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 dulcis Opuntia dulcis Opuntia dulcis has been described as a variety of, and is confused with, "O. phaeacantha". However, "O. dulcis" is a larger plant with ascending branches, to 2 ft (exceptionally 4 ft). While it is a larger plant, immature specimens of O. dulcis may overlap in size with O. phaeacantha. "Opuntia dulcis" resembles "O. engelmannii" in some ways but does not become as erect or large as that species. Also, the spines of "O. dulcis" are finer than those of "O. engelmannii". "O. dulcis" is found across the deserts of the southwestern United States and northern Mexico. It is