This name is a synonym of Euphorbia lata Engelm..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 38061) with original publication details: Fl. S.E. U.S. 710 1903.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:55321-2.
This name was in version 1 of The Plant List, record kew-38061, and has not been changed.