This came up in my garden. At first I thought it was a weed but it had interesting leaves so I left it. Now it has these interesting blooms. I don't remember planting anything like this but I have MS and easily forget.
Can you help me?

Polygonum pennsylvanicum Japanese knot weed

https://www.google.com/webhp?s...

I was thinking lady's thumb because of the dark patches on the leaves:

I hope you really like it because you'll have plenty of it soon. Just spent an hour pulling it out of my lawn.

oh dear! I was afraid of that! Thank you everybody for your responses!