Prickly Pear Fruit September is apparently the time when Opuntia (Prickly Pear) puts out its fruit. This is definitely apparent in many locations. Taken along the North Kaibab Trail.
This image is from the presentation "Desert Southwest - The Checklist Edition - Grand Canyon Rim-to-Rim Traverse, Day 2 - Clear Creek Campsite to Cottonwood Campsite".