A 'pitaya' is the fruit of several different cactus species indigenous to the Americas. These fruits are commonly known in English as "dragon fruit", a name used since around 1993, apparently resulting from the leather-like skin and prominent scaly spikes on the fruit exterior.

The names 'pitahaya' and 'pitaya' derive from Mexico, and 'pitaya roja' in Central America and northern South America, possibly relating to 'pitahaya' for names of tall cacti species with flowering fruit. The fruit may also be known as a strawberry pear.

The dragon fruit is cultivated in Southeast Asia, Florida, the Caribbean, Australia, and throughout tropical and subtropical regions of the world.

The fruit's texture is sometimes likened to that of the kiwifruit because of its black, crunchy seeds. The seed oil contains the fatty acids, linoleic acid and linolenic acid.

Dragon fruit is used to flavor and color juices and alcoholic beverages, such as "Dragon's Blood Punch" and the "Dragotini". The flowers can be eaten or steeped as tea.

The red and purple colors of 'Hylocereus' fruits are due to betacyanins, a family of pigments that includes betanin, the same substance that gives beets, Swiss chard, and amaranth their red color.

Dragon fruit contains the antioxidants vitamin C, beta-carotene, lycopene and betalain. Studies have linked diets high in antioxidants to a reduced risk of chronic disease.

More Info: en.wikipedia.org