Sweet flag is a tall reedlike plant of the arum family. It grows along brooks and in marshy places in almost all parts of the Northern Hemisphere. Its leaves are flat and 2 to 6 feet (61 to 180 centimeters) long. They are shaped like a two-edged sword. The stems are almost like the leaves but are stiffer and bear spiky clusters of small green blossoms near the top. The leaves and stems rise directly from a thick, fleshy underground rhizome (horizontal stem). The rhizome has been used medicinally since ancient times. Today, it is also used in the manufacture of perfume and other toilet preparations. In Europe, the rhizome is valued as a food.
