The floodplains , which are flooded for several months each year , feature sedges such as spike rush as well patches of freshwater mangroves ( itchy tree ) , pandanus and paper bark trees ( Melaleuca ) . The floodplains , which are inundated for several months each year , feature sedges such as spike rush as well patches of freshwater mangroves ( itchy tree ) , pandanus and paper bark trees ( Melaleuca ) .