It undoubtedly gives the seedlings a better chance of survival in a harsh environment. In Florida, red mangroves are shrubs or small trees, averaging 20 feet in height. Leaves are opposite, eggshaped to elliptical, leathery and shiny dark green above and paler underneath. Leaf edges are smooth and somewhat thickened. Clusters of 3 to 4 pale yellow flowers can be seen in the spring.
Black mangroves grow closer to the shore where they are reached only by high tides.
At the northern edge of their range, St. Augustine and Cedar Key, these trees are small and shrub-like. Larger trees up to 50 feet tall with a branch spread of 35 feet have been located further south around Sanibel-Captiva Islands. Black mangroves can be easily identified by the numerous pencil-like breathing tubes, called pneumatophores, which grow vertically from the mud to just above the highest sustained water level. Like the prop roots of the red mangrove, these provide air to the underground and underwater roots. The tops and underside of the leaves are often coated with salt crystals eliminated by the tree.