This name is a synonym of Euphorbia vaginulata Griseb..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 38281) with original publication details: Publ. Field Columb. Mus., Bot. Ser. 2: 302 1909.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:55457-2.
This name was in version 1 of The Plant List, record kew-38281, and has not been changed.