Some plants are even adapted to the soil and water of one type of wetland. That's why many wetland plant species are considered rare, threatened, or endangered. They're very specific about their habitats, and those habitats have been disappearing for 150 years. There are many types of wetlands. Some are classified by from where the water comes.
Water can come from two places.
Many seasonal and semi-permanent wetlands, and some permanent wetlands, fill with rain or melted snow. The other souce of water is groundwater. Groundwater-fed wetlands are usually permanent wetlands. Sometimes it is hard to tell where a wetland gets its water. In Iowa we have palustrine , lacustrine and riverine wetland types.