This name is a synonym of Rhododendron neriiflorum var. agetum (Balf. f. & Forrest) T.L. Ming.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060497) with original publication details: Sp. Rhodod. 533 1930.
This name was in version 1 of The Plant List, record tro-50060497, and has not been changed.