The inhabitants of the intertidal areas in the tropics and
subtropics, mangroves are a collection of curious plants. It
is easy to make the wrong assumption that different types of mangroves
are closely related species adapted to the particular conditions in
which they grow.
Even
the English common names (red mangrove, black mangrove, white mangrove,
buttonwood mangrove, etc.) lend themselves to the idea that they are
merely different species of the same plant family as if it were maple or
oak.
In
fact, mangroves are a wonderful example of convergent evolution a
situation in which unrelated organisms have evolved certain
similarities, just because it is more appropriate to use a particular
resource. And
in this case, the resource is a place in which a plant can grow if it
can overcome two major difficulties faced by mangroves: the salinity of
sea water that saturates the soil and grow in the absence of oxygen
saturation in the same mud .