Photograph of 18 cacti fruits growing on the flat-jointed paddles of the prickly pear, ca.1920. Dangling pear-like fruit hangs from a single flap of cactus, set against a neutral background.; "Prickly Pear Cactus have been a staple food of Native Americans for many centuries. Their large, colorful blossoms appear in yellow, pink, red or purple and grow from the tip of cactus nodules, which later ripen into delicious red fruit. Many varieties of prickly pear cactus grow wild throughout the deserts of the Southwest, but many are not native. Some species of prickly pear cactus were introduced into North America from tropical America a number of centuries ago. The fruit of these cultivated prickly pear cactus is a common delicacy in Mexico and is sold in markets as "tuna." While all prickly pear cacti are of the genus Opuntia, the non-native Opuntia megacantha is one of the tastiest and most popular. Some native species, especially those with dark purple fruit, are not as flavorful." -- unknown author.