Our Mysterious New Yard

Last fall we moved into our current home and knew only of the sea of ferns in our backyard that would eventually have to go.  This spring we found that there are many more varieties of green things growing.  Many creeping, many spreading and all unknown to us.  Please help us if you can to identify the following.  We'd like to know what they are, if they spread, are they weeds...

(parentheses for updated id or possible id) 

1.  (lily)

2. (mystery lily ?md)

 
3. This I think turns into a bush...

4.

5.  This is a bit furry.

6. (columbine)

7.  May be the same as #3.  

 

8.  (ninebark ?pa)

10. The fern!

11.  Mossy something...

12.

13.  Flowering bush... (flowering almond/rose tree of China)

14. (Iris)

15. (viola ?md)

16. (choelus?)

17. (iris)

18. (snow on the mountain, bishop's weed)

19. (day lilies)