The fruits of the barrel cactus are delicious—the texture is roughly comparable to a bell pepper, the flavour similar to that of a citrus fruit, and the tiny seeds are crunchy, very like poppy seeds.
I remember several books of my youth advising that, if one were lost in the desert, barrel cactus could be used as a source of water—but apparently some species are poisonous. Just as well we carried water with us, and didn't get lost.
We have prickly pear in Nebraska, but they tend to be small and obscure—nothing like the specimens we saw in Sonora country.
You don't want to get too cuddly with cactus in general, but cholla is in its own league. One species is known as jumping cholla for the ease with which its thorns dislodge. From the plant, that is. They have backwards-pointing barbs, like microscopic fishhooks, so to get them out of your flesh you'll need pliers.
The flowers, though, are quite lovely, even past their prime.
[Group shot, L-R: prickly pear, barrel cactus, cholla. There is a "spear" saguaro in the background.]
The prototypical cactus of western deserts in many peoples' minds, saguaro are actually quite unique (one species of saguaro as opposed to dozens of species of cholla, a couple hundred of prickly pear, and for barrel cactuses how many depends on which genera you count as fitting the description) and are endemic to a single desert, the Sonoran.
[As the song says, "Ain't No Saguaro In Texas", so this logo is flat-out wrong.]
Not technically a cactus, ocotillo is close enough for me to include it here. If I were a hummingbird, I would love me some ocotillo.
To close, a few random photos.