Yarrow?

Here is a link that might be useful: The Yarrow plant

That sure does look like it saltcedar! Thank you so much for the link. I think I will leave and watch it. I've been trying to figure out what to do with this particular flowerbed, so if it grows well there then I might have an answer!

Or maybe Poison hemlock, Conium maculatum, or possibly Queen Anne's lace, Daucus carota.

You may have to wait until it blooms to know for sure.

Thank you Dave. I think I've ruled out poison hemlock based on close up photos of the leaves, but Queen Anne's lace is a possibility.

Odds are it's yarrow.

I've grown lots of yarrow and that is what I would say it is. It is a nice herb (medicinal) and has a pretty flower. They tend to do well in not so great (hard & dry) locations so unless you have something else to plant there, I would personally leave it. Just take out what is in the way.

FataMorgana

Yarrow.