FIELD GUIDE
NO.
007
Foothill Palo Verde
Parkinsonia microphylla
CLASS: Magnoliopsida
FAMILY: Fabaceae ORDER: Fabales
GENUS: Parkinsonia
AT A GLANCE
SIZE
10-25 ft (3-7m)
STATUS
Native – Not federally protected
HABITAT
Bajadas, rocky foothills, plains and desert slopes
RANGE
Sonoran Desert of Arizona, southeastern California and northwestern Mexico.
DIET
Sunlight – Water – Carbon dioxide – Soil nutrients
TRAITS
Drought Tolerant – Nurse Tree – Photosynthetic bark
LIFE SPAN
100 – 300 years
WHAT TO NOTICE
Look first at the green.
The trunk and branches of a Foothill Palo Verde contain chlorophyll, allowing the tree to photosynthesize through its bark. Its tiny leaves can be shed when water becomes scarce, while the green limbs continue to gather energy from the sunlight.
The canopy is open and spreading, made from an intricate architecture of yellow-green branches. Mature trees may develop multiple substantial trunks and broad crowns.
Its flowers are pollinated primarily by insects, especially bees. The entire tree may buzz with swarms of bees. Its seeds become food for desert animals. Its canopy moderates the environment below, reducing intense solar radiation and buffering temperature extremes.
HOW IT LIVES:
The Palo Verde is built around scarcity.
Tiny leaves appear when moisture is available and can disappear during drought, leaving a green carpet beneath the tree.
In a landscape defined by exposure, the Palo Verde Trees create shelter.
THE INTERESTING PART
The Palo Verde plays an important ecological role in the desert by acting as a nurse tree to many young plants and animals of the desert.
Beneath its canopy, the desert is slightly different from the exposed ground surrounding it. There is less direct sunlight and less extreme heat, creating conditions in which other plants can become established.
WHERE I FOUND IT:
Tom Thumb’s Trailhead, Scottsdale Arizona January
On a January evening, in the fading light of the Sonoran Desert, my husband and I paid a visit to the trailhead at Tom’s Thumb to watch the sunset and listen for coyotes.
Our favorite discovery was this standing guardian of the desert.
Her reaching green limbs filtered a warm and moody light that sparkled on the space below. Her presence and the atmosphere were irresistible.
Buzzing and alive with bees, this particular tree has likely been protecting desert creatures for many decades. At approximately twenty feet tall, her canopy appeared nearly thirty feet wide, and she had grown a substantial double trunk.
She is not the only Palo Verde in the Sonoran Desert.
But she may be the most beautiful.
WORDS TO KNOW:
Palo Verde – Spanish for “green stick,” referring to the tree’s green, photosynthetic bark.
Bajada – A broad, gently sloping apron of sediment that forms along the base of desert mountains.
Nurse Tree – A plant whose canopy creates a protected microhabitat that helps other plants become established.
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