Drive through the Maltese countryside in late summer and you cannot miss them. Rows of flat, paddle-shaped cacti line the rubble walls of fields, their spiny edges catching the light and their colourful fruits glowing orange, red, yellow or purple against the limestone landscape. Locally known as bajtar tax-xewk (prickly pears), these plants feel as Maltese as the ħajt tas-sejjieħ dry-stone walls they often grow along. Yet they are not native at all. How the Prickly Pear Arri