Horseradish (Armoracia rusticana, syn. Cochlearia armoracia) is a perennial plant roots with its powerfully pungent aroma and strong, hot, flavor. Powdered horseradish (the dried and ground root) can be reconstituted with water or sprinkled into foods that have enough liquid to reconstitute the spice. You can even sprinkle it like any other spice into dressings, sour cream, sauces, etc. Used In condiments such as seafood sauce, salads, as sauce for roast beef, and in Russian, and Middle Eastern cooking.