Arrowroot is a bland-tasting root vegetable that is best known for being ground into powder for use in gluten-free dishes. The root, whose white flesh resembles that of a potato, grows to 3-6 inches long. The outside skin of the vegetable gives it a bad taste, so it must be removed before using. Arrowroot is also known as goo and Chinese potatoes. Available year-round, although quantities vary.