ironweed

Any of various plants of the genus Vernonia of the composite family, having alternate leaves and clusters of purplish flower heads.

Same as flattop.

Also, any of the species of the genus Vernonia, handsome composite plants of North America. See Vernonia.

The blue vervain, Verbena hastata.

The black knapweed, Centaurea nigra. Also called ironhead.

A tall weed with purplish flowers (Vernonia Noveboracensis). The name is also applied to other plants of the same genus.

Any of certain species of the genus Vernonia of forbs and shrubs.

any of various plants of the genus Vernonia of tropical and warm regions of especially North America that take their name from their loose heads of purple to rose flowers that quickly take on a rusty hue