Vascular Plants of North Carolina
Account for Allegheny Monkey-flower - Mimulus ringens   L.
Members of Phrymaceae:
Members of Mimulus with account distribution info or public map:
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Section 6 » Order Scrophulariales » Family Phrymaceae
DistributionThroughout the Mountains and the Piedmont, though scarce in the southeastern portions (where locally absent), and possibly absent in the far northeastern counties. Ranges into the Coastal Plain only at a few isolated sites in the eastern portions.

This is a widespread species of North America, found south to central GA and OK, but scarce of the Coastal Plain.
AbundanceCommon in the Mountains and nearly all of the Piedmont, but seemingly rare to uncommon in the far southeastern corner of the Piedmont (Moore and Richmond counties). May also be very rare to absent in the far northeastern counties of the Piedmont (Halifax and Northampton). Very rare in the east-central Coastal Plain, at disjunct sites. This is clearly an S5 species (State Rank), not S4 as assigned by NCNHP.
HabitatThis is a wetland plant that grows along marsh edges, pond margins, in ditches, in openings in bottomlands, wet meadows, and bogs. These habitats overlap those of M. alatus, except this this species does not occur in the mountains (and thus not in bogs).
PhenologyBlooms from June to September, and fruits shortly after flowering.
IdentificationThis is an erect and moderately tall species, growing to about 2.5-3 feet tall. It has a square (4-sided) stem, but has no wings along the stem -- unlike the narrow wings on the stem of M. alatus. The several sets of leaves are opposite and mostly lanceolate in shape, very slightly serrated, but sessile to the stem. M. alatus has leaves with distinct petioles, leaves a bit wider, and leaves more strongly serrated on the margins. Each leaf is about 4 inches long and about 1-inch wide. The large flowers grow from the upper axils of the leaves, but in this species the flowers are on quite long stalks, each about 1-1.5 inches long. In the very similar M. alatus, the flowers are sessile. Each has lavender-blue flowers that resemble a snapdragon, each flower being about 1-long long or more (though the green sepals cover the corolla tube); the lower lip has some yellow in the throat. A stand of these species in bloom is quite showy and very hard to miss. Though their ranges overlap widely (essentially in the Piedmont), and the habitats seem to be identical, they seldom grow together in the same marsh or ditch. You should encounter each of these fairly often during the year; remember that M. alatus is the one with the sessile flowers but leaves that are not sessile; M. ringens -- the more dominant in the Piedmont (and the only one in the mountains) -- has the flowers on long stalks but the leaves are sessile. Also, M. ringens has essentially no wings along the 4-sided stem.
Taxonomic CommentsWeakley (2018) lists several varieties for this species, with the nominate one -- M. ringens var. ringens -- being the only one in NC.

Other Common Name(s)Squarestem Monkey-flower
State RankS4 [S5]
Global RankG5
State Status
US Status
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USACE-empOBL link
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Alicia JacksonFort Bragg, Cumberland County; 3 August 2019 CumberlandPhoto_natural
Alicia JacksonFort Bragg, Cumberland County; 3 August 2019 CumberlandPhoto_natural
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