As classified in WFO snapshot
June 2024
Warning: older classification
subspecies
Penstemon triphyllus subsp. diphyllus
(Rydb.) D.D.Keck
This subspecies name was first published in Univ. Calif. Publ. Bot. 16: 422 (1932)
This subspecies name has been reclassified since this snapshot. Its current preferred usage is a synonym .