This name is a synonym of Euphorbia cowellii (Millsp. ex Britton) Oudejans.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 37928) with original publication details: Bull. Torrey Bot. Club 43: 457 1916.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:274426-2.
This name was in version 1 of The Plant List, record kew-37928, and has not been changed.