This name is a synonym of Oenothera cheiranthifolia var. viridescens (Hook.) Hoover.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50082464) with original publication details: Man. Fl. Pl. Calif. 684 1925.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:173425-2.
This name was in version 1 of The Plant List, record tro-50082464.