A re-evaluation of North American Tephroseris and Sinosenecio (Asteraceae : Senecioneae) based on molecular and micromorphological data

The recent transfer of the Queen Charlotte island endemic, Senecio newcombe i Greene (Senecioneae: Asteraceae), to the Asiatic genus Sinosenecio extend s the biogeographic range of Sinosenecio to North America and introduces a large amphi-Beringian gap in the distribution of the genus. However, the cl osely related genus Tephroseris includes a number of North American species with distributions in the vicinity of S. newcombei. We provide molecular s equence data from the ITS region of nuclear ribosomal DNA and micromorpholo gical data from anther endothecial cells that indicate S. newcombei is clos ely related to North American Tephroseris species. However, the overall rel ationship between Sinosenecio and Tephroseris remains unresolved, so that t ransfer of S. newcombei to Tephroseris is not proposed.