This name is a synonym of Rhododendron keysii Nutt..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50064385) with original publication details: J. Roy. Hort. Soc. 59: xxxix 1934.
This name was in version 1 of The Plant List, record tro-50064385, and has not been changed.