Prairie ironweed
Vernonia fasciculata
A tall, clump-forming North American prairie perennial topped in late summer by broad, flat clusters of intense red-purple flowers. Native to the moist tallgrass prairies, wet meadows, and streambanks of the central United States and prairie Canada, it stands 3-6 feet on stiff, unbranched stems and demands full sun with consistently moist soil. Its late-season nectar makes it an outstanding pollinator plant — a fueling stop for monarchs heading south and a magnet for native bees and butterflies when little else is blooming.
Native: 17 US states + 2 CA provinces
Climate fit: moderate (69/100)
Pollinator
Structure
Light
Full sun
Water
Consistent moisture
Mature size
36-72" tall · 24" apart
Hardy in zones
3a-7b
brutally cold to cold winters
Native in Illinois
Yes
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Native across 19 US states and Canadian provinces — a wide-ranging part of North America's plant communities.
Cold hardiness
These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.
Now
Zone 6b
Plotwright
USDA Zone 6b
-5°F to 0°F
Well-suited
Zone 7a
Plotwright
0°F to 5°F
Well-suited
In plain terms: This location has cold winters. Its winters are projected to keep warming through 2050.
✓
Well-suited today and still thriving in 2050.
Heat tolerance
Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.
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Where this plant fits
Suitable across 34 ecoregions — 26 climate-resilient through 2070 · 8 suited today. Best matches first.
Appalachian mixed mesophytic forests
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Appalachian-Blue Ridge forests
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Arizona Mountains forests
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Blue Mountains forests
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Canadian Aspen forests and parklands
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Central Tallgrass prairie
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Central-Southern Cascades Forests
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Colorado Rockies forests
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Cross-Timbers savanna-woodland
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Eastern Canadian Forest-Boreal transition
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Similar plants
Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.
Eupatorium perfoliatum
Boneset
A large, hairy, clump-forming North American native perennial of wet meadows, low woods, stream banks, and prairies. Its most distinctive feature is the perfoliate foliage — pairs of wrinkled, opposite, lance-shaped leaves whose bases fuse around the hairy stem, so the stem appears to pass through the leaf. From July to September, flat-topped clusters of small, fluffy white flowers feed a wide range of bees, butterflies, and other pollinators, while all parts of the plant are toxic and bitter.
Passiflora incarnata
Maypop (purple passionflower)
A fast-growing, tendril-climbing native vine of the eastern United States, named "maypop" for the fleshy egg-shaped fruits that pop underfoot. Its intricate 2.5-inch fringed flowers — white-to-lavender petals beneath a pinkish-purple filament crown and a raised central androgynophore — are precisely engineered for large carpenter bees. Woody in warm-winter climates and herbaceous (dying to the ground) where winters are cold, it climbs to 6-8 feet on a trellis and produces edible yellowish maypops in fall.
Helianthus tuberosus
Sunchoke
A tall, tuber-forming perennial sunflower native to eastern North America — also called Jerusalem artichoke or sunroot — grown both for its 2-4 inch bright-yellow late-summer sunflowers and its knobby edible underground tubers. Rough-hairy stems rise 6-10 feet bearing ovate, serrate leaves on winged petioles. It spreads aggressively by rhizome and self-seeding to form colonies; Missouri Botanical Garden flatly calls it "weedy and invasive" and difficult to remove once planted.
Eutrochium purpureum
Sweet Joe-Pye weed
A tall native perennial wildflower of moist meadows and woodland edges across eastern North America, producing large domed clusters of vanilla-scented pink-purple flowers in late summer — among the most reliable late-season nectar sources for monarchs, swallowtails, skippers, and native bees. Formerly classified as Eupatorium purpureum.
Senna hebecarpa
Wild senna
A tall, clump-forming native legume of eastern North America grown for showy mid- to late-summer clusters of gold-yellow flowers accented by dark, curving anthers. The pinnately compound leaves carry a club-shaped gland on the petiole, and the long-lived plants reach 4-6 feet. Bumblebees work the pollen-only flowers, hummingbirds visit, and the seeds feed birds including bobwhites.
Baptisia australis
Blue false indigo
A long-lived native perennial of central and eastern US woodland borders and prairie meadows with deep blue pea-shaped flowers in late spring, blue-green leguminous foliage, attractive black seed pods for winter interest, and a nitrogen-fixing root system (Fabaceae). Larval host for 6 documented butterfly species per NC State (orange sulphur, clouded sulphur, frosted elfin, eastern tailed-blue, hoary edge, wild indigo duskywing) — among the highest Lep-host-count perennials in the eastern flora.
Sources & citations
Cite this page
For lesson plans, articles, or research that uses this page. To cite a single upstream fact instead, use its specific source listed below.
Plotwright. (2026, May 17). Prairie ironweed (Vernonia fasciculata). Retrieved 2026, June 24, from https://plotwright.com/plants/vernonia-fasciculata
Sources for every fact
Every fact on this page traces to a source. 18 fields cited - 18 source-backed.
GBIF
Botanical research database
Backs 17 fields
Identity
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