This name is a synonym of Rhododendron indicum (L.) Sweet.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060809) with original publication details: Bot. Mag. (Tokyo) 29: 261 1915.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:332543-1.
This name was in version 1 of The Plant List, record tro-50060809.