Might be Senecio (now Packera?), common name is ragwort (which is not ragweed).

I don't think it's ragwort... Here is a better picture. This plant has several separate stems, rather than a central stem.

Really need a better picture, I'm afraid. Unless someone recognises it straight off from the overall impression we need to see details of the flowers and leaves. At the moment I can't even see if it is Asteraceae or Brassicaceae or what.

That may be Senecio vulgaris, an invasive species in the South.

Definetely not Sen vulgaris

And yes, like floral said, not even clear which familia at all

Epazote?

Here is a link that might be useful: Dysphania ambrosioides

I'm sorry. I still haven't perfected how to post pictures. This one should be better. The leaves are alternate. The flowers look like broccoli or cauliflower florets and don't seem like they will bloom. The plant hasn't gotten any taller, but it is now starting to form almost succulent-type leaves that look like small bananas at the top. Whatever it is, it is attracting a lot of pollinators. Any additional ideas?

Don't know what that weed is, but I'd remove it before it forms seed.

Those 'bananas' are seed pods. They make it pretty likely that your plant is in the Brassicaceae. If you split one with your fingernail you'll see immature seed. I'd pull it up before you have mature seed. If you are still interested in an id you could grow one in a pot.

Looks like leafy spurge. I'm in your same zone and it's invasive whatever the name. Comes up like gangbusters. Loves to take over. That center stalk just gets stronger the longer you leave it, but not necessarily much taller. Soon you'll have a forest of plants like that with a root system to Texas.
Heidi in Nebraska

It's not a Euphorbia. The colouring is similar but the flowers, leaves and seedpods don't fit.

Thank you, Everyone! I had hoped it was something worth keeping, but I will dig it up and get rid of it before it spreads. On the bright side: I need that space anyway to make room for some asparagus. :-)