If you’ve ever been on a Florida beach, you may have seen strange cigar-shaped or lima bean-shaped pods floating in the water or lying on the sand. Although they may look alien, they’re actually the seeds of our native mangrove trees, looking to take root in some prime, beachfront real estate.
The mangrove tree is one of the more unique and important plants in Florida. We have three main varieties: the red, black, and white mangrove. What’s immediately unusual about the mangrove is that it grows in (or near) saltwater or salt marsh. That’s because Florida mangroves either exclude or excrete salt depending on the species. The black mangrove excretes salt, and you can actually find salt crystals on its leaves.
Some mangrove seeds, like the ones from the black mangrove, above, begin sprouting while still attached to the parent plant. These ‘propagules’ fall off into the water, waiting to arrive at a shallow spot where they can take root. Sometimes you’ll see them attempting to take root on a crowded beach – not a good idea!
The roots of mangroves are also unique. The NOAA describes them as “a dense tangle of prop roots that make the tree appear to be standing on stilts above the water.” That probably describes the red mangrove best – it’s also the species that tolerates salt the best, living closest to the shoreline. The roots of all types of mangroves – whether above ground or in shallow water – allow them to take in oxygen in low-oxygen marshes and estuaries. The long, leggy roots also help the trees withstand wind and waves, which in turn protects the shorelines they inhabit.
Although I identify mangroves with Florida, there are reportedly about 80 species of mangroves in tropical or subtropical areas all over the world. Everywhere you find them – Australia, the Americas, Asia, and Africa – mangrove forests protect shorelines from erosion and maintain habitats for many species of animals, like this fiddler crab at right, living in a mangrove forest next to Ponce Inlet.