Acorus calamus is commonly called sweet flag . It is a light green colored reed-like plant that is found throughout the state. It is hardy in zones 4-9, and one of its more intriguing qualities is the spicy fragrance released when the foliage is crushed or broken. Variegatus' is a cultivar with variegated green and white foliage. There are a variety of sedges that can also be planted for wetlands to provide height and texture.
Rushes are also nice natural looking plants for wet areas.
Juncus acuminatus is an example, it is otherwise known as the tapertip rush and has a showy red to pink flowering seed head. Plants are 3-4 feet tall and are hardy in Iowa. Wild rice is another alternative as well. Zizania aquatica is a tall grassy plant, up to 10 feet tall, with long, white plumes of seeds. Though rare, wild rice is native to northeast Iowa.