by Kyle Sweet, The Sanctuary Golf Club, Florida Master Naturalist
Shiny, glossy, pointy green leaves that are green on top and bottom of the leaf
Numerous reddish arching aerial roots called prop roots
Small four petal yellowish flowers
Reproduces by long dangling propagules that are 6-8” in length
A true Florida native, the Red Mangrove, Rhizopora mangle , is one of the just a few mangroves found in the United States. The Red Mangrove is arguably the most recognizable and best known of all of the mangroves. The name Red Mangrove comes from the bright red color of the wood underneath the bark of the tree.
The Red Mangrove can be seen growing up to 50’ tall on our local barrier islands. It has adapted aerial “prop roots” to help hold the tree steady in its soft, muddy environment. In addition to support, these prop roots also have tiny pores all throughout them that transport air to the trees saturated, below ground roots. These very visible roots are also effective in trapping sediment and debris. This buildup of material eventually builds up soil around the plants and often create mangrove islands out away from land. These islands serve as excellent habitat for roosting and nesting birds as well as for mangrove tree crabs. Red Mangroves are sometimes called “walking trees” for this reason, as the aerial prop roots emerging from the water in shallow water make them look like they are walking on water.
The Red Mangrove has small, yellow flowers that are pollinated by the wind. A pollinated flower becomes a seed, which actually grows its first rot while still attached to the parent tree. These seeds germinate, looking like green and brown cigars, and remain hanging on the tree. These “propagules” grow to a length of around 8”and eventually drop off. Once in the water, it can float for up to a year with the rooting tip of the propagule pointing downward and will hopefully come to rest in the soil, rooting from the bottom tip and sprouting leaves from the top.
Other mangroves found throughout Sanibel and Captiva include the Black mangrove, Avicennia germinans and the White mangrove, Laguncularia racemosa . These can be both all throughout the same habitat as the Red mangrove and along with the Red mangrove form an incredibly important ecosystem on our barrier islands. The submerged roots of the Red mangrove provide a nursery habitat to many fish and crustaceans as well as habitat for several mammals, birds and reptiles. All of the mangroves contribute to the protection of the shoreline by acting as a buffer to reduce wave action, prevent erosion and absorb floodwaters.