What type of plant do prickly pears grow on?

One adaptation of the prickly pear cactus [Opuntia spp] is its closeness to the ground. This proximity means that little moisture is loss on the way from the plant's water channeling spines, to the ground, and into the cactus' roots. Another adaptation is its defense mechanism, in the intimidating aspect and the painful impact of its barbed spines and bristles. Still another adaptation is the flexibility of its stem. The stem moves, processes and stores water, nutrient solutions, and energizing photosynthetic products. It gets larger with greater amounts of stored supplies, and smaller with lesser. Yet another is the spreading, shallow, fibrous nature of its roots. A cactus' roots are most effective and efficient in aggressively seeking out and capturing available soil moisture.