Jane, Yes, this plant has leaves that are only 4 mm wide. Whatever it is, it is also hardy--surviving sub 15F temps and snow last year. I don't think Iris munzii would have lived through last winter in my yard. Iain suggested replanting it, so I may divide it in half, and take a very close look at the roots when I do so, to see what their structure is like. Thanks for your comments, Kathleen On Willapa Bay, Washington, as another sunny day ends.