Hmmm...no fragrance...does not look like pinweed, the leaves appear to be fleshy but on the limp side if that makes sense. I did have a portulaca last year in a different bed and I just looked at the pix of it, and the leaves look the same except plumper. Maybe they will plump out as the weather warms? Guess I will leave it be for a while and see what happens. No other plant ANYWHERE near that looks like it, so thats why I think not weed.

Dzitmoidonc - YES! I found a photo and it matches perfectly. Whew! This morning I looked at it again and convinced myself it was a poison ivy or poison oak or some kind of poison something. And the squirrels in our neighborhood are NUTS (ha!) for those big walnuts, they drag them around all over the place. Mystery solved. Yay! Thanks everybody!

I agree that they appear to be suckers. They're probably all growing along a surface root. You can scrape away some of the grass and topsoil to see if it's even possible to move the with a sufficient amount of roots to survive. Usually suckers like this don't have a lot of roots of their own within a root ball. They're feeding off the larger structure.

Jay, I planted a very small tree there a couple years ago, but I think it was eaten and I didn't think it survived. I will let these live and keep an eye on them.