("Gay feather / Blazing star")
Native to eastern & central North America, Mexico and the Bahamas.
Liatris like moist but well-drained soil (they definitely do not like clay). Do not plant them too deep and water well right after, then you can pretty much leave them alone. They are drought resistant and Winter-hardy and thus considered a perennial, so they can be left in the ground and will re-bloom year after year.