Not Zizia. Do the leaves have a scent when rubbed?

I think it's Ageratina altissima. That explains why the deer leave it alone. They have small white flowers in late summer that light up in the early evening. They produce many seeds, and can be a nuisance. Zizia would do well there. Zizia aurea,(Golden Alexanders,is a prolific self seeder also. Zizia aptera, ( Heart Leaved Golden Alexanders), isn't as rambunctious as Z. aurea.

Oh yes! It's definitely Ageratina altissima. I don't know why I didn't think of that because they are all over the back woods in late summer.

So, Rorry, you already know how it can spread everywhere Lol. White Snakeroot forms dense, monoculture stands, just like Canada Goldenrod, but it only spread by seeds, and not rhizomes. . If you like the look of Zizia, you might like some other native Apiaceae with compound leaves. There is, Cryptotaenia canadensis, Taenidia integerrima, and the delicate, ferny Osmorhiza claytonii and Osmorhiza longistylis. A lot of things look great growing next to a snag/stump in part shade.