Liatris aspera also known as the lacerate , rough , tall or prairie blazing star is a wildflower that is found the mid to eastern United States in habitats that range from mesic to dry prairie and dry savanna.
It grows to 2 - 4 feet. The flowers are an erect spike with numerous, purple, button-like, stalkless flower heads blooming from the top down. Leaves are alternate, numerous, rough, and narrow along the entire stem. It flowers from mid-August through September, with seed becoming ripe in October to November.
Synonym. — Eryngium yuccifolium Michx. Other common names. —Eryngium, eryngo, water eryngo, corn snakeroot, rattlesnake master, rattlesnake-weed, rattlesnake flag.
Eryngium yuccifolium Parsley Family - Apiaceae. The indians used this plant as a remedy for snakebite. Guess that's were it got it's name. It is also called: rattlesnake-master.