This name is a synonym of Rhododendron rigidum Franch..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 12303853) with original publication details: Gartenflora 57: 561, pl. 1577 1908.
This name was in version 1 of The Plant List, record tro-12303853, and has not been changed.