Vernonia lettermannii 'Iron Butterfly', commonly known as Iron Butterfly Ironweed, is a compact, clump-forming perennial with narrow, thread-like green leaves and airy clusters of small, vivid purple flowers that bloom from late summer to early fall. Thriving in full sun and well-drained soil, this variety is perfect for borders, meadows, and pollinator gardens. 'Iron Butterfly' adds a fine, delicate texture and attracts pollinators, providing late-season color and interest.