I found this cup plant (Silphium perfoliatum, Asteraceae) noteworthy because of the interesting leaf arrangement. The broad, opposite, coarsely toothed leaves come together at the stem in a cup shape (presumably what gives it its common name):
The flower is your standard yellow composite:
According to the USDA, this is a threatened species in Michigan. To me, that makes it a cool find. At the same time, it’s apparently listed as an invasive/banned weed in Connecticut.