Yellow flag is native to northern Africa and Eurasia that has been introduced in much of the world. It is considered invasive in eleven countries such as Australia, Japan, New Zealand, and the United States. It is considered a weed in much of North America. In the area of the Great Lakes, in particular, it has been cited as shrinking native habitats that house waterfowl, reducing the food supply for fish, and outcompeting other irises for pollinators. However, its vibrant flowers make it a popular garden ornamental. It is poisonous, so very few birds or mammals will eat it. In China, it is utilized to absorb cadmium and copper from contaminated waters. When necessary, yellow flag can be removed via the use of glyphosate and imazapyr herbicides.