This name is a synonym of Euphorbia porteriana (Small) Oudejans.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 331417) with original publication details: Ann. Missouri Bot. Gard. 53: 99 1966.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:55394-2.
This name was in version 1 of The Plant List, record kew-331417, and has not been changed.