Opuntia macrocentra populations of "Opuntia macrocentra" are found in Arizona, New Mexico, Southwestern Texas, and Northwestern Mexico. This cacti is a slow growing perennial that inhabits a wide range of soil substrates and habitat types. It can be found below the elevation of 5000 ft in areas of sandy desert flats, rocky hills, or valley grasslands. "Opuntia macrocentra" is an upright spreading shrub, usually growing from tall. Individuals occasionally reach in height. The stem is blue-gray, blue-green, or purplish in color. The purple pad color is the most intense at the edges of the pad or around the areoles. The purple color
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