I learned from Wikipedia that dragon fruit is also known as pitahaya and is the fruit of cacti of the genus Hylocereus native to Mexico, Central America, and South America. Dragon fruit is also cultivated in East Asian and Southeast Asian countries as well as Bangladesh, Okinawa, Hawaii, Israel, northern Australia, southern China, and in Cyprus.
Curious about the claim by the two shoppers that dragon fruit is a nutritional powerhouse, I tried looking up the nutritional content at the USDA National Nutrient Database website, and there’s no entry under either dragon fruit or pitahaya. I went to the SELFNutritionData website to no avail as well. So unfortunately I was unable to confirm the nutritional claim of my fellow shoppers, and hopefully they were right. Overall it was an interesting experience!