Acorus calamus, commonly known as sweet flag, is a perennial herbaceous plant native to wetlands in Europe, Asia, and North America. It is a member of the Acoraceae family and is often found growing along the edges of ponds, streams, and marshes.
Sweet flag has long, sword-shaped leaves that are often mistaken for grass or iris leaves. The leaves are aromatic when crushed and have a sweet, spicy scent. The plant produces small, inconspicuous flowers on a spadix surrounded by a green or yellowish spathe, similar to those of a peace lily or jack-in-the-pulpit.
In traditional medicine systems such as Ayurveda and traditional Chinese medicine, various parts of the sweet flag plant, including the rhizomes (underground stems), have been used for their medicinal properties. They are believed to have digestive, carminative, and stimulant properties. However, it's essential to note that the plant contains several potentially toxic compounds, including β-asarone, which has been linked to carcinogenic effects in animal studies. Therefore, caution should be exercised when using sweet flag medicinally.
In addition to its medicinal uses, sweet flag is also cultivated ornamentally in water gardens and naturalistic landscapes for its attractive foliage and pleasant fragrance. It can spread vigorously in favorable conditions, forming dense colonies along the edges of ponds and lakes. Hardy in zones 4-10.