Taxonomic delimitations within the Penstemon scariosus Pennell (Plantaginaceae) complex. - STEVENS, MIKEL R.; JOHNSON, ROBERT L.; STETTLER, JASON M.; MESERVEY, LINDSEY M.; ROBBINS, MATTHEW D.; ANDERSON, CHRIS D.; PORTER, SYDNEY J.; RICKS, NATHAN J.; HARRISON, SARAH (Monographs of the Western North American Naturalist, 2022)