Iris versicolor. Blue Flag, or Flower de luce.
Botanical name:
Classic texts: Bigelow 1817-1821.
Classic texts: Bigelow 1817-1821.
Iris prismatica Pursh. ex Ker Gawl.
Engl.: slender blue iris.
Bot. syn.: Iris carolina Radius, Iris gracilis Bigel.
Henriette's herbal is one of the oldest and largest herbal medicine sites on the net. It's been online since 1995, and is run by Henriette Kress, a herbalist in Helsinki, Finland.