This name is a synonym of Penstemon seorsus (A. Nelson) D.D. Keck.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 29204274) with original publication details: Bot. Gaz. 54(2): 147–148 1912.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:187458-2.
This name was in version 1 of The Plant List, record tro-29204274, and has not been changed.