This name is a synonym of Euphorbia pubentissima Michx..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 333691) with original publication details: J. Elisha Mitchell Sci. Soc. 80: 173 1964.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:101447-2.
This name was in version 1 of The Plant List, record kew-333691, and has not been changed.