This name is a synonym of Rumex conglomeratus Murray.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26001150) with original publication details: Spic. Fl. Lips. 155, nr. 300 1771.
This name was in version 1 of The Plant List, record tro-26001150, and has not been changed.