Jacaranda (Jacaranda mimosifolia) and poinciana (Delix regia) trees both have delicate, fern-like foliage, but the leaves on the poinciana are larger. Both are large trees with vase-like to spreading canopies that create light dappled shade. Both also grow well in urban areas and can be used in parking lots and along streets without sidewalks. Since both trees drop flower and seed litter, they are not good near patios, decks or walkways.
Each jacaranda leaf measures 8 to 15 inches long and is bi-pinnate, which means it is composed of major and minor leaflets. It has 13 to 25 pairs of major leaflets arranged alternately along the midrib. Each major leaflet consists of 13 to 25 smaller or minor leaflets. The leaflets are less than 2 inches long and vary from rhomboid, or diamond-shaped, to obovate with the broadest part of the leaflet just above its middle. The leaves are green with lighter green undersides and turn brown in the fall. Jacaranda grows in U.S. Department of Agriculture plant hardiness zones 9b through 11.
A poinciana leaf is also bi-pinnate, with 10 to 20 pairs of major leaflets alternately growing along the mid-rib. Each major leaflet is finely divided into 25 to 35 pairs of minor leaflets, which gives it a finer texture than the jacaranda leaves. Each oblong leaflet is less than 2 inches long. The leaf has a green upper surface and a paler green lower surface. Poinciana trees are semi-evergreen or deciduous with brown foliage in the fall. Poinciana, also called flamboyant tree, grows in USDA zones 10b through 11.
Difference in Flowers
Both trees have showy flowers that cover the tree when they bloom. The jacaranda has 1-inch, trumpet-shaped, lavender-blue flowers that grow in dense clusters 6 to 10 inches long. The lightly fragrant flowers bloom in the spring, sometimes before the leaves appear, and into the summer. The poinciana has large clusters of brilliant red-orange flowers in early summer and midsummer. Each flower has five petals up to 2 inches long; one petal is streaked with yellow and white.
Jacaranda is a fast-growing tree that reaches 25 to 40 feet tall and wide at maturity. The arching trunk has thin, grayish-brown bark that becomes scaly with age. It has light reddish-brown twigs that zigzag slightly, and thorns. Flat, round, woody, reddish-brown capsules contain numerous small, winged seeds. Poinciana also grows fast and reaches 35 to 40 feet tall and 40 to 60 feet wide with a symmetrical flat-crowned canopy. It has many branches with smooth, gray bark, reddish-brown twigs and thorns. The woody seedpod grows 2 inches wide and 14 to 20 inches long and turns reddish-brown to nearly black when ripe.