There are two types of palo verde
Arizona hosts two native species, the Foothills Palo Verde and the Blue Palo Verde.
The Foothills Palo Verde (Cercidium microphyllum) can be found mostly on rocky slopes. They have a yellow-green trunk, tiny leaves and pods that constrict around the seeds.
The Blue Palo Verde (Cercidium floridum) are usually spotted next water sources, like washes, and have a blue-green trunk.