The caper bush is a perennial winter-deciduous species that bears rounded, fleshy leaves and large white to pinkish-white flowers with elongated stamens. They are a relative of the cabbage family. Capers refer to the bud of this plant, pickled for culinary usage. When the fruit has matured, they are instead called caper berries. When ready to pick, the buds turn olive green and measure about 0.3 – 0.5 centimeters in diameter. Small capers are considered more premium and the buds are categorized by size for sale. During its pickling process, the capers develop an intense flavour through the release of mustard oil, spicy, sour, astringent and pungent.