This name is a synonym of Penstemon gracilis var. wisconsinensis (Pennell) Fassett.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50108796) with original publication details: Scroph. E. N. Amer. 234, map 55 1935.
This name was in version 1 of The Plant List, record tro-50108796.