Opuntia ficus-indica

The Indian fig opuntia, also called the prickly pear or nopal, is a large, branching cactus built from flat, fleshy, oblong pads that are really swollen stems, each coated in a waxy skin that sheds sun and water. It is the most widespread and commercially important of the long-domesticated cacti, grown across the dry and semiarid regions of the world mainly for its sweet fruits, called tunas, and for the young pads eaten as a vegetable. The plant also serves as fodder for livestock, as living hedges that slow erosion, and as the host on which cochineal insects are raised for red dye. Its wild origin is thought to lie in central Mexico, and it has spread so far with people that it is now regarded as an invasive weed in parts of northern Africa and Australia.