Never mind. It's a dwarf iris.

I was given this iris.
All I know is it's small and white. The rhizomes don't look like bearded iris. Is it a cristata? The leaves are longer than what I remember, about 8 inches. I need to know where to plant it!

Those somewhat ribbed leaves don't look like a bearded iris, either.

I have Iris japonica, and it grows similarly.. Cristata and a couple of other species are nearly indistinguishable to me from japonica in pictures, but have the same growth habit as yours...
Daisy, I think the pleating is cultural, or weather related.. it happens sometimes with bearded Iris.. the fan on the left in her picture looks unaffected..

I get horizontal accordian pleating on my LA irises, which I've been told is cultural, but not verticle ribbing. But if all those roots are conneced in the above shot, then yes, it could be cultural. I had thought at first glance that the one on the left was separate, and a TB.