Mimosa-like leaves consist of a feather-like stem lined with many small leaflets, also known as a pinnately compound leaf, and are indicative of many trees in the large legume family, Fabaceae. Orange flowers on leguminous trees are less common than other colours, and such trees typically hail from subtropical or tropical regions. Keep in mind that colour is subjective, as some may think orange is more red, and certain light may cause flower colour to change in tint or intensity.
Also called flamboyant tree, the royal poinciana (Delonix regia) is often called the world's most beautiful flowering tree by horticulturists, according to Learn2Grow. Native to Madagascar but grown all around the tropics today, royal poinciana's feathery green leaves make a soft foil for the vibrant orange, five-petaled, claw-like flowers that occur in late spring and early summer. After flowering, long, dark brown seed pods dangle from the tree's branches.
Naturalised as a weed in the southeastern U.S., rattle box (Sesbania punicea) has origins in southern South America. Rattle box tolerates salt spray and brackish water as well as good garden soil. Usually attaining a shrubby, small tree shape, rattle box's branch tips produce dropping clusters of orange to scarlet pea-shaped flowers anytime in the warmth of summer and early fall. The ensuing seed pods are four-winged, according to Kirsten Albrecht Llamas, author of "Tropical Flowering Plants."
The national flower of Barbados, pride-of-Barbados (Caesalpinia pulcherrima) is also called dwarf poinciana and is native to Central America, not the Caribbean. A leggy, shrublike small tree, its branches bear thorns. Anytime from spring to fall, the branch tips bear circular clusters of reddish flowers with ruffled yellow edges; collectively, they look orange from a distance. Great variation exists among plants, as some produce flowers with all-yellow, all red-orange or white-edged red petals, according to Albrecht Llamas. Black swallowtail butterflies flock to the blossoms for nectar.
Closely related and similar in appearance to the royal poinciana is Colville's glory (Colvillea racemosa). Also native to Madagascar, a key identifying characteristic of Colville's glory is that it blooms in autumn with long, spirelike orange flower clusters on branch tips. Each flower bud is orange, but when open reveals a mass of golden stamens. By the tropical winter or spring, flat, woody seed pods dangle from the branch tips and split open.