Black Gamecock Iris blooms spring, blue-black color, looks black from a distance.  Blooms in early spring

Grows 24 to 36 inches tall

Full sun to part shade
Hardy zones 4 or higher

Louisiana Iris can be potted, or the rooted ends tucked into the rocks of a streambed or water fall.  Iris do very well soil-less read how. Your pond will stay much cleaner if you don't plant in dirt