This name is a synonym of Penstemon fruticosus var. scouleri (Lindl.) Cronquist.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50338158) with original publication details: Edwards's Bot. Reg. 15: pl. 1277 1829.
This name was in version 1 of The Plant List, record tro-50338158.