This name is a synonym of Penstemon pandus (A. Nelson & J.F. Macbr.) A. Nelson & J.F. Macbr..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50108006) with original publication details: Bot. Gaz. 55(5): 382 1913.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:187660-2.
This name was in version 1 of The Plant List, record tro-50108006, and has not been changed.