This perennial wildflower is ½-2' tall. The erect central stem is light
green to reddish purple, 4-angled, and glabrous (or nearly so); it is
unbranched or sparingly so along the upper half of its length. Pairs of
opposite leaves occur at intervals along each stem. These leaves are
¾-1¾" long, ½-1" across, ovate, and coarsely dentate, becoming only
slightly smaller as they ascend each stem. The upper surface of the
leaves is medium green, slightly indented along the veins, and
glabrous, while their lower surface is pale to medium green and either
glabrous or slightly hairy along the lower sides of the veins. Leaf
venation is pinnate with 4-6 lateral veins on each side of the midrib.
The leaves are nearly sessile or they have short petioles up to
¼" long. The foliage of Red Mint has a strong spearmint fragrance.
Dense whorls of nearly sessile flowers occur above the middle
upper leaves along a stem; these inflorescences are non-terminal and
they do not extend beyond the middle of these leaves. Individual
flowers are about 1/8" in length, consisting of a white to light pink
corolla with 4 lobes, a short green or reddish green calyx with 5
narrowly lanceolate teeth, either 4 or no stamens (usually the latter),
and either 1 or no pistil with a single style. Some reproductive organs
are often missing from the flowers because this hybrid mint is sterile.
The calyx of each flower is glabrous, except along the teeth, where it
is sometimes ciliate. The very short pedicels of the flowers are
blooming period occurs from mid-summer into the early fall for about
1-2 months. Above the whorled flowers of plants in bloom,
there are often pairs of opposite leaves that are without developed
flowers. Because the flowers are sterile, fertile nutlets are not
normally produced. The shallow root system is fibrous and rhizomatous.
This wildflower reproduces vegetatively by forming clonal offsets from
the rhizomes. As a result, dense
colonies of plants are often formed.
The preference is full or partial sun, moist conditions, and fertile
loamy soil. This wildflower is easy to cultivate, but it can spread
aggressively by means of its rhizomes.
& Habitat: The
introduced Red Mint occurs across scattered counties in primarily
and northern Illinois; it is uncommon as a
naturalized plant within the state. Red Mint was introduced from Europe
as a culinary and medicinal herb; it is also somewhat ornamental in
Habitats consist of grassy or sedgy sloughs, low areas along rivers,
damp weedy meadows, roadside ditches, edges of yards, and vacant lots.
Areas with a history of disturbance are preferred. This mint is
sometimes cultivated in gardens under various names.
Associations: Like other mints (Mentha spp.), the
Red Mint attract small bees, wasps, flies, small butterflies, and
skippers; these insect suck nectar primarily. Other insects
feed on the foliage and other parts of mints. These insect feeders
include the caterpillars of such moths as Agriopodes teratophora
Gray Marvel), Haploa
lecontei (LeConte's Haploa), Pyrausta acrionalis
(Mint-Loving Pyrausta), and Sphinx
eremitus (Hermit Sphinx); the leaf
gibbitarsa and Longitarsus
ferrugineus (Clark et
al., 2004); the stink bugs Cosmopepla lintneriana
and Coenus delius;
larvae of the gall fly Giardomyia
piperitae; and Chortophaga
viridifasciata (Northern Green-Striped Grasshopper).
animals dislike the strong-scented foliage of mints and usually avoid
them as food plants, although the Ruffed Grouse has been known to feed
on their foliage (Bennetts, 1900).
Location: A weedy slough that was too wet to be mowed
during most of
the year. At this slough, a sizable colony of plants was found
near Champaign, Illinois.
Another common name of Mentha
× gentilis is Little-Leaved Mint. In addition
to the usual Mentha spp.
(mints), several hybrid mints have
described by various authorities. As a group, these hybrid mints are
very difficult to identify and their taxonomy is problematic,
notwithstanding numerous revisions through the years. Like some other
hybrid mints, Red Mint is a presumed hybrid of Mentha arvensis
Mint) and Mentha spicata
(Spearmint). Of these two parents, Red Mint
has more characteristics in common with Spearmint than Field Mint
(e.g., hairless foliage). However, Red Mint could be a more complex
hybrid involving a third Mentha
sp. (unidentified mint) as a parent.
These days, the majority of taxonomists have grouped together formerly
distinct hybrids into a single variable hybrid, Mentha × gracilis
(Ginger Mint). Thus, such mint hybrids as Mentha × cardiaca, Mentha ×
× rubra, etc. are now considered variants of
Mentha × gracilis
(Ginger Mint). However, because
variations in leaf shape and size, hairiness of stems and leaves,
hairiness of calyces, and other characteristics among these mints, this
taxonomic approach has not been adopted here.