The spicy root of the horseradish plant is a widely used condiment. Native to southeast Europe, it is currently widely cultivated in Germany. In Japan, it is called wasabi, and forms a ubiquitous part of sushi cuisine.

Horseradish root also has a long history of medicinal use. Taken internally, it was thought to be effective for bladder infections as well as other bladder and kidney problems. (Horseradish oil once formed a part of a drug licensed in the US for treatment of bladder infection; however, contrary to statements made on some websites, this drug is no longer in use.) Horseradish was also taken internally as a treatment for respiratory infections and for joint pain. It was also applied externally in the form of a poultice to wounds, painful joints, and strained muscles.