Mangrove swamps are common on the coasts.
There are undrained, swampy districts in Campeche, in the vicinity of the Terminos Lagoon, where malarial diseases are prevalent, and the same conditions prevail along the coast where mangrove swamps are found.
The Coastal Plain Region is the only part of the state that has any lakes, and these are chiefly shallow bodies of water, with sandy bottoms, in the midst of swamps.
In the swamps are the bald cypress, the white cedar and the live oak, usually draped in southern long moss; south of Cape Fear river are palmettos, magnolias, prickly ash, the American olive and mock orange; along streams in the Coastal Plain Region are the sour gum, the sweet bay and several species of oak; but the tree that is most predominant throughout the upland portion of this region is the long-leaf or southern pine.
The mangrove swamps at the north-west end of the harbour have been drained and partially built over.