This name is a synonym of Rhododendron concinnum Hemsl..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 12303895) with original publication details: The Species of Rhododendron 783 1930.
This name was in version 1 of The Plant List, record tro-12303895, and has not been changed.