Mimulus rubellus is a diminutive annual herb with white and pink flowers with pink spots within the corolla tube. The corolla lobes are notched. The sessile leaves have one or two pairs of teeth or are entire. The calyx and herbage is stipitate glandular with sand and dirt readily sticking. Although this species is apparently more common in the mountains (as supported by specimens from the Pinos Altos area in the Dale A. Zimmerman Herbarium,) it can also found in the leaf cover under mesquite in the lower elevation arid areas after a moist winter.

Wiggins 1964, Kearney and Peebles 1969

Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Native annual herb; stems simple or loosely branched, with elongated internodes, 1-22 cm tall; glandular-hairy throughout, and often reddish. Leaves: Opposite, sessile (and often connate at the base), lanceolate to linear, 3-20 mm long, entire or nearly so. Flowers: Solitary from the leaf axils on stalks 7-20 mm long; calyx tubular, reddish-ribbed, 4-9 mm long, with ciliate teeth; corolla weakly two-lipped with the lips hardly spreading, 6-9 mm long, yellow with maroon dots, or often pinkish to violet. Fruits: Capsule 4-6.5 mm hlong, included in the persistent calyx. Ecology: Found in dry sites in shadscale, rabbitbrush, Joshua tree, catclaw, blackbrush, sagebrush, live oak, ephedra, pinon-juniper, and ponderosa pine commununties; 2,500-9,000 ft (762-2743 m); flowers February-April. Distribution: CA, NV, UT, AZ, WY, CO, NM, TX; south to n MEX. Notes: Usually a very tiny plant with a reddish tint and glandular-hairy all over with sessile, usually entire, opposite leaves and yellow to pink bi-labiate flowers. Ethnobotany: Leaves and stems were used as flavor enhancers. Juice of leaves make a soothing poultice for minor burns and skin irritations. Etymology: Mimulus means ape-flower, or a diminutive of the Latin minimus, a comic or mimic actor, because of the grinning corolla, while rube- is in reference to the color red. Synonyms: Mimulus gratioloides Editor: SBuckley 2010, FSCoburn 2015