This name is a synonym of Rumex cristatus subsp. kerneri (Borbás) Akeroyd & D.A.Webb.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Magyar Bot. Lapok 27: 73 1928 publ. 1929.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:696999-1.
This name was in version 1 of The Plant List, record kew-2424242, and has not been changed.