Found in SW lower Michigan, September 16. The plants were growing in sandy soil on the bank of a lake/large pond. I'm not sure if this is a flower that's done blooming, just about to bloom, or in full bloom - like Bidens vulgata, but the flowers and the leaves don't really match up. If it's an unopened flower it seems kind of late in the season for that, although the leaves do seem to ressemble Bidens aristosa but I have photos of it with partially opened flowers and those don't seem to look like this plant.