Any of about 500 species of perennial plants constituting the genus Vernonia (family Asteraceae).
Small herbaceous (nonwoody) species are found throughout the world; shrubs and trees are found primarily in tropical regions. Ironweed species have lance-shaped, toothed leaves that alternate along the stem; clusters of flower heads composed only of disk flowers (no ray flowers); and a ring of overlapping bracts below the flower heads. Some autumn-blooming species are cultivated as border plants for their attractive white, purple, or pink flower clusters.
Western ironweed ( Vernonia fasciculata )
Dan Morrill