The large showy flowers of the blue flag iris brighten the sunny marsh areas in early summer. Early surveyors reported that this plant was very common in the extensive marsh areas of the Kankakee valley in pre-drainage times. Today, it is most frequently seen along ditch banks; however. Be careful using heavy equipment near this plant, it can easily be killed by soil compaction.
In Starke County, Indiana, where this individual was photographed, almost all marsh irises are a shade of blue.