Ironweed (vernonia noveboracensis) is a perennial forb or herb. This plant is native to the United States and has its most active growth period over the summer. It has dark green foliage and conspicuous purple flowers. The best blooms are observed in late summer. Ironweed has a short lifespan relative to most other plant species and a moderate growth rate. Once mature, it can reach a height of 6.6 feet.