This name is a synonym of Ranunculus reptans var. flagellifolius (Nakai) Ohwi.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 27104970) with original publication details: Bot. Mag. (Tokyo) 42(493): 24 1928.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:712723-1.
This name was in version 1 of The Plant List, record tro-27104970, and has not been changed.