Smooth Ironweed
ExplorePlants
Smooth Ironweed
vernonia fasciculata
Smooth Ironweed is a robust and striking native North American perennial wildflower, famous for its vivid, intense purple blooms that emerge in late summer. Reaching heights of up to six feet, this resilient plant is a staple of wet prairies, sedge meadows, and river floodplains across the Midwestern United States. Its common name, ironweed, pays homage to its incredibly tough, fibrous stems, which successfully withstand strong prairie winds and discourage grazing animals. Gardeners and conservationists prize it for its ability to attract a wide diversity of pollinators, acting as an ecological anchor in tallgrass prairie restorations.
Habitat: Typically found in moist to wet prairies, marshes, sedge meadows, and river floodplains.
Appearance
This tall perennial stands upright on stiff, smooth, reddish-purple stems that are entirely hairless. Its lance-shaped leaves are arranged alternately, featuring sharply toothed margins and distinctive tiny pits on their hairless undersides. In late summer, the plant is topped by flat, dense clusters of bright magenta to deep purple flower heads, each composed entirely of disk florets with no rays, which eventually give way to rusty-brown seed heads.
KingdomPlantaePhylumTracheophytaClassMagnoliopsidaOrderAsteralesFamilyAsteraceaeGenusVernonia
Category
PlantsRarity
Common
Danger
1/5 · Very low
Snaps
Be the first to snap!
Interesting facts
Because livestock avoid its bitter taste, Smooth Ironweed often becomes dominant in overgrazed pastures, earning it a reputation as a stubborn weed among ranchers.
The common name 'Ironweed' refers not only to the tough, metallic-colored stems but also to the rusty-brown color of the seed heads in autumn.
The genus name Vernonia honors the English botanist William Vernon, who conducted extensive plant collections in Maryland during the late 17th century.
Special abilities
Ability
Wind Resistant Stems
The exceptionally tough, fibrous stems allow the plant to remain upright in severe storms and high prairie winds.
Ability
Grazer Deterrence
Leaves contain bitter chemical compounds that make the plant unpalatable to cattle and deer, ensuring its survival in heavily grazed areas.
Ability
Late-Season Nectar Provision
Blooms late in the season when many other flowers have faded, providing a critical nectar source for migrating butterflies.
Measurements & details
- Length
- 90-180 cm
- Lifespan
- 3-10 years
Diet & Feeding
As a photoautotrophic plant, Smooth Ironweed synthesizes its own food using sunlight, carbon dioxide, and water through the process of photosynthesis.
Primary Foods
- Sunlight
- Carbon dioxide
- Water
- Soil nutrients
Ecological connections
mutualism
Monarch Butterfly
Danaus plexippus
Provides vital late-season nectar to migrating adults during their southern journey.
eaten by
Ironweed Borer Moth
Papaipema impecuniosa
Larvae of this specialist moth bore into the stems of the plant to feed and pupate.
mutualism
Long-horned Bee
Melissodes dentiventris
Feeds heavily on the pollen and nectar, acting as an effective pollinator.
Traits
No trait badges are assigned for this object yet.
Also known as
No aliases listed yet.
Collections
Collections for this object will appear here as more themes are added.
Safety
Danger
1/5 · Very low
No special safety notes yet.
Frequently Asked Questions
How to identify Smooth Ironweed?
The easiest way to identify Smooth Ironweed is to use the Snappit nature identifier app.
How long is Smooth Ironweed?
90-180 cm
How long does Smooth Ironweed live?
3-10 years
What does Smooth Ironweed eat?
As a photoautotrophic plant, Smooth Ironweed synthesizes its own food using sunlight, carbon dioxide, and water through the process of photosynthesis.
Where is Smooth Ironweed usually found?
Typically found in moist to wet prairies, marshes, sedge meadows, and river floodplains.
Snap Map
Zoom in to split clusters and explore where this object has been snapped.
Loading map…
Recent Snaps
Recent snaps will appear here as new observations are added.
