This name is a synonym of Rhododendron dauricum var. ciliatum (Nakai) E.H. Wilson.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50054215) with original publication details: Bot. Mag. (Tokyo) 31: 241 1917.
This name was in version 1 of The Plant List, record tro-50054215, and has not been changed.