This name is a synonym of Argemone ochroleuca subsp. stenopetala (Rose) Ownbey.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Contr. U. S. Natl. Herb. 8: 27 1903.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:18869-2.
This name was in version 1 of The Plant List, record kew-2650579, and has not been changed.