⚠ Version 1 of The Plant List has been superseded.
This name is in version 1.1 of The Plant List, record tro-50079705, with some changes.
This name is a synonym of Penstemon alpinus subsp. magnus (Pennell) Penland.
The record derives from Tropicos which reports it as a synonym (record 50079705) with original publication details: Contr. U.S. Natl. Herb. 20(9): 346 346 1920.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:187471-2.