This name is a synonym of Euphorbia johnstonii Mayfield.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 38046) with original publication details: Phytologia 75: 179 1993.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:973728-1.
This name was in version 1 of The Plant List, record kew-38046, and has not been changed.