The Joshua Tree
The Joshua Tree, the largest of the yuccas, grows only in the Mojave Desert. Natural stands of this picturesque, spike-leafed evergreen grow nowhere else in the world. Its height varies from 15-40 feet with a diameter of 1-3 feet. Joshua trees (and most other yuccas) rely on the female Pronuba Moth (Tegeticula) for pollination. No other creature visiting the blooms transfers the pollen from one flower to another.

The Saguaro
Saguaros often begin life in the shelter of a "nurse" tree or shrub which provides a shaded, moister habitat. The largest plants are estimated to be 200 years old and can reach heights of 15 to 50 feet.