This name is a synonym of Ranunculus laxicaulis Darby.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 27101818) with original publication details: Bull. Torrey Bot. Club 27(5): 277 1900.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:217442-2.
This name was in version 1 of The Plant List, record tro-27101818, and has not been changed.