Thorns are an evolutionary adaptation to protect a tree from predators or other animals that may cause it harm. Deer, for example, often seek the delicious leaves of bushes and trees, but they will avoid those that have sharp thorns. Several kinds of flowering trees have developed thorns as a defense mechanism. One example is the silk floss tree (Ceiba speciosa) which grows in U.S. Department of Agriculture plant hardiness zones 10a through 12b.
Of the more than 50 species of jacaranda trees, only one is grown in the U.S., and it has no thorns. The jacaranda tree grows in USDA zones 9b to 11, and while it tolerates many different types of soil, it does best in well-draining soil.
Jacaranda wood is quite friendly and attractive. With no thorns, it is gray and smooth when it is young. Once the tree matures, it develops grooves in the wood, and its branches twist and gnarl. When it rains, the wet branches darken, and their pattern stands out in a particularly lovely way.
Although they do not have thorns, jacaranda trees have notoriously weak wood that is dry and susceptible to breakage, especially in high winds. You can remove dead branches without fear of being pricked by thorns. Enjoy the special beauty of your jacaranda's gnarled trunk and glorious flowers.