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 27101520) with original publication details: Amer. Midl. Naturalist 40(1): 236 1948.
This name was in version 1 of The Plant List, record tro-27101520.