This name is a synonym of Rhododendron argyrophyllum subsp. nankingense (Cowan) D.F. Chamb..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060246) with original publication details: Notes Roy. Bot. Gard. Edinburgh 21(3): 148 1953.
This name was in version 1 of The Plant List, record tro-50060246, and has not been changed.