Maybe it is Camellia japonica ssp. rustica, AKA Camellia japonica var. decumbens, (decumbens meaning prostrate.) More pics.

Your reason is the reason I thought it was not Lychnis chalcedonica. Since I have Maltese Cross in another section of the garden I took flowers and leaves from the mystery plant and examined them next to the known plant. They are virtually the same. The color, texture, shape of the leaves and petals all match. The difference was the delicate plant versus the very sturdy plant that grows elsewhere. I decided that since the "volunteer" was new it was just delicate and not fully developed. It came up in what's supposed to be my new strawberry patch. Many volunteers showed up there since the strawberries have been slow to take hold. Thanks for your input. I really appreciate it.

Nancy, I beg your pardon - I seemed to have skipped over the text of your message. As Christopher points out, a 20 y/o isn't a bairn. But it does look a young A.m. that hasn't had enough sun, and, as you've noted, a less-than-optimum mix. I don't see how that plant could have seen 20 summers, but there you have it. And this is how you will have it. This one's originally from Miles2go, the last plant of the lot, something Miles had apparently looked forward to getting rid of, and it's grown well, once I stopped rotting its roots. I'm torn btw repotting now versus in the late spring 2011. I'd have that one ready for outside growing as soon as your weather allows for it - a very loose mix and regular watering will make this plant happy in the summer.

I was kind of suspicious of that, Gldno, since not only are there clumps of rose campion in her garden but also along a lonnnng section of fence. I knew surely she didn't BUY all those plants, lol.