This name is a synonym of Rumex japonicus Houtt..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26002521) with original publication details: Candollea 12: 92–93, f. 1–2 1949.
This name was in version 1 of The Plant List, record tro-26002521, and has not been changed.