The Erythranthe clade in Mimulus contains species are adapted to different pollinators and one species that reproduces mainly through self-pollination. Section Erythranthe contains six species, five of which are hummingbird pollinated and one is bee pollinated. The estimated phylogeny of this group using data from ITS, ETS, and trnL/F shows no resolution for relationships among species, but does support the monophyly of the Erythranthe clade if the highly selfing, annual, desert-adapted M. parishii is included. Sister to Erythranthe is a clade that includes M. bicolor, M. filicaulis, and M. rubellus. 488 AFLP bands were scored for all of the species in Erythranthe and its sister clade, including multiple populations for most species. Results of analyses of AFLP fragment data indicate: 1) Erythranthe is monophyletic, 2) a high amount of genetic differentiation exists between M. lewisii populations in the Sierra Nevada and those in the Pacific Northwest and Rocky Mountains. To further investigate the relationships among species, DNA from each species (including both races of M. lewisii) was combined and an additional 400 AFLP fragments were collected which resulted in a phylogeny for the group. A well-resolved clade containing species in the Sierra Nevada, the Pacific Northwest and the Rockies is sister to another well-resolved clade containing species in Mexico, Arizona, and Utah. The highly selfing M. parishii is resolved as sister to all other species or as sister to a clade containing M. lewisii and M. cardinalis . The common ancestor of the Erythranthe clade is inferred to be annual, insect-pollinated and from the Sierra Nevada. Hummingbird pollination is inferred to be derived within the clade and may have arisen twice independently. Allopatric speciation is suggested to be the major mode of speciation in the clade.

Key words: AFLP, Erythranthe, hummingbird pollination, Mimulus, self-pollination, speciation