This name is a synonym of Ranunculus aquatilis var. diffusus With..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 27100787) with original publication details: Mém. Soc. Roy. Sci. Nancy 1839: 39, f. 9 1840.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:217410-2.
This name was in version 1 of The Plant List, record tro-27100787.