Swamps are wetlands with a canopy of trees or shrubs. They include forested floodplains along major rivers that are temporarily flooded in spring. Northern Minnesota and Wisconsin have extensive black ash and northern white cedar swamps on saturated, peaty soils of ancient lake basins. Shrub dominated swamps include "tag Alder" thickets and those composed of willows and dogwoods.

Marshes are wetlands composed of cattails, lake sedges, burlrushes, wild rice, arrowheads and other herbaceous vegetation growing in shallow water that may be seasonal to permanent. This example is of Deep Marsh Rice Lake National Wildlife Refuge.

Bogs are wetlands with acidic, peaty soils and a carpet of Sphagnum mosses. Growing on the mossy mat are sedges, orchids, pitcher plants, evergreen shrubs and often scrubby black spruce and tamarack trees.

Fens are wetlands supported by upwelling groundwater flows creating springs and seepages. Mineral-rich, alkaline, peaty soils are saturated throughout the growing season. These include calcareous fens, the rarest wetland type in Minnesota and Wisconsin and which support a disproportionate number of rare plant species.

Wet or sedge meadows are wetlands composed of sedges, grasses and wildflowers growing on saturated soils.