I'm thinking mine might be the 'swamp beggartick' rather than the 'devil's beggartick' variety. This webpage has good pictures and I need to go home and check some of these features. But it looks like a desirable, common, wildflower/bush that dresses up the pond nicely.

https://www.friendsofthewildflowergarden.org/pages/plants/swampbeggartick.html