monkey flower, any of about 150 species of herbaceous or, rarely, shrubby plants of the lopseed family (Phrymaceae), all of which were formerly placed in a single genus Mimulus. The taxonomy of the group was thoroughly revised to better reflect evolutionary relationships, and many species were moved from Mimulus (now 7 species) to Erythranthe (111 species), Diplacus (46 species), and certain small genera. The plants are distributed worldwide but are particularly common in western North America. A number of species are cultivated as ornamentals for their attractive flowers.
Monkey flower plants have opposite, undivided leaves and solitary flowers with a two-lipped open corolla (fused petals). The flowers of some species are said to resemble a monkey’s face. The herbaceous species typically grow most abundantly in wet areas, usually near running water.