This name is a synonym of Rumex densiflorus Osterh..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50079661) with original publication details: Pittonia 4(25A): 305 1901.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:224487-2.
This name was in version 1 of The Plant List, record tro-50079661.