The Palo verde trees are found mainly in the Sonoran desert, but are also found in deciduous areas. These perennial flowering trees are of medium size and large shrubs, and belong to the bean family. They, like almost all desert plants are excellent at tolerating drought conditions.
This tree’s name literally means “green wood” in Spanish, because of its greenish trunk. It is also called Parkinsonia (after the British botanist John Parkinson), Jerusalem thorn, and the jellybean tree.
The tree has many adaptations, such as its pendulous leaves, hairless stems and leaves, and large bark, which support its existence in the desert.
Its bark, which is studded with green thorns and waxy like a cactus, covers its large trunk, which plays a huge role in the process of photosynthesis. This green bark has chlorophyll, which is the main ingredient that supports photosynthesis and operates mainly when the leaves have shed during hot dry periods.
In other words, even when the leaves have shed (leaves are the main site of photosynthesis in plants), and sometimes even its branches and stems, the plant continues to produce nutrients because of the chlorophyll in its bark.
The tree has an extremely good root system. They dig deep into the ground in search of water as they live in very dry conditions. Compared to their rather small to medium size, their root system is huge, extending about 100 feet down.
The plant’s seedpods have a great mechanism too. The plant’s small yellow pods are full of seeds, which naturally attract many insects that play a vital role in the pollination of the plant throughout the desert.
Once the insects have eliminated the seeds after digestion, these germinate wherever they fall. These seeds are strong, and immediately start growing.
The Palo Verde tree is referred to as a drought deciduous plant. This means that during drought seasons it sheds its leaves to conserve nutrition which otherwise would have evaporated through the leaves (transpiration).
The Palo Verde has another important function, which goes beyond its looking after itself; it plays an important role in the desert ecosystem, being the primary nurse plant for saguaro cactus plants.
However, out of all this trees’ many adaptations, its green bark and its ability to continue the process of photosynthesis is its most amazing adaptation.