This is Ageratina altissima, also known as Chocolate Joe Pye Weed, white snakeroot, richweed, white sanicle, and tall boneset. This plant is a nectar source for the Eastern Tiger Swallowtail, Gold-bordered Hairstreak, Antillean Daggerwing, Giant White, and Florida White butterflies. This is also a Larval host plant for the Eupatorium Borer, Agonopterix eupatoriiella, Agonopterix atrodorsella, and Clymene Moths. USDA Hardiness Zones 5 to 8.