This fruit is nicknamed the "dragon fruit" -- and I'm still not sure why. One of the Cambodian words for this fruit actually means "dragon scales." Well, the fruit actually does look like it has scales. Several other Southeast Asian names for this fruit indicates that it has some appearance of a dragon.
You would think that this fruit would be native of a Southeast Asian country like China, Japan, or Vietnam. But actually, this fruit is native of Latin American countries, particularly Central and South America. In Central America and some parts of South America, the fruit is called "pitaya roja" and "pitahaya" in Mexico.
It's believed that the French introduced the dragon fruit to Southeast Asian around the late 1800s. Currently, this fruit could be found ALL OVER Southeast Asia, including China, Taiwan, Vietnam, Malaysia, and Japan.
This fruit is grown on, of all things, a cactus! There are three varieties of this fruit throughout the world and they are distinguished by the color of their flesh: white, pink, and magenta (or a funky reddish color). The white variety is the least sweet, almost bland in taste. The magenta is the sweetest.
You most likely won't find this "exotic" fruit in your local grocery store, but probably in local health food stores or Asian markets. But if you happen to live in a hot climate and you happen to visit an Asian country where this fruit is grown, bring one back with you and grow it! There are plenty of seeds in this fruit to choose from!