Ironweed (Vernonia fasciculata)
Family:  Asteracea
Hardiness:  to -40 degrees F
Herbaceous perennial to 5 feet tall, native to the midwestern and southern states, a prairie plant that still thrives in abandoned fields and wildlands.  Very showy, with flat-topped flowering crowns of bright purple.  Root considered by Native Americans to be a "blood tonic" for treating excessive menstrual bleeding and for reducing pain and bleeding after childbirth.  Plant prefers full sun and moist, even boggy soils.  Will compete very favorably with grasses and other forbs, establishing itself singly or in clusters.  To keep it from getting too tall (and they can sometimes even vie with gravel root flowers in terms of height, which is really pretty tall), then cut them back in early summer and they will substantially bush out.  These are pretty easy to grow and establish, and an excellent choice for any kind of open garden, naturalized, or prairie type setting.  Sow seed in spring, just under surface, tamp in, keep evenly moist until germination, and work up to sufficient size to plant to the open garden, which will probably take a couple of months or even can be grown out in gallon pots for a year and then transplanted to the landscape in the spring. 
Open Pollinated 50 seeds/pkt.