April-May means that the frangipani is in bloom. Its scientific name is Plumeria rubra with common names: Frangipani and Temple Tree (because it can usually be seen at temple sites in Asia.) I really like the scent of these flowers which is there all the time. You pick a flower, and the scent is right there... very unlike the elusive scent from its relative, the Alstonia scholaris. Yes, both are in the same family of Apocynaceae. You can guess judging from the similarity in the structure of their leaves and the form of their flowers. But I value the scent of A. scholaris far better... simply because it is much harder to come by.