Retirado de: http://en.wikipedia.org/wiki/Opuntiaficus-indica
Opuntia ficus-indica is a species of cactus that has long been a domesticated crop plant important in agricultural economies throughout arid and semiarid parts of the world. It is thought to possibly be native to Mexico. Some of the common English names for the plant and its fruit are Indian fig opuntia, barbary fig, cactus pear and prickly pear, although this last name has also been applied to other less common Opuntia species.
Fig opuntia is grown primarily as a fruit crop, but also for the vegetable nopales and other uses. Most culinary references to the "prickly pear" are referring to this species. The name "tuna" is also used for the fruit of this cactus, and for Opuntia in general; according to Alexander von Humboldt, it was a word of Hispaniola native origin taken into the Spanish language around 1500 CE. Opuntia ficus-indica (Indian fig) in Secunderabad, India.
Cacti are good crops for dry areas because they efficiently convert water into biomass. O. ficus-indica, as the most widespread of the long-domesticated cactuses, is as economically important as corn and tequila agave in Mexico today. Because Opuntia species hybridize easily (much like oaks), the wild origin of O. ficus-indica is likely to have been Mexico due to the fact that its close genetic relatives are found in central Mexico.