Saguaro (Carnegiea gigantea) cacti begin to grow arms when they are 65 to 75 years old. While driving through Saguaro National Park in May, I spotted this blooming Saguaro in the pose of an inspirational singer with a woodpecker hole for its open singing "mouth" and two perfectly paired outstretched arms, each with a bouquet of white flowers.
I recently discovered a Saguaro in Tucson's Bear Canyon with a weird arm that drooped down along the ground like a spiny worm, allowing me to get a look at its shining white crown. Normally, the crowns of mature Saguaros are well above head level and not easy to see without a ladder.
Crested Saguaros are uncommon and have crowns with abnormal, cristate growth patterns. Unfortunately, this one below is turning brown and may be dying.
The gunshot-like hole in the center of its Medusa-like head was probably gouged out by a busy Gila Woodpecker. These desert birds are responsible for most of the holes in our Saguaro cacti. The woodpecker holes usually don't significantly harm the Saguaros unless the holes become too numerous or become infected with bacterial rot.
Many young Saguaros can be found growing in the temporary protective shade of shorter-lived "nurse trees" like paloverdes (Parkinsonia spp.), but some hardy Saguaros still manage to pop up in more improbable spots. I found this thin and a bit stunted Saguaro growing out of and up the side of a rock cliff.
I don't know how much longer this Saguaro can survive in this inhospitable location, but I'm surprised that it has survived here for as long as it has.