The prickly pear (opuntia ficus indica) is a Mexican plant brought to Europe by 16th century voyagers. It endures drought, needs very little soil to take root in and flourishes in the Mediterranean. It can reach a height of 4 to 5 metres. Its branches being broad like tennis rackets, full of small prickles it becomes an impenetrable hedge and has on occasion been used as a barricade. Grown as a fence around castles, today it grows on most hills where castles stand. The cactus being juicy on the inside is used today as a firewall.

* Until 1950 the prickly pear fruit was a very common fruit until people stopped eating it. It has recently been found to be full of vitamins and minerals.