Eupatorium nodiflorum

About

Eupatorium cannabinum, commonly known as hemp-agrimony, is a herbaceous plant in the family Asteraceae. It is a robust perennial native to Europe, Northwestern Africa, Turkey, Syria, Iran, Iraq, Jordan, the Caucasus and Central Asia, and grows in damp to wet habitats, usually in lowlands but known up to 410 m altitude in Britain. It is cultivated as an ornamental plant and occasionally found as a garden escape in scattered locations in China, the United States and Canada. It is extremely attractive to butterflies, much like buddleia.

Summary from Wikipedia