Iris were brought to North America from Europe as an ornamental plant.  Still a favorite amongst gardeners and flower lovers, you can often buy cut iris flowers from garden shops in the spring.  There are many colors to choose from within the 100+ varieties, but this rich purple seems to be the most popular.

Generally, iris do well in a moist or wet environment.  This tall iris is a garden resident, but I have also seen wild yellow iris that grow by lakes.  (Specifically the lakes at Morton Arboretum in Lisle, Illinois.)  Iris are often spoke of as being poisonous, as only a very skilled herbalist can safely administer this plant.