Opuntia stricta, commonly known as the erect prickly pear or Australian pest pear, is a species of cactus native to the Americas but has become an invasive species in other parts of the world. The yellow flowers develop into red or purple edible fruits. Opuntia stricta thrives in arid and semi-arid environments and can form dense thickets that outcompete native vegetation, making it a significant ecological threat in areas where it is invasive.