This name is a synonym of Oenothera oakesiana var. nobska (Sturtev.) R.R. Gates.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50129500) with original publication details: Zeitschr. Abst. Vererb. 59: 367 1931.
This name was in version 1 of The Plant List, record tro-50129500, and has not been changed.