There aren’t a lot of trees that bloom year round, but one that comes to mind is the Butterfly Orchid Tree (Bauhinia divaricata). This tree blooms year round with white wispy flowers that fade to pink, and is an excellent nectar source for butterflies, especially, the Giant Swallowtail. As a bonus, in the winter, the ruby-throated hummingbird also finds it an excellent nectar source. The tree has a nice umbrella crown shape and grows to about 20 feet.
Richard Lyons’ Nursery currently has this tree in stock.