This name is a synonym of Penstemon breviculus (D.D. Keck) G.T. Nisbet & R.C. Jacks..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 29204299) with original publication details: Bull. Torrey Bot. Club 65(4): 241–242 1938.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:187563-2.
This name was in version 1 of The Plant List, record tro-29204299, and has not been changed.