Fig. 4.

Range map of host-specific clades of Orobanche sect. Gymnocaulis. Coloured circles represent individuals sampled in the phylogeny (Figs 1–3). Coloured lines show the approximate range of each clade. Further study is needed to determine the range of each of the three host-specific lineages of O. uniflora subsp. occidentalis, which in this figure are treated as one unit. Range maps should be considered tentative, particularly in northern Canada and west-central USA, pending a thorough taxonomic and phytogeographical study.