Figure 4.

Structure analyses. Evanno et al.'s (2005) ΔK values for each putative number of populations (K) for (A) Arctotheca populifolia and (B) Petrorhagia nanteuilii. Structure Q plots generated using the maximum value of ΔK indicate A. populifolia (C) and P. nanteuilii (D) samples represent two genetic groups each, demarcated by labeled bars (i.e., A₁). Samples from the introduced range are denoted by asterisks. Each individual is represented by a vertical line showing degree of admixture. Sample name abbreviations are defined in Figure 1.