Cactus and their fruits are a large part of Mexican cuisine. The wide, flat cactus pads ("nopales") are used in many Mexican main dishes such as salads, eggs and as a filling for other dishes. The cactus fruit, sometimes called a "Prickly Pears" are very sweet and can be eaten raw, right off of the plant. Cactus fruit grows on the edges of the flat pads of the cactus, and are pear-shaped. They can range in color from green, to orange to red. The flavor of tunas changes sharply according to their ripeness level. If they are not quite ripe, they are slightly sweet with an acidic edge and, as they ripen, they get progressively sweeter until they remind one of candy. Zones 7-10.