This name is a synonym of Rhododendron × hemigymnum (Tagg & Forrest) D.F. Chamb..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 12304917) with original publication details: Notes Roy. Bot. Gard. Edinburgh 16(79): 189–190 1931.
This name was in version 1 of The Plant List, record tro-12304917, and has not been changed.