Oh, you must be right. That's *not* what I was thinking of...I was thinking of a ground cover I can't remember the name of that ends in repens (no, not dichondra - it had purple flowers very like this one). Well, so I suppose I don't want to plant it, then. It was growing among the forget me nots.

This species self seeds all over my allotment. You don't harvest it leaf by leaf. Just cut off a whole plant. It needs thorough rinsing because being a winter salad it gets a lot of mud splash and can be gritty if not carefully cleaned. The leaves are larger on the basal rosettes. Once they start to flower the leaves get smaller. But they're perfectly edible at any stage, including the flowers. And superior to lots of other wild greens imo. There are commercially available cultivars with larger leaves.

Thanks everybody for the feed back! I've got about 200 yards of a fence line that is on the edge of some woods that I'd like to slowly pull out the invasive exotics and replace with better plants. Background singers are important--if everything is a star nothing is a star. I have much use for a nice background singer that can take the mic for just a song or two then be unobtrusive for the rest of the season!

Using your genus tip I think it might be Hypericum punctatum (Spotted St. John's-wort). Also looked at H. mutilum and H. boreale but the leaves seemed too small.