Variegated Sweet Flag (Acorus calamus 'Variegatus' a great accent plant for your pond. It grows upright 24" to 36" inches tall and prefers full or partial sun. Hardy in zones 4-11. It has beautiful white and green foliage that blends well with plants such as water for-get-me-nots, pickerel rush and cardinal flowers, to name a few. Its also a great plant to plant along edges of your pond to hid liners. It will tolerate up to 6 inches of water over its crown, though like most hardy bog plants it prefers moist soil.
This is also a great plant for someone who has a boggy area or swamp area in their yard.