This name is a synonym of Oenothera laciniata var. grandiflora (S. Watson) B.L. Rob..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50086034) with original publication details: Proc. Amer. Acad. Arts 8: 581 1873.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:281550-2.
This name was in version 1 of The Plant List, record tro-50086034, and has not been changed.