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 engelmannii (state) to the Tamaulipan matorral in Chihuahua (state), in Mexico. In the Sonoran Desert, terminal pads face predominantly east-west, so as to maximize the absorption of solar radiation during summer rains. Although found occasionally in the Mojave Desert, it tends to be replaced by "Opuntia basilaris", which does not need the summer rain. The overall form of "Opuntia engelmannii" is generally shrubby, with dense clumps up to high, usually with no apparent trunk. The pads are green (rarely blue-green), obovate to round, about 15–30 cm long and 12–20 cm wide. The glochids are yellow initially, then brown with age. Spines