This name is a synonym of Mimulus subuniflorus (Hook. & Arn.) Jeps..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50102646) with original publication details: Bot. Beechey Voy. 378 1841.
This name was in version 1 of The Plant List, record tro-50102646, and has not been changed.