Penstemon washoensis Penstemon lassenianus Penstemon depressus Penstemon confertus var. attenuatus Penstemon confertus var. caeruleo-purpureus Penstemon confertus var. violaceus Penstemon confertus var. caeruleopurpureus Penstemon confertus var. rigidus
World Flora Online, http://www.worldfloraonline.org/, accessed June 20, 2024