Vernonia gigantea

tall ironweed, giant ironweed
Family

Asteraceae

Leaf Arrangement

alternate, basal (rosulate)

Leaf Attachment

petiolate

Leaf Margin

entire, serrate

Leaf Type

simple

Leaf Shape

elliptic, lanceolate, ovate

Growth Form

forb

Flower Color

pink, purple, white

Flower Month

June - November

Height (meters)

1.0 - 3.0

Milky Sap

No

Armed/Unarmed

Unarmed

Origin

native

Lifespan

perennial

Growing Season

Warm season


Wetland Class

FAC

Prairie Coefficient of Conservatism

5

Field Characters

Very similar to V. texana which also has short, straight conical projections on the lower leaf surfaces, and occasionally patches of longer curly hairs along the veins. They can be distinguished by their leaves which are lanceolate to elliptic-lanceolate in V. gigantea and linear to lance-linear (sometimes mistaken for Helianthus angustifolius) in V. texana. Stem hairy and leaves have sharp teeth, each with a white tip. Leaves also hairy.

Animal Use

Tough and bitter, not palatable to cattle.

Natural History

The genus name Vernonia is in honor of William Vernon, an English botanist of the early 1700s. The common name "ironweed" probably refers to its toughness.

Habitat

Moist or wet woods, and in coastal prairie.