Plant Fact Sheet

Fabaceae
Palo Verde
Parkinsonia florida
(Cercidium floridum)

Cercidium floridum, a member of the Desert Scrub Community, is native to the Sonoran Desert. It commonly occurs in washes and floodplains and sometimes on rocky slopes that are no higher than 4,000 feet. This relatively small tree can obtain a height of approximately 32 feet and trunk diameter of 1.5 – 2 feet. Cercidium floridum has a deep root system which allows it to tap into the ground water and survive periods of extended drought. These deep roots also allow this desert tree to withstand severe flash floods which often occur in desert washes.
Cercidium floridum has been aptly named Palo Verde which means ‘green stick’ in Spanish. The green stems and bark of Palo Verde make it easy to identify but more importantly allow it to persist in the desert environment. Palo Verde trees are drought deciduous and thus shed their leaves during extended dry spells. When no leaves are present the plant relies on its green stems and branches to carry on the essential energy-producing process of photosynthesis. The leaves of Palo Verde are so small that even during the short periods (mid July to late November) when they are present they still need assistance with photosynthesis. It has been documented that younger stems have a higher photosynthetic rate than older stems. Mature Palo Verde trees are often marked by their distinct grey bases.

Palo Verde begins flowering in late March and continues to flower until May. During this time the tree becomes covered in small yellow flowers creating a stunning display of color. When standing under a Palo Verde during its bloom time one cannot ignore the gratifying sound of both native and imported honeybees working diligently to pollinate the tree. The seeds pods of Palo Verde typically appear about one month after flowering.

The Cahuilla Indians were known to harvest the seeds during the months of July to August. The seeds were dried and ground in mortars to produce a flour which could be used to make a mush or to make cakes. Palo Verde seeds were also a known food source for the Pima and Papago Indians of Arizona.

Cercidium floridum is also a great landscaping tree for the home garden. These native trees will provide the gardener with light shade, a spring show of yellow flowers, and an opportunity to observe our local wildlife up close. Palo Verde trees are highly drought tolerant but supplemental water will increase the growth rate of the tree and ensure a prolific bloom. Established trees will respond to a monthly deep soaking in the winter and a bi-monthly soaking in the summer. Un-established trees will need additional water during both the cool and warm season. If left unattended Palo Verde trees will grow into a shrubby tree with branches growing low to the ground. It is possible however to lift Palo Verde trees in order to create a canopy without completely compromising the natural feel of the tree. The Living Desert offers excellent examples of Palo Verde trees that have been pruned to achieve this look.