I was asked why I call the fruit on Prickly Pear cacti "tuna's" and after looking in my reference books that is what they call them.
The word 'tuna' is Spanish for the fruit of a plant. That's why it's used to describe the fruit of the prickly pear cactus [Opuntia spp]. I also looked online and found this article:
In late summer in Mexico, prickly pear cactus fruits, or tunas, are everywhere—a refreshing snack eaten out of hand and a popular ingredient in candies, drinks, jams, and more. In Oaxaca, they spoon a dollop of pureed tunas on top of horchata, the milky rice-almond drink, but you can use it just about anywhere you'd use an apple—in salads, for example, or even in tarts. The cactus grows wild all over Mexico; it's also cultivated on plantations. Cactus pads, or nopales, are eaten year-round, but it's only in summer that the fruits reach maturity. Varieties number in the hundreds, with flavor profiles ranging from creamy-sweet to brisk and tart. The dark nubs on the skin contain sharp spines, but these are easily removed by slicing off the ends of the fruit, making lengthwise incisions, and peeling back the rind to reveal the luscious flesh.
