This name is a synonym of Rhododendron pulchrum Sweet.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060753) with original publication details: Gen. Hist. 3: 845 1834.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:60457369-2.
This name was in version 1 of The Plant List, record tro-50060753, and has not been changed.