This is a beautiful sport of 'Blue Mouse Ears'. The difference is that it has distinctively wavy leaves. Hosta 'Church Mouse' is a 2012 introduction. The 8" tall x 14" wide clumps are topped with short 8" tall flower scapes in midsummer.
Plant this Hosta in the front of a border, along paths or in a container. It forms a small mound of blue-green leaves with lighter green wavy margins with nice lavender flowers in July.