Iris Tectorum

A 15" tall species of the crested iris group featuring large, 6" across, beardless, bright lilac-purple flowers with falls which are crested white. Foliage is arranged in fans of narrow, lance-shaped, ribbed, glossy, upright leaves that can become somewhat floppy. Can spread rapidly in the garden. Commonly called roof iris because it has in the past been grown on thatched roofs in both Japan and China.