This name is a synonym of Rhododendron orbiculare subsp. cardiobasis (Sleumer) D.F. Chamb..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060090) with original publication details: Notizbl. Bot. Gart. Berlin-Dahlem 12: 484 1935.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:332111-1.
This name was in version 1 of The Plant List, record tro-50060090, and has not been changed.