THANK YOU to all who have helped me identify a few plants. The ragweed and others are now pulled out of my orchard, and the trumpet vine is no longer threatening the house foundation or the neighboring herbs. I left some purslane in a few areas and I'll try nibbling on it.
Now for a new one. We have an open space with freshly dug dirt and I noticed a plant today that I've never seen before. It looks "purposeful" if that's a term, but I have no idea what it could be. While mowing I spared it to see what it is.
The green leaves have a silvery tone to them, and the stem and underside of the leaves are quite silvery.