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. Arct. URSS 158 1966.
This name was in version 1 of The Plant List, record kew-2869531, and has not been changed.