This name is a synonym of Mimulus grandis (Greene) A. Heller.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50102046) with original publication details: J. Bot. 33(386): 7 1895.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:162247-2.
This name was in version 1 of The Plant List, record tro-50102046.