This name is a synonym of Euphorbia arizonica Engelm..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 38287) with original publication details: Contr. U. S. Natl. Herb. 25: 345 1925.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:55463-2.
This name was in version 1 of The Plant List, record kew-38287, and has not been changed.