poinciana (poinsēā´nə, –ă´nə), any shrub or tree of the tropical and subtropical genus Poinciana of the family Leguminosae (pulse family). Poincianas are popular ornamentals for their showy orange or scarlet blossoms. The royal poinciana or peacock flower (P. regia), native to Madagascar, is one of the most striking of tropical trees. It is widely cultivated elsewhere, e.g., the West Indies, the S United States, and Bermuda. Poincianas are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Leguminosae.