The grass-like perennials that comprise the genus Acorus of the family Acoraceae are commonly known as sweet flag. The plants inhabit moist soils and shallow waters, such as those found in marshes and along the edges of ponds and lakes. Sweet flag leaves are aromatic when bruised and resemble in appearance the long, narrow leaves of irises, which are also sometimes called flags. When sweet flag blossoms, a rare occurrence, the flowers take the form of brownish-green cylindrical spikes, and the fruit of the plant is an externally dry berry containing a small number of seeds.