I've been wanting to figure out that one too. I don't have any great pics of it, unfortunately. It's very tall for me - all of 4 feet, and grows into the hydrangea next to it or flops in the weeds. I should cut it back early so it can stand better on its own, but I never remember to do that. Here are a couple of poor pictures I have. Neither are in bright sunlight so mine looks darker than yours.
Flopping everywhere
Flopping everywhere
