Mangroves have been enormously successful in the future. With the lowering of the sea level, their possible range was greatly expanded, and large areas of the Oceanic rainforests are swampy enough for mangroves to grow in. With deeper areas becoming inshore lakes in the rainforests, mangroves had yet another new habitat to colonize.
Rhizophora (Anthropocene Red Mangroves)Edit
Rhizophora is the genus of "true mangroves" that exists in our time period. These mangroves have changed little, only increasing the concentration of tannin in an example of directional selection.
The only mangrove in this genus that has undergone dramatic evolution is the red mangrove, and the original species is very much thriving. The descendants of the red mangrove have split off into their own genus, Rhizobathus.
Rhizobathus (Deep-Water Mangroves)Edit
In five million years, the deep-water mangroves have evolved from the red mangrove (Rhizophora mangle), which is notable for having propagules that are, basically, fully formed plants that sprout as soon as they embed in a substrate, such as sand. Deep-water mangroves take that to the next level, with huge propagules with weighted ends. These propagules can reach up to a meter long, and can grow if only the tip is poking out of the water, even if waves wash over it.
The initial growth period of the deep-water mangrove lasts several days and is as fast as bamboo; the mangrove expends almost all of its stored energy in its period of rapid growth, by which point it has established a decent root system, several branches, and a good many leaves.
The next period of life is by far the most dangerous for a young mangrove: It must survive the inevitable attentions of mangrove termites (Coptotermes aigialos), a species of termite that is drawn to the scent of tannins in the water and has evolved an immunity to them. The termites are capable of walking on water, and chew into the wood, then bring it back to the nest. Mangrove termites actually use the tannins to make themselves mildly toxic (and very foul-tasting), lending them a reddish hue.