Piedmont Flatwoods (Upland Depression Swamps)
These flatwoods, often called Iredell flatwoods (based on the soils they form upon), Gabbro glades, upland depression swamps, and Monticello glades (due to their location near Monticello, GA), form on flat to gently sloping land over gabbro mafic rocks (and perhaps on some shales). In winter and spring, when rainfall is high, the soils swell to form an impermeable surface, creating a perched wetland. In summer and fall, the soils shrink and become almost pavement-like. These extremes of water levels, along with the nutrients and high pH of the mafic soil, support unique plant assemblages of forests interspersed with small openings that support a variety of wetland and mesophytic plant species.
Indicator species: Carolina shagbark hickory, red hickory, eastern redbud, green ash, Shumard oak, Oglethorpe oak, saw palmetto, Atamasco lily
What's special: In the spring, these sites are beautiful when swathes of Atamasco lilies bloom along with eastern redbud, and flowering dogwood. Saw palmetto, parsley haw and buckthorn bumelia add Coastal Plain elements, and the rare Oglethorpe oak grows in the flatwoods.
Conservation: Upland depression wetlands are very rare in the Georgia Piedmont; gabbro is an unusual surface rock. The unique variety of plant species they support justifies conserving all examples that can be found. Some ecologists recommend prescribed fire to create more prairies over gabbro rock, which would support further rare species.
Related communities: Intergrades with Mesic Forests and Bottomland Forests
Click on a plant name to see images.
Red maple Acer rubrum
Musclewood Carpinus caroliniana
Eastern redbud/American hornbeam Cercis canadensis
Carolina shagbark hickory Carya carolinae-septentrionalis
Red hickory Carya ovalis
Flowering dogwood Cornus florida
White ash Fraxinus americana
Green ash Fraxinus pennsylvanica
Eastern red cedar Juniperus virginiana
Sweetgum Liquidambar styraciflua
Black gum Nyssa biflora
Overcup oak Quercus lyrata
Swamp chestnut oak Quercus michauxii
Water oak Quercus nigra
Oglethorpe oak Quercus oglethorpensis
Cherrybark oak Quercus pagoda
Willow oak Quercus phellos
Shumard oak Quercus shumardii
Winged elm Ulmus alata
Slippery elm Ulmus rubra
Buttonbush Cephalanthus occidentalis
Fringetree Chionanthus virginicus
Parsley haw Crataegus marshallii
Possumhaw Ilex decidua
Winterberry Ilex verticillata
Saw palmetto Serenoa repens
Buckthorn bumelia Sideroxylon lycioides
American rattan Berchemia scandens
Crossvine Bignonia capreolata
Trumpet creeper Campsis radicans
Carolina jessamine Gelsemium sempervirens
Whiteleaf greenbrier Smilax glauca
Common greenbrier Smilax rotundifolia
Poison ivy Toxicodendron radicans
Ground Layer Forbs
Carolina windflower Anemone caroliniana
Spring beauty Claytonia virginica
Partridgeberry Mitchella repens
False garlic Nothoscordum bivalve
Kidney-leaved grass-of-Parnassus Parnassia asarifolia
Early meadowrue Thalictrum dioicum
Atamasco lily Zephyranthes atamasco
Christmas fern Polystichum acrostichoides
Grasses, Sedges, and Rushes
River cane Arundinaria gigantea
Witchgrasses Dichanthelium spp
Cutgrasses Leersia spp.
Sedges Carex spp.
Representative Trees in order by scientific name
Representative Shrubs in order by scientific name.
Representative vines. in order by scientific name.
Representative wildflowers in order by scientific name,
Representative Ferns, in order by scientific name
Representative Graminoids, in order by scientific name