Dragon fruit (English: pitaya) is a fruit of several types of cactus from the genera Hylocereus and Selenicereus. This fruit comes from Mexico, Central America and South America but is now also cultivated in Asian countries such as Taiwan, Vietnam, Philippines, Indonesia and Malaysia. This fruit can also be found in Okinawa, Israel, northern Australia and southern China. Hylocereus only blooms at night.

In 1870 the French were brought from Guyana to Vietnam as ornamental plants. By the Vietnamese and Chinese people the fruit was considered to bring blessings. Therefore, this fruit is always placed between two green dragon statues on the altar table. The red color of the fruit is striking between the colors of the green dragons. It is from this habit that the fruit among the Vietnamese people who are heavily influenced by Chinese culture is known as thang loy (dragon fruit). The term Thang loy is then translated in Europe and other countries that speak English as dragon fruit.