Opuntia other locations. Prickly pears (mostly "Opuntia stricta") were originally imported into Europe during the 1500s and Australia in the 18th century for gardens, and were later used as a natural agricultural fencing and in an attempt to establish a cochineal dye industry. They quickly became a widespread invasive weed, eventually converting of farming land into an impenetrable green jungle of prickly pear, in places high. Scores of farmers were driven off their land by what they called the "green hell"; their abandoned homes were crushed under the cactus growth, which advanced at a rate of per year. In 1919, the
Opuntia ficus-indica the wild origin of "O. ficus-indica" is likely to have been in Mexico due to the fact that its close genetic relatives are found in central Mexico. "Opuntia ficus-indica" is polyploid, hermaphrodite and autogamous. As "Opuntia" species grow in semi-arid environments, the main limiting factor in their environment is water. They have developed a number of adaptations to dry conditions, notably succulence. The perennial shrub "Opuntia ficus-indica" can grow up to 3-5m height, with thick, succulent and oblong to spatulate stems called cladodes. It has a water-repellent and sun-reflecting waxy epidermis. Cladodes that are 1–2 years old produce flowers, the