Mimulus ringens L.

Allegheny Monkey Flower

© DETenaglia

Family - Phrymaceae

Habit - Perennial forb from fibrous roots, often with rhizomes or stolons.

Stems - Strongly ascending to erect, to 1.3 m, single or multiple from base, usually branched above, glabrous, 4-angled, the angles sometimes narrowly winged, the wings often poorly developed.

	Stem and node.
© SRTurner

Leaves - Opposite, simple, sessile, clasping. Blades 4-14 cm long (the uppermost often shorter and bractlike), 3-7 times as long as wide, narrowly oblong to oblong-lanceolate or narrowly oblong-obovate, broadly angled to rounded at the base, angled or tapered to a sharply pointed tip, the margins relatively bluntly and finely toothed or scalloped, the surfaces glabrous, the venation pinnate.

	Stem and leaves.
© SRTurner

	Leaf adaxial. Leaves are sessile and often clasping.
© SRTurner

	Leaf abaxial.
© SRTurner

	Pressed leaves.
© DETenaglia

Inflorescence - Solitary axillary flowers, appearing 2 per node, lacking additional bracts and bractlets. Flower stalks 15-40 mm long, elongating to 20-60 mm at fruiting, glabrous.

	Inflorescence.
© SRTurner

Flowers - Calyces 10-17 mm long, nearly actinomorphic, narrowly funnelform, the 5 lobes 2.5-8.0 mm long, triangular to broadly triangular, the thickened midrib of each sepal often extending past the body of the lobe as a short, stiff, straight awn, glabrous externally. Corollas zygomorphic, bilabiate, 20-40 mm long, light blue to purplish blue, finely glandular-hairy, the upper lip smaller, 2-lobed, usually strongly curved or bent outward, the lower lip larger, 3-lobed, with a pale yellow area toward the base, this red-or brownish red-spotted, the throat usually appearing more or less closed by the prominent, blunt ridges ("palate") of the lower lip. Stamens 4, didynamous, included. Filaments white, glabrous, adnate at middle of corolla tube. Anthers 2 mm broad. Style 1.3 cm long, white, glabrous. Stigma flattened, suborbicular. Ovary superior, green, glabrous, conic, 5 mm long, 2 mm in diameter, 2-locular. Placentation axile. Ovules numerous.

	Flower. Note long pedicel.
© SRTurner

	Calyx.
© SRTurner

	Corolla.
© DETenaglia

	Corolla.
© SRTurner

	Corolla.
© SRTurner

Fruits - Capsules 9-12 mm long, ovoid to narrowly ellipsoid-ovoid.

	Immature fruits.
© SRTurner

Flowering - June - September.

Habitat - Streambanks, pond margins, sloughs, oxbows, fens, swamps, bottomland forests, ditches.

Origin - Native to the U.S.

Lookalikes - M. alatus.

Other info. - This plant occurs in scattered form throughout much of Missouri, and also occurs across the northeastern quadrant of the continental U.S. and into Canada. Plants are easily identified to genus by the distinctive lavender-colored flowers having a smaller upper and larger lower lip. This particular species is characterized by long flower stalks and by leaves which are sessile and clasping. Pure examples are easily recognized; however, the species readily crosses with M. alatus, which often grows in the same area, and this gives rise to morphologically intermediate forms which may be difficult to characterize. All Missouri monkey flowers grow in moist or wet areas.

Steyermark divided the species into two varieties, with var. ringens as described above, and variety minthodes (Greene) Grant having leaves which taper to the base and do not clasp. The latter form probably represents a hybrid with M. alatus and is thus more properly termed Mimulus xminthodes Greene.

The common term "monkey flower" is a somewhat cryptic allusion to the similarity of the flower to a simian face. This similarity is also responsible for the genus Mimulus, which is derived from the Latin mimus ("mimic"). The specific epithet ringens means "open mouthed," once again referring to the flowers. The plant is appropriate for gardening in wet places, and is available from native plant nurseries.

Photographs taken in Ellington, MO., 7-13-03 (DETenaglia); also at Holly Ridge Conservation Area, Stoddard County, MO, 8-15-2009, in Fremont, Newaygo County, MI, 7-2-2014, and at Riverfront Park, Washington, Franklin County, MO, 7-12-2020 (SRTurner).