Dragon Fruit - Cactus fruit from Vietnam related to epiphyllum. Epiphyllum are called orchid cactus because of the large and impressive flowers. Some epiphyllum will bear fruit with cross pollination. Pitahaya is the Spanish name for the fruiting vines from tropical Central America. The vine usually has 3 ribs cross section. The plant was imported to Vietnam. The pitahaya will cross pollinate with the epiphyllum. The thornless dragon fruit is a bit like the kiwi and can weight up to 3 pounds.
While this fruit has become more popular in the U.S. it may be hard to find in many areas of the country. The fruit can be purchased online at Amazon.com: Fresh Dragon Fruit.