This name is a synonym of Ranunculus eschscholtzii var. eximius (Greene) L.D. Benson.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 27103151) with original publication details: Erythea 3(2): 19–20 1895.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:217280-2.
This name was in version 1 of The Plant List, record tro-27103151, and has not been changed.