This name is a synonym of Rhododendron kendrickii Nutt..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060207) with original publication details: Hooker's J. Bot. Kew Gard. Misc. 5: 360 1853.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:333343-1.
This name was in version 1 of The Plant List, record tro-50060207, and has not been changed.