with at least 23 endemic genera that represent 40% of the native plant species of these islands. The genus Bystropogon (Lamiaceae) is endemic to the Macaronesian region and is represented by 11 species in the Canary Islands and one species in Madeira. These taxa are distinguished by both morphological and ecological differentiation in addition to geographic distribution. The incredible morphological flexibility of island plants that allows them to adapt to new and diverse environments has made the study of the systematic relationships of island endemics a challenging endeavor. The recent use of molecular tools has allowed for new insights in understanding the systematic and biogeographic relationships of island taxa. An ITS phylogeny of all the species of Bystropogon has resolved the relationships of these taxa in Macaronesia and offers insight into the plasticity of morphological adaptation in this group.

Key words: Bystropogon, Canary Islands, ITS, molecular phylogeny