Rigid Goldenrod
Oligoneuron riddellii
Notes:
From what I've read, Goldenrods are one of the best caterpillar host plants. In the photos, you can see they are also popular with the adult pollinators.
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Photos:
Till now man has been up against Nature; from now on he will be up against his own nature.
Dennis Gabor
Inventing the Future, 1964