Angsana tree is Pterocarpus indicus

Each plant usually has the same kind of leaves, flowers and fruits (with slight variations sometimes) no matter where in the world it grows. Such high consistency urged scientists to come up with scientific names for each plant, that could be consistent , so a plant is known by the same name all over the world. Interestingly these names seem quite complex to common people who find it difficult to remember these names. Hence they usually prefer to remember the common names and forgo the scientific names.