Ironweed, a genus of tall, coarse herbs. About 10 species grow wild along roadsides and in neglected fields of the eastern and southern United States. The plant is named for its hard stem. Some species grow as tall as 10 feet (3 m). The slender, tooth-edged leaves grow alternately on the stems. Broad, flat clusters of purple, or occasionally white, flowers appear in late summer.

New York ironweed is Vernonia noveboracensis; tall ironweed, V. altissima. Ironweed belongs to the composite family, Compositae.