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 50054466) with original publication details: Nuovo Giorn. Bot. Ital., n.s., 17(2): 260–261, f. 4 1910.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:696975-1.
This name was in version 1 of The Plant List, record tro-50054466, and has not been changed.