Saguaro National Park

   The traditional symbol of the desert Southwest is the saguaro (sa-war-oh) cactus universally recognized by its distinctive shape even by those who do not know its name. Though it represents all American desert, it grows only in the Sonoran. (The others are Chihuahuan, Mojave, and Great Basin.) The saguaro can tolerate only a short period of freezing weather and above 4,000 feet it grows only on south-facing slopes. Saguaros that have been touched by a freeze can often be recognized by drooping arms that may bend and grow erect again as they recover.
   The national park that celebrates this noble cactus has two districts located just east and west of Tucson, AZ. There are 25 species of cacti in the park, the most common of which are the fishhook barrel, the prickly pear, pinkflower hedgehog, and three kinds of cholla (choy-a): staghorn, teddy bear, and chainfruit. The thorny-stemmed ocotillo is common but it is technically a shrub, not a cactus.
   When we are at Tucson, we stay at Gilbert Ray Campground in Tuscon Mountain Park just over Gates Pass from the city. Because of the intervening ridge, you would never know that you are so close to a large population center. Normally, we would prefer to camp in the national park but there is no campground at Saguaro. Well, that is not totally accurate. There are several wilderness, back-county sites that can be reached only by backpackers. And there is no water or any other amenity. Basically just bare spots in the desert. Even so, you need to have a permit to pitch your tent in the bare spots.
   You can see just about anything you want to see by taking loop roads through the park along which there are hiking trails. The roads are dirt and gravel and bumpy and rutted. Nothing wrong with that as long as you know what you are getting into. And don't go when rain is expected or has recently occurred. Flash floods in the desert are nothing to kid about.

It can take a saguaro 70 years or so to grow its first arm. If you see one with several large arms you know it must be quite old. Hard to tell the age of saguaro, though. No tree rings to count. Scientists measure relative age by looking at old photos and noting changes over the years. Best guess is they live for more than 200 years. Maybe.

Easy to see how the fishhook barrel cactus got its name.

The ocotillo gets flame-red blossoms at the end of long, thorny stems very quickly after a rain. It may bloom several times in a year.

After a rain, the ocotillo leafs out and blooms faster than you would think possible.

After blossoming, ocotillo leaves turn red and gold then drop off just like the leaves of deciduous trees in the North.

Accordion pleats allow the cactus to expand and hold more water after a rain.

Ancient Indians left petroglyphs some of which may be up to 4,000 years old. (But destroyed in 4 seconds by vandals.) Petroglyphs, incised into the rock surface, are not to be confused with pictographs that are painted on.

Across the road from the national park is the Sonoran Desert Museum. In addition to the museum buildings that house things like geological displays there is a huge open air zoo where you can easily see animals that may be somewhat more elusive in the wild.

  

A barrel cactus may be thought of as a desert compass because it tends to lean to the south. Sort of the way that moss is said to grow on the north side of a tree.

The curved bill thrasher, a cousin of the mockingbird, sings the songs of several other desert birds. 

Crested or cristated cacti have deformations that are believed to be genetic.