Other Names: Iris versicolor, Iris, Iris caroliniana, Iris Versicolore, Iris virginica, Clajeux, Lirio Azul, Lis Bleu, Sweet Flag, Water Flag.<br>Blue flag is a perennial herb native to North America, and cultivated elsewhere in the world. People use the underground stem (rhizome) of blue flag to make medicine.<br>See also : [[Orris]] (Iris florentina)
==Special Precautions of Blue Flag==
* The rhizomes of Blue Flag can be dangerously toxic if taken internally in large doses, causing nausea, vomiting, and headaches.