⚠ Version 1 of The Plant List has been superseded.
This name is in version 1.1 of The Plant List, record tro-50126831, with some changes.
This name is a synonym of Penstemon whitedii subsp. dayanus (Howell) D.D. Keck.
The record derives from Tropicos which reports it as a synonym (record 50126831) with original publication details: Fl. N.W. Amer. 5: 511-512 511 1901.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:187333-2.