Perched dunes share the foredune, blowout, backdune forest, and interdunal wetland found on the parabolic dunes, and most of the discussion of these zones under parabolic dunes is relevant to the perched dunes as well. Many of the rare plants and animals of the parabolic dunes, including Pitcher’s thistle, Lake Huron tansy, clustered broom rape, and the Lake Huron locust are also common within the perched dunes. Two rare plants that are especially common on the perched dunes are dunewort and clustered broom rape, both disjunct from the western United States.
Beaches associated with perched dunes, lying beneath steep, eroding bluffs, are often much narrower than their parabolic dune counterparts. During periods of high Great Lakes water levels, the lake’s water can be directly eroding the bluffs. Even though the beaches can be quite narrow, piping plovers are known to nest on the beaches below the perched dunes, as at Sleeping Bear Dunes National Lakeshore.
Steep eroding bluffs of till form the base from which the perched dunes rise. For both the Grand Sable dunes on Lake Superior and the Sleeping Bear dunes on Lake Michigan, the bluffs are responsible for roughly 300 feet of elevation, while the perched dunes formed on the bluff are only half that height.
On some bluff faces fine-textured banding results in numerous seepages. Trees and shrubs establish on the bluff faces, but continual erosion of the bluff base results in widespread instability.