Description: This native perennial plant is 1-2½'
tall, branching occasionally. The stems are round and pubescent. The opposite
leaves are up to 3" long and 2" across, and have short petioles. They are
broadly lanceolate and hairless. Their margins are serrate or crenate, while
the upper surface is conspicuously veined. In bright sunlight, the leaves may
become yellowish green. The flowerheads occur in flat clusters at the top of
major stems. Each cluster of flowerheads spans about 1½–4" across.
Each flowerhead has about 50 tubular florets that are pink, lavender, or
blue-violet. A floret has 5 tiny lobes that flare outward, and a long exerted
style that is divided into two parts. The flowerheads are subtended by several
linear bracts that are light green and occur in 1 or 2 layers. The blooming
period occurs from mid- to late summer, and lasts about a month. Sometimes,
plants re-bloom during the fall under favorable weather conditions. There is no
noticeable floral scent. Achenes develop with small tufts of hair, which are
distributed by the wind. The root system is highly rhizomatous; this plant
readily forms colonies.
Cultivation:
The preference is moist soil, and light shade to full sun. There should be
sufficient organic material in the soil to retain moisture. This plant can
spread aggressively in moist open ground, otherwise it presents few problems.
Drought tolerance is poor.
Range &
Distribution: Mistflower occurs in the southern half of Illinois and
the Chicago area. It is fairly common in southern Illinois, but uncommon or
absent elsewhere. This plant was introduced into the Chicago area. Some local
populations in the
wild are probably the result of seeds or plants that have escaped cultivation.
Habitats include riverbottom prairies, moist open woodlands, gravelly seeps,
borders of lakes and rivers, moist meadows in wooded areas, the base of bluffs,
and roadside ditches. This plant usually occurs in poorly drained areas and
near sources of water.
Faunal
Associations: The flowers attract long-tongued bees, butterflies,
and skippers. Other occasional visitors include short-tongued Halictid bees,
various flies, day-flying moths, and Soldier beetles. These insects seek nectar
primarily, although the bees often collect pollen. The caterpillars of several
moth species feed on various parts of this and other Eupatorium spp.,
including Haploa clymene (Clymene Moth; eats foliage), Phragmatobia
lineata (Lined Ruby Tiger Moth; eats foliage), Carmenta bassiformis
(Eupatorium Borer Moth; bores into roots), and Schinia trifascia
(Three-Lined Flower Moth; eats flowers & seed capsules). Mammalian
herbivores rarely consume this plant because of the bitter
foliage.
Photographic Location: The
photograph was taken along a drainage ditch at Kaufman Lake Park in Champaign,
Illinois.
Comments: Mistflower has
attractive, delicate flowers, often in interesting shades of pink, lavender, of
blue. For this reason, it is often grown in flower gardens. This plant is
closely related to the white-flowered Bonesets (Eupatorium spp.), and is
often referred to as Eupatorium coelestinum. Mistflower can be
distinguished from the Bonesets primarily by its colorful flowers, relatively
short stature, and broad opposite leaves that are heavily veined. While the
Joe-Pye Weeds (Eupatoriadelphus spp.) have colorful flowers, they are
taller plants with whorled leaves.