Popular since ancient times, horseradish is a perennial plant cultivated for its large root. Although the whole unbroken root itself has hardly any aroma, when cut or grated, watch out! This hot, spicy and highly flavored vegetable is usually crushed or grated into a sauce that accompanies beef, chicken and seafood. Horseradish has a long history as an aphrodisiac, a medicine for rheumatism and headaches, and still serves as one of the five bitter herbs of the Jewish Passover.