This name is a synonym of Rumex dentatus subsp. halacsyi (Rech.) Rech.f..
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Verh. K. K. Zool.-Bot. Ges. Wien 49: 105 1899.
This name was in version 1 of The Plant List, record kew-2424060, and has not been changed.