I also forgot to mention this is a very damp area in the winter...............

If you can find and transplant some pieces of moss, it will look wonderful. It does take a while to get established, but you can help it along with the buttermilk and water treatment (more about that in the moss forum). Mosses love shady moist clay and are usually a lovely spring green. Also, Lysimachia nummularia aurea would succeed but does tend to take over. Also check out the Selaginellas (S. uncinata is the beautiful peacock moss, and S. kraussiana aurea is a beautiful lime colored moss--think I spelled them correctly).

I think laur's got it- moss would be your best bet, transplanted from a similar ecosphere (damp, shady) it's one of the few things that's fine with boggy feet in the winter.

you could try lobelia, which may self-seed or even be semi-hardy in your neck of the woods (by the way, I'm jealous- BC's GEORGEOUS even without landscaping ;) it's maybe 4" tall tops, and makes little violet flowers.