In dry areas of the world, leaf loss is associated with drought. Many trees and shrubs of the desert have ephemeral leaves that appear after rains. The drawback of this strategy is that the leaves can only produce food from the sun for a rather short period. Therefore, some of these plants have evolved to have green tissue on the branches and trunk. This green tissue can produce food for the plant when it is too dry to support leaves.
Mature specimens achieve a picturesque form.
The smooth bark is a pale green color. The branches bear small spines and have a loose, slightly weeping habit. Throughout the spring and summer, yellow, one-inch flowers are borne near the branch tips in clusters of two to ten. Although we tend to think of legumes as herbaceous plants, most members of the family grow in subtropical and tropical areas, and most of these are woody. Mexican palo verde occurs in dry areas of subtropical America.