This name is a synonym of Rumex britannica L..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50079675) with original publication details: Manual (ed. 3) 377 1856.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:224443-2.
This name was in version 1 of The Plant List, record tro-50079675, and has not been changed.