This name is a synonym of Rhododendron irroratum subsp. pogonostylum (Balf. f. & W.W. Sm.) D.F. Chamb..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50060199) with original publication details: Trans. Bot. Soc. Edinburgh 27(2): 210–214 1917.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:333104-1.
This name was in version 1 of The Plant List, record tro-50060199, and has not been changed.