Photos of each species and respective subgenus included in this study.

• Main Authors: Jason M. Stettler (5488874), Mikel R. Stevens (11841089), Lindsey M. Meservey (11841092), W. Wesley Crump (11841095), Jed D. Grow (11841098), Sydney J. Porter (11841101), L. Stephen Love (11841104), Peter J. Maughan (8887367), Eric N. Jellen (8887364)
• Format: Still Image
• Language: unknown
• Published: 2021
• Subjects: Genetics; Evolutionary Biology; Ecology; Plant Biology; Environmental Sciences not elsewhere classified; Biological Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; recent geologic origin; provides greater accuracy; old world taxa; monophyletic clade sister; higher nodal support; div >< p; analyzing phylogenetic relationships; plastome based phylogeny; complete plastome sequences; resolving problematic clades; improving phylogenetic resolution; concatenated chloroplast sequences; six subgenera occupying; plastome based phylogenies; concatenated sequences; phylogenies based; major clades; improves resolution; temperate grasslands; scrophulariaceae </; rps2 </; rpoc2 </; rbcl </; rapid rate; psba </; psaa </; pleistocene transition; plastid genomes; plantaginaceae </; perennial forbs; penstemon </; ndhf </; matk </; lamiales using; lamiales order; arid deserts; arctic tundra; alpine meadows; Arctic; Tundra
• Online Access: https://doi.org/10.1371/journal.pone.0261143.g001

Clockwise from the upper left: Penstemon fruticosus ( Dasanthera ), P . rostriflorus ( Saccanthera ), P . personatus ( Cryptostemon ), P . palmeri ( Penstemon ), P . cyaneus ( Habroanthus ), and P . dissectus ( Dissecti ). Photo credits: Mikel R. Stevens and Jason M. Stettler.