Elizabeth K. Seifert, James D. Bever, and John L. Maron. 2009. Evidence for the evolution of reduced mycorrhizal dependence during plant invasion. Ecology 90:10551062.
Appendix A. Locations of North American and European Hypericum perforatum populations.
FIG. A1. Locations of the 14 European H. perforatum populations.
FIG. A2. Locations of the 15 North American H. perforatum populations.