This name is a synonym of Euphorbia engelmannii Boiss..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 37953) with original publication details: Cas. Nár. Mus., Odd. Prír. 140: 169 1972.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:340622-1.
This name was in version 1 of The Plant List, record kew-37953, and has not been changed.