Three new taxa are described from the Arizona Strip in northwestern Arizona: Camissonia dominguez-escalantorum N.D. Atwood, L.C. Higgins & S.L. Welsh, sp. nov.; Physaria arizonica (S. Watson) O'Kane & Al-Shehbaz var. andrusensis N.D. Atwood, S.L. Welsh & L.C. Higgins, var. nov.; and Tetradymia canescens DC. var. thorneae N.D. Atwood, S.L. Welsh & L.C. Higgins, var. nov. Two new taxa are described from New Mexico: Lepidium montanum Nutt. ex Torr. & A. Gray var. todiltoensis N.D. Atwood & S.L. Welsh, var. nov. and Hymenoxys argentea (A. Gray) K.F. Parker var. thoreauensis N.D. Atwood, S.L. Welsh & A. Clifford, var. nov. Two new species are described from Utah: Camissonia bolanderi N.D. Atwood & S.L. Welsh, sp. nov. and Erigeron katiae S.L. Welsh and N.D. Atwood, sp. nov. Each is compared to related species based on differences in morphology.