This name is a synonym of Rumex subarcticus Lepage.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50120984) with original publication details: Naturaliste Canad. 93(5): 546 1966.
This name was in version 1 of The Plant List, record tro-50120984, and has not been changed.