The North American genus Townsendia comprises approximately 25-30 taxa that occur predominantly at mid to high elevations in the Rocky Mountains. Most species have narrow distributions: some are restricted to specific edaphic conditions, and species of Townsendia are assigned conservation status in both Canada and the United States. The genus includes annual, biennial and perennial taxa. In addition, diploid sexual and polyploid asexual populations occur in a number of species, and the genus has been considered a single agamic complex. We have sequenced the nuclear ribosomal spacers ETS and ITS for representatives of most taxa. Phylogenetic trees obtained from separate and combined analyses are all essentially congruent and reveal strong support for the monophyly of the genus, and the presence of a number of well-supported groupings. The deepest divergence within Townsendia separates the only annual species, T. annua, from the remainder of the genus. This findings contradicts the hypothesis proposed in Beamanís 1957 monograph of the genus. In addition, our analysis reveals that apomixis and polyploidy are scattered among groups that include species known only as diploid sexuals. One well-supported clade includes a number of taxa known to have apomixis, but three additional groupings include both sexual and apomictic species. Thus, the genus provides an ideal study system in which to examine the evolution and spread of apomixis.

Key words: apomixis, Asteraceae, ETS, ITS, phylogeny, polyploidy, Townsendia