This name is a synonym of Rumex thyrsiflorus Fingerh..
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Meddeland. Soc. Fauna Fl. Fenn. 25: 85 1900.
This name was in version 1 of The Plant List, record kew-2869527, and has not been changed.