The yellow iris is native to Europe, North Africa, British Isles and the Mediterranean region. It was introduced to the United States from Canada as an ornamental plant in the early 1900s, according to Montana War on Weeds.
The strong stalk extends 4 to 6 feet in height. There are usually four to 12 flowers, which extend 3 to 4 inches across, on each flower stalk. The flowering period is June through August.
Once established, the yellow iris grows best in shallow water, such as the edge of a stream, pond or marsh.
Under ideal growing conditions, yellow iris is a fast-growing weed that can easily dominate an area. To control the yellow iris, use a chopping machine to destroy the roots. At this time, there is no biocontrol for the yellow iris.
According to FloriData, over the centuries, the roots were dried and powdered for snuff, the flowers were used to make a yellow dye, and the rhizomes, the root base, made a powerful laxative.