Coin-toss cholla. 

This is new growth on either staghorn or buckhorn cholla (Cylindropuntia versicolor or C. acanthocarpa, respectively). Both species occur locally, so I see one or the other frequently, but they look so similar they defy my small

diagnostic skills. Did I mention that they also readily hybridize where their ranges overlap? Of course they do, making it nearly impossible for tyros like me to identify them! 

At Pima Wash, South Mountain Preserve, in Phoenix, Arizona.

Coin-toss cholla. 

This is new growth on either staghorn or buckhorn cholla (Cylindropuntia versicolor or C. acanthocarpa, respectively). Both species occur locally, so I see one or the other frequently, but they look so similar they defy my small

diagnostic skills. Did I mention that they also readily hybridize where their ranges overlap? Of course they do, making it nearly impossible for tyros like me to identify them! 

At Pima Wash, South Mountain Preserve, in Phoenix, Arizona.

Honey bee (Apis mellifera) on desert wolfberry (Lycium andersonii). At Pima Wash in the South Mountain Preserve in Phoenix, Arizona. All of the wolfberry shrubs in the wash were covered in bees yesterday. At times the entire canyon seemed to be thrumming with the sound of thousands of honey bee wings. 

Honey bee (Apis mellifera) on desert wolfberry (Lycium andersonii). At Pima Wash in the South Mountain Preserve in Phoenix, Arizona. All of the wolfberry shrubs in the wash were covered in bees yesterday. At times the entire canyon seemed to be thrumming with the sound of thousands of honey bee wings.