This name is a synonym of Penstemon lemhiensis (D.D. Keck) D.D. Keck & Cronquist.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50306616) with original publication details: Amer. Midl. Naturalist 23(3): 612 1940.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:187782-2.
This name was in version 1 of The Plant List, record tro-50306616, and has not been changed.