This iris is also known as Roof Iris or Wall Iris. This species iris is from china where it was in fact grown on thatched roofs and walls. It is about a foot tall and is blue/purple with a white crest. It is beardless and the foliage looks similar to a semi dwarf bearded but tends to lie flatter rather than standing upright. This iris is reported by some sources to be hardy in zone 4 and some report it as zone 5 but I think more important is the drainage. It does require water, but it must not stand in water at all. Very well drained soil and a sunny protected position will keep it happy. The powdered roots are used as a white face powder by women in Japan. It is also thought to ward off evil spirits.