Common Ironweed (Vernonia fasciculata)
Common ironweed is a native perennial wildflower that adds vertical structure and late-season color to Wisconsin’s prairies and meadows. It typically grows up to six feet tall, with sturdy, unbranched stems that rise above surrounding vegetation. The leaves are dark green, alternate, and coarsely toothed, smooth on both sides and narrowly lance-shaped. Each leaf can reach up to five inches long and about half an inch wide.
In late summer, common ironweed bursts into bloom with dense clusters of small, tubular purple flowers at the tops of its stems. These vivid flower heads contain numerous disk florets and no ray florets, forming flat-topped arrangements known as corymbs. A corymb is a type of flower cluster in which individual flower stalks grow to different lengths, allowing all the flowers to reach roughly the same height and form a level surface. This structure creates a broad, showy landing pad for pollinators. Native bees, butterflies, and other beneficial insects flock to the blooms, making it a valuable nectar source when many other wildflowers have already faded. It also serves as a host plant for the American painted lady.
This plant is remarkably adaptable, tolerating a range of soil conditions from wet to dry and thriving in full sun to light shade. It is commonly found in moist meadows, open prairies, thickets, and fields, and is well-suited to rain gardens and restoration projects. Its seeds, equipped with fluffy bristles, disperse easily by wind, helping it establish in suitable habitats. (SF)