Engelmann's Prickly Pear (Opuntia engelmannii)

I think these are Engelmann's prickly pear based on the descriptions I've seen. These were photographed in the Sonoran Desert near Tucson. Prickly pear are in the same group of cacti as cholla (genus Opuntia) but prickly pear have the well known flat pads instead of the roundish branches of cholla.
The name "prickly pear" comes from the fruit. Pear-shaped fruit in various colors from yellow to red to dark purple are grown at the tips of the pads on various varieties of prickly pear. The most well known is the Indian fig cactus (Opuntia ficus-indica) that originated in central Mexico. It has been cultivated all over the world for hundreds of hears to produce the prickly pear we can find in markets.
We read on the nature trail in Catalina State Park that the prickly pear in the Sonora Desert turn their paddles to avoid direct sunlight to the flat of the pad.
Native Americans of the Southwest cooked both the pads and the fruit. The pads, called nopalitos, have been shown to lower cholesterol and stabilize blood sugar levels. The fruit appear to have similar properties. Native Americans have used tongs to gather the fruit which are rubbed down with straw to remove the little spines called glochids. The fruit are then peeled and eaten or dried and stored.