This perennial has sword-like green leaves and long, straight flowering stems. Large purple-blue flowers have fine variegations of yellow, white, and black. Blue flag iris often grows in clump forming colonies.
Starts from seed bulbs, container.
Along shorelines, wet meadows, and marshes.
Root stock provides food for aquatic rodents, like muskrats.
A blue dye from the flowers can be used as a litmus substitute.
A medicinal poultice made from the roots was used by North American aboriginals.