This name is a synonym of Rorippa clandestina var. sodiroi (O.E. Schulz) J.F. Macbr..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 4104560) with original publication details: Repert. Spec. Nov. Regni Veg. 33: 277 1934.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:167287-2.
This name was in version 1 of The Plant List, record tro-4104560, and has not been changed.