There are over 150 species (up to 300 according to some sources) of prickly pear, native to the Americas, primarily in the arid regions, although it has now found its way around the World. Most are cold tolerant. Opuntia have flat jointed leaves.
Books to Consider
Name Derivation: Named after Opus (Greece), an area where other cactus-like plants were grown
Common Name: Prickly Pear
Opuntia is in the family Cactaceae.