What tree or shrub resembling a crepe myrtle has thorns or spine at the end of the branches?

The tree you’re describing is likely the Crape Myrtle (Lagerstroemia), specifically some varieties that can develop thorns or spines. While standard Crape Myrtles are typically thornless, certain hybrids or related species may exhibit this trait. Another possibility is the Barbados Cherry (Malpighia emarginata), which can resemble a Crape Myrtle and has thorny branches. Both plants are known for their vibrant flowers and can be found in similar growing conditions.