Blind Prickly Pear in Phoenix, Arizona

Odd name - The joints or pads have many evenly spaced, polka-dotted areoles bearing numerous rusty reddish-brown glochids (little barbed hairs or bristles). These glochids are loosely attached and are prone to dislodge and fly into the air when the plants are bumped or shaken. They get into animals' eyes and cause blindness. Hence the common name.