This name is a synonym of Rhododendron roxieanum var. cucullatum (Hand.-Mazz.) D.F. Chamb..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060389) with original publication details: Akad. Wiss. Wien, Math.-Naturwiss. Kl., Anz. 58: 26 1921.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:332270-1.
This name was in version 1 of The Plant List, record tro-50060389, and has not been changed.