Acorus calamus, commonly known as sweet flag, is a perennial wetland plant native to marshes and shallow waters in North America, Europe, and Asia. It features long, sword-like leaves and produces small, yellowish-green flowers on a spike. The plant thrives in moist, muddy soils and can grow up to 1.5 meters tall. Traditionally, Acorus calamus has been used in herbal medicine for its potential digestive and calming properties. The rhizome, or underground stem, is often dried and powdered for use in teas or tinctures. However, caution is advised, as some compounds in the plant can be toxic in large amounts.