Opuntia demand is making cultivation of the insect an attractive opportunity in other regions, such as in Mexico, where cochineal production had declined again owing to the numerous natural enemies of the scale insect. Apart from cochineal, the red dye betanin can be extracted from some "Opuntia" plants themselves. Fluid ("cactus juice") extracted from "Opuntia" pads and stems, especially "O. ficus-indica", is one of the most commonly used additives in earthen plaster. The flesh ("mucilage") of the cactus has been found to purify water. A project at the University of South Florida is investigating its potential for low-cost, large-scale water purification.
Opuntia ovaries per carpel. Placentation is parietal, and the fruit is a berry with arillate seeds. Prickly pear species can vary greatly in habit; most are shrubs, but some, such as "Opuntia echios" of the Galápagos, are trees. "O. ficus-indica" thrives in regions with mild winters having a prolonged dry spell followed by hot summers with occasional rain and relatively low humidity. A mean annual rainfall of provides good growth rates. "O. ficus-indica" proliferates in various soils ranging from sub-acid to sub-alkaline, with clay content not exceeding 15-20% and the soil well-drained. The shallow root system enables the plant to grow