The major ecosystems include mangrove and freshwater swamps and marshes, sedge prairie, pine savanna, and gallery forest.
There is a diverse amount of flora, estimated at over 2,000 species of vascular plants, although little has been written about it because many species are new or undiscovered.

There are two major mangrove ecosystems along the coast: the Brus Lagoon and the Iban Lagoon.
The Brus area is 120 km² and brackish, and the Ibans area is 63 km² and freshwater.
The mangroves are valuable and fragile, so they are a significant part of the value of the reserve.

Further in, the land becomes prairie and savannah with pine and palm, depending upon the availability of water.
 Along the watershed of the rivers, the vegetation is thick wet forest, which is again, poorly studied.
The major ecosystems include mangrove and freshwater swamps and marshes, sedge prairie, pine savanna, and gallery forest. There is a diverse amount of flora, estimated at over 2,000 species of vascular plants, although little has been written about it because many species are new or undiscovered.
There are two major mangrove ecosystems along the coast: the Brus Lagoon and the Iban Lagoon. The Brus area is 120 km² and brackish, and the Ibans area is 63 km² and freshwater. The mangroves are valuable and fragile, so they are a significant part of the value of the reserve.
Further in, the land becomes prairie and savannah with pine and palm, depending upon the availability of water.  Along the watershed of the rivers, the vegetation is thick wet forest, which is again, poorly studied.
Río Plátano Biosphere Reserve