Joe Pye Weed
Joe pye weed (Eupatorium maculatum)
Inflorescence of Eupatorium maculatum. Note the relative flat shape of the inflorescence. This is an easy way to distinguish between E. maculatum and E. purpureum (along with E. fistulosum) which are much more conical or dome-shaped. Also, E. maculatum is generally in a much wetter environment than E. purpureum which grows in drier environments.