Acorus calamus, commonly known as Sweet Flag, is a perennial, wetland plant native to parts of Europe, Asia, and possibly North America, where it may have been introduced by early settlers. It typically grows 60 to 120 centimeters (2 to 4 feet) tall and resembles an iris, with long, sword-shaped leaves that emit a sweet, spicy fragrance when crushed. The plant produces a cylindrical, greenish-yellow flower spike (spadix) that emerges from the side of a leaf-like bract, though flowering is infrequent in some regions. Sweet Flag grows in marshes, along streambanks, and in other wet soils. It has a long history of medicinal and aromatic use, particularly the rhizomes, which were traditionally used for digestive and calming remedies.