These open, acidic, low nutrient peatlands occur within the Central Sand Plains of Wisconsin. Central poor fens are floristically depauperate and generally sedge dominated (Carex oligosperma, C. lasiocarpa, and C. utriculata). Bluejoint grass (Calamagrostis canadensis) is a frequent associate and may co-dominate some stands. Sphagnum moss carpets are common but typically lack pronounced hummocks and hollows. Shrubs are present but not dominant, hard-hack (Spiraea tomentosa) is the most consistent in presence, and cover of ericads is generally low. Other characteristic associates include wool grass (Scirpus cyperinus), cotton-grasses (Eriophorum spp.), swamp-candles (Lysimachia terrestris), and Kalm's St. John's-wort (Hypericum kalmianum). A zone of northern tall shrubs is sometimes present, composed of black chokeberry (Aronia melanocarpa, hollys (Ilexspp.), and bog birch (Betula pumila). This community often intergrades with northern tamarack swamp or black spruce swamp. Disturbance of this community through mossing may significantly alter community composition, as recolonization by at least some of the vascular plants is very slow. Many plants characteristic of poor fen communities farther north are rare or absent in these central sands peatlands.
