Joe-Pye Weed

Eupatorium maculatum.  Another member of the aster family.  Because it sometimes has spots it is commonly called Spotted Joe-pye Weed.

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This native species is well-adapted to wetter locations so it's often found in ditches, along stream banks and potholes.  The plants in the photos are growing in locations that are typically standing water in spring.

In case you are wondering about the odd name.  It comes from a medicine man named Joe Pye.

Butterflies love it.