Joe Pye Weed
Joe pye weed (Eupatorium maculatum)
Close up (not a great one, sorry) of the flowers of Eupatorium maculatum. One of the big differences between this and E. purpureum (along with E. fistulosum), are the number of florets per involucre (flowerhead). If you magnify this photo you can count approximately 10 florets or more per involucre. In E. purpureum there are between 4-7. This is not an obscure reference, the individual flowers can pretty easily be counted by rolling an involucre between fingers to separate the individual flowers, or just count while they are in the involucre. For other differences between these, see other Eupatorium photos.