What plant - palmate leaves, very irregular margins

This is so untimely a posting, from two years ago in May, but I saw the plant I'm questioning at a garden recently and then it just showed up today in a Maples posting, so now I want to know what it is. The one in front, which has not been posted in this subforum, is Eomecon chionantha, shown in the second photo with its own leaves below the flowers. That's in the Papaveraceae family, and it is the subject of a Botany Photo of the Day: Eomecon chionantha - Botany Photo of the Day

The one I'd like the name for is the one behind it. I might even have known the name once.

 

It's another Papaveraceae species, Macleaya microcarpa.

 

Thanks, Eric. The name sounds familiar, but at least it's not one I've posted.