This name is a synonym of Rumex ellipticus Greene.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26001316) with original publication details: Taxon 35(3): 612 1986.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:952699-1.
This name was in version 1 of The Plant List, record tro-26001316, and has not been changed.