Polemoniaceae, the phlox family, includes about 400 species of herbs, shrubs, small trees, and vines. Some members of this family are common desert, montane, or woodland wildflowers that form spectacular displays during their brief blooming periods. Scarlet gilia (Ipomopsis aggregata), with showy, bright red flowers, is one of the most obvious and frequently collected summer wildflowers in its range. Few species in this family are economically important, although some are commonly grown in home gardens, and others are found in herbal dietary supplements. In the plant sciences, the phlox family is an important model for investigating pollination biology and evolutionary patterns (e.g. Galen, 2000; Mayfield et al., 2001; Campbell et al., 2003; Lendvai and Levin, 2003). Various species are adapted for pollination by bats, hummingbirds, bees, both short- and long-tongued flies, beetles, butterflies, or moths (Grant and Grant, 1965). Important insights into plant speciation, especially among annual plants, have been gained from studies of species in this family (Grant, 1981). Many interesting patterns of variation that can further enlighten our understanding of diversification modes and mechanisms remain to be addressed.