Prickly Pear Cactus

Opuntia is a genus in the cactus family, Cactaceae.

The most common culinary species is the Indian fig opuntia (O. ficus-indica). Most culinary uses of the term "prickly pear" refer to this species. Prickly pears are also known as tuna (fruit), sabra, nopal (paddle, plural nopales) from the Nahuatl word nōpalli for the pads, or nostle, from the Nahuatl word nōchtli for the fruit; or paddle cactus.

The genus is named for the Ancient Greek city of Opus, where, according to Theophrastus, an edible plant grew which could be propagated by rooting its leaves.

Like all true cactus species, prickly pears are native only to the Americas, but they have been introduced to other parts of the globe. Prickly pear species are found in abundance in Mexico, especially in the central and western regions, and in the Caribbean islands (West Indies). In the United States, prickly pears are native to many areas of the arid Western United States, including the lower elevations of the Rocky Mountains, where species such as Opuntia phaeacantha and Opuntia polyacantha become dominant, and to the desert Southwest, where several types are endemic. Prickly pear cactus is also native to coastal beach scrub environments and low open areas of the East Coast from Florida to Connecticut/Long Island (Opuntia humifusa).

Prickly pears typically grow with flat, rounded cladodes (also called platyclades) armed with two kinds of spines; large, smooth, fixed spines and small, hairlike prickles called glochids, that easily penetrate skin and detach from the plant. Many types of prickly pears grow into dense, tangled structures.

Below, Prickly Pear fruit for sale at a market, Zacatecas, Mexico

The fruit of prickly pears, commonly called cactus fruit, cactus fig, Indian fig, nopales or tuna in Spanish, is edible, although it must be peeled carefully to remove the small spines on the outer skin before consumption. If the outer layer is not properly removed, glochids can be ingested, causing discomfort of the throat, lips, and tongue, as the small spines are easily lodged in the skin. Native Americans, like the Tequesta, would roll the fruit around in a suitable medium (e.g. grit) to "sand" off the glochids. Alternatively, rotating the fruit in the flame of a campfire or torch has been used to remove the glochids. Today, parthenocarpic (seedless) cultivars are also available.

Dactylopius coccus is a scale insect from which cochineal dye is derived. D. coccus itself is native to tropical and subtropical South America and Mexico. This insect, a primarily sessile parasite, lives on cacti from the genus Opuntia, feeding on moisture and nutrients in the cactus sap. The insect produces carminic acid, which deters predation by other insects. The carminic acid can be extracted from the insect's body and eggs to make the red dye.

Cochineal is used primarily as a red food colouring and for cosmetics. The cochineal dye was used by the Aztec and Maya peoples of Central and North America. Produced almost exclusively in Oaxaca, Mexico, by indigenous producers, cochineal became Mexico's second-most valued export after silver. The dyestuff was consumed throughout Europe, and was so highly valued, its price was regularly quoted on the London and Amsterdam Commodity Exchanges.

Right image, traditional "Zapotec nest" farming of the cochineal scale insect on O. ficus-indica, Oaxaca

Information culled from Wikipedia. So I can only guess as to the correctness of the information.