Louisiana Iris - $12
As its name suggests, this is a water iris from the swamps of Louisiana. It is found growing in shallow water or boggy and marginal areas. This iris is evergreen and tolerates light frosts. However, I have been able to grow them in a sheltered position successfully for years in an area that gets heavy frost. Spectacular flowers in Spring.
I find it easier to grow this iris in a plastic pot and place it in the pond.