This name is a synonym of Rumex aquaticus subsp. arcticus (Trautv.) Hiitonen.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Fl. Ochot. 29 1856.
This name was in version 1 of The Plant List, record kew-2424159, and has not been changed.