This name is a synonym of Penstemon leiophyllus var. francisci-pennellii (Crosswh.) N.H. Holmgren.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 29204321) with original publication details: Leafl. W. Bot. 10(10): 170–171 1965.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:282301-2.
This name was in version 1 of The Plant List, record tro-29204321.