When you are at a State or National Park trying to locate flowers to photograph and cannot find any, go to their visitor center. They usually always have a watered, well cared for garden/nature trail displaying all the local flora that are to be found in the area. Just don't tell anyone this is what you had to resort to.
A flowering Yucca. Notice how the bees like it.
Taken with a polarizing filter.
Cholla backlit by the sun.
Another Barrel Cactus with blossoms to come, blossoms all done and one in it's glory.
Beavertail cactus flower not quite fully opened. This is one cactus you do not want to touch. The spines are like fine little hairs, extremely difficult to see and remove and they hurt for days!
Yes, these were taken at the visitor center at Anza Borrego State Park.