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 50060754) with original publication details: Monogr. Azaleas 62 1921.
This name was in version 1 of The Plant List, record tro-50060754, and has not been changed.