Bog relict These boggy, acidic, weakly minerotrophic peatlands occur south of the Tension Zone within a matrix of "southern" vegetation. Bog relicts are isolated from the more extensive, better-developed and much more widespread stands of this community found in the northern part of the state. Acidophiles present can include sphagnum mosses (Sphagnum spp), sedges (e.g., few seeded sedge, Carex oligosperma), ericaceous shrubs, and insectivorous herbs. Tamarack (Larix laricina) is usually the most common tree and poison-sumac (Toxicodendron vernix) is often formidably abundant in the understory, especially in the moat (or "lagg") at the upland/wetland interface. Examples in southeastern Wisconsin are all somewhat alkaline and may resemble "shrub-fen" communities described in other states.
Muskeg Muskegs are cold, acidic, sparsely wooded northern peatlands with composition similar to the Open Bogs (Sphagnum spp. Mosses, Carex spp., and ericaceous shrubs), but with scattered stunted trees of black spruce (Picea mariana) and tamarack (Larix laricina). Plant diversity is typically low, but the community is important for a number of boreal bird and butterfly species, some of which are quite specialized and not found in other communities.
Patterned peatland Very rare in Wisconsin, this wetland type can be characterized as a herb- and shrub-dominated minerotrophic peatland with alternating moss and sedge-dominated peat ridges (strings) and saturated and inundated hollows (flarks). These are oriented parallel to the contours of a slope and perpendicular to the flow of groundwater. Within a patterned peatland the peat “landforms” differ significantly in nutrient availability and Ph. The flora may be quite diverse and includes many sedges of bogs and fens, along with ericads, sundews, orchids, arrow-grasses (Triglochin spp.), and calciphilic shrubs such as bog birch (Betula pumila) and shrubby cinquefoil (Potentilla fruticosa).