Annual or biennial plant (Raphanus sativus) of the mustard family, probably of Oriental origin, grown for its large, succulent root. Low in calories and high in bulk, radishes have a sharp taste and are usually eaten raw. The shape of the edible portion of the root varies greatly, as does the colour (from white through pink to red, purple, and black). Radishes may weigh only a few ounces (U.S. and European varieties) or, in the case of the Japanese daikon, more than 2 lbs (1 kg).