This name is a synonym of Rumex hastatus D. Don.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50136006) with original publication details: Bull. Géogr. Bot. 22: 228 1912.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:697053-1.
This name was in version 1 of The Plant List, record tro-50136006, and has not been changed.