This name is a synonym of Rumex fueginus var. athrix (H. St. John) Rech. f..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50005134) with original publication details: Rhodora 17(196): 79 1915.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:224456-2.
This name was in version 1 of The Plant List, record tro-50005134.