Opuntia elatior (prickly pear)
Plant of the month: May
Arguably the largest cultivated specimen in the UK, this spectacular Opuntia is around 50 years old. Grown as a standard the prickly pear as its commonly known is usually seen in a more bushy habit. O. elatior is cultivated ornamentally but several Opuntias are cultivated for their edible fruits, O. ficus indica for example is often used to produce jellies, juices and to flavour tea. Native to Caribbean, Central America, Colombia and Venezuela. Opuntias have been widely distributed by humans as far as Australia, where it is noxious weed. O. striata was introduced to Australia in the early 19th century to establish a natural agricultural fence and to farm cochineal dye (produced by the cochineal scale insects that feed on Opuntias) but soon became invasive and rendered over 40,000 km² of agricultural land unusable. This is now controlled by the larvae of the Cactoblastus moth which is an early success of biological control. Farming of Opuntias was widespread in Mexico, Spain and the Canary Islands but was soon uneconomical with the introduction of less labour intensive synthetic dye production from Europe that it is now only done as a historical example of cochineal farming.