Mimulus ringens L.
Allegheny Monkey Flower
CC = 5
CW = -5
MOC = 46
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.
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.
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.
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.
Fruits - Capsules 9-12 mm long, ovoid to narrowly ellipsoid-ovoid.
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.
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).