Possibly Erechtites hieraciifolius, common names Pilewort, Burnweed, Fireweed (NOT the Fireweed with the beautiful big magenta flowers, that's an Epilobium). If it is Erechtites it's certainly weedy and I see one webpage about that lists it as invasive, but apparently it's a native pioneer species - likes bare disturbed ground. And it's an annual. I don't think it turns into the kind of problem a lot of 'invasives' do.

It does, however, let loose with hundreds of seeds per plant - I would pull them up, if I were you.

Thanks! The leaves seem similar to Solanum americanum.

https://identify.plantnet.org/observation/1000870090

No, it's not S americanum. Veination, texture, leaf margins, leaf petioles are all different.

I don't think that plant is Erechtites hieraciifolius. That species does have leaves with those scalloped margins and sharp teeth. However, the leaves are usually more elongated and typically clasp the stem.

I don't have a better suggestion for ID, though, so hope that you'll let at least one of them flower and then come back with more photos.

Good idea. I'll actually pot a couple of them for "research purposes",

Initially struck me as a Solanum but agree with others that flowers will give a great ID help.

Since we'll eventually know, once flowers are available, my guess is Physalis angulata (Cut-leaved Groundcherry).

If it is Erechtites, if you let it bloom, be aware that it doesn't have showy flowers. It goes from what looks like a tight bud directly to heads of fluffy white seeds (no way you can miss those.). When I said it wasn't as troublesome as some invasives I meant it doesn't develop a tuber as big as your arm while the plant is young, like Pokeweed, or throw runners that make a new plant every two inches, like everything else in my yard. And I don't think the seeds can take much competition - I usually see it in relatively bare ground, not in the middle of a bunch of other plants. It's variable, too. I think it looks more spiky as it gets bigger.

The flowers...

Oops.

Oh well, Solanum it is.

Most of it is Solanum, but there are one or two Erechtites tucked under the Solanum front and center.