This name is a synonym of Praecereus euchlorus subsp. smithianus (Britton & Rose) N.P.Taylor.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Cact. 2: 37 1920.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:52204-2.
This name was in version 1 of The Plant List, record kew-2709569, and has not been changed.