This name is a synonym of Rhododendron irroratum Franch..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060197) with original publication details: Akad. Wiss. Wien, Math.-Naturwiss. Kl., Anz. 57: 288 1920.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:332957-1.
This name was in version 1 of The Plant List, record tro-50060197.