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Vernonia gigantea (Giant ironweed)
Smith, R.W.

Vernonia gigantea

Vernonia gigantea (Walter) Trel.

Giant Ironweed, Tall Ironweed

Asteraceae (Aster Family)



USDA Native Status: L48 (N), CAN (N)

Tall erect stem bears deep purple-blue flower heads in loose terminal clusters.

The common name refers to the toughness of the stem. The genus name honors the English botanist William Vernon, who did fieldwork in North America. At least 6 additional species are found in the East; some were once used for treating stomach ailments.


From the Image Gallery

12 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Size Notes: Up to about 10 feet tall.
Fruit: Fruit is a cypsela (pl. cypselae). Though technically incorrect, the fruit is often referred to as an achene.

Bloom Information

Bloom Color: Purple
Bloom Time: Jun , Jul , Aug , Sep , Oct


USA: AL , AR , DE , FL , GA , IA , IL , IN , KS , KY , LA , MD , MI , MO , MS , NC , NY , OH , OK , PA , SC , TN , TX , VA , WV
Canada: ON
Native Distribution: New York south to Georgia; west to Louisiana; north to Missouri, Illinois, and Michigan.
Native Habitat: Damp, rich soil.

Growing Conditions

Light Requirement: Sun , Part Shade , Shade
Soil Moisture: Moist
Conditions Comments: Very adaptable, hardy.


Use Wildlife: Bees
Conspicuous Flowers: yes

Value to Beneficial Insects

Special Value to Native Bees

This information was provided by the Pollinator Program at The Xerces Society for Invertebrate Conservation.

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Mt. Cuba Center - Hockessin, DE

Web Reference

Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Vernonia gigantea in USDA Plants
FNA: Find Vernonia gigantea in the Flora of North America (if available)
Google: Search Google for Vernonia gigantea


Record Modified: 2023-01-30
Research By: TWC Staff

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