Conservation genetics and breeding system of Penstemon debilis (Plantaginaceae), a rare beardtongue endemic to oil shale talus in western Colorado, USA
Andrea D. WOLFE, Amy MCMULLEN-SIBUL, V. J. TEPEDINO, Laura KUBATKO, Timothy NECAMP, Susan FASSNACHT
J Syst Evol . 2014, (5): 598 -611 .  DOI: 10.1111/jse.12100