At 1st glance looks like Brickellia eupatorioides. I beautiful native I just winter sowed seeds for.

I think it's Eupatorium serotinum, in the Joe Pye family. A super late-season flower for pollinators. Will get big if it's in the sun and happy, otherwise can stay fairly small in part sun or dry soil.

Fascinating! These two are quite similar. Considering more information, our plant was mildly fragrant and formed a close cluster of stems (actually beginning to emerge right now) - this seems to be more consistent with what we find for Eupatorium serotinum. Plus the flowers are pure white, not creamy. But open to more deliberation.

Ageratum?

It reminds me of the blue mistflower I have - a native that self seeds abundantly and has a heavenly scent - like sweet clover. Leaves are different, tho.

Yes, now that I look closer, I see some serated leaves, so it is Eupatorium serotinum, sorry about that. There are over 2000 species in the tribe Eupatorieae,(including Ageratum),and they all look similar, and identification gets especially difficult between the 31 Eupatorium species.