This name is a synonym of Mimulus primuloides subsp. linearifolius (A.L. Grant) Munz.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50084319) with original publication details: Ann. Missouri Bot. Gard. 11(2–3): 246–247 1924.
This name was in version 1 of The Plant List, record tro-50084319.