Figure S7. County Range Maps.

Figure S7. United States county maps colored to reflect the occurrence patterns of each of the three species: a) V. cassinoides b) V. nitidum c) V. nudum. Species occurrences were determined by visual inspection of herbarium specimens and georeferenced to county. d) all three species are shown together with V. cassinoides in blue, V. nitidum in red, and V. nudum in green. Counties with more than one species are black.