Leggy, white wildflower that grows in fields and disturbed areas. Prolific bloomer in September and October in my part of the world. Bonesets can be hard to tell apart ... the leaves are the best indicator.
Also called Late thoroughwort.
The delicate flowers of Late Boneset closely resemble the flowers of other Bonesets, such as Eupatorium altissimum (Tall Boneset) and Eupatorium perfoliatum (Common Boneset), in both color and structure. These Bonesets can be distinguished readily from each other by an examination and comparison of their leaves. Tall Boneset has leaves that are pubescent, more narrow, and less coarsely serrated than Late Boneset, while Common Boneset has leaves that wrap around the stem and are without petioles.
Also similar to False boneset ... not surprising.