Physiognomy and Structure: This vegetation is primarily dominated by perennial grasses, but examples may have scattered to patchy trees and shrubs. Most examples occur on circumneutral soils, or other unusual substrates (clay, gravels, saline soils, etc.).

Floristics: The typical perennial grasses that dominate examples of this vegetation include Andropogon gerardii, Schizachyrium scoparium, and Sorghastrum nutans. Moist to wetter swales or zones may be embedded within and among the typical stands; in these areas, Andropogon gerardii and/or Panicum virgatum will have greater importance (DeSelm and Murdock 1993), and Tripsacum dactyloides may be present. Among the most frequent trees in the Jackson Purchase barrens include Quercus marilandica, Quercus stellata, and Quercus velutina (Bryant and Martin 1988). Dominant plants in stands of this group vary across this broad region. There are several subregional types and variability among these which is expressed in the associations. Typical trees (whose cover may be sparse) include Carya illinoinensis, Carya myristiciformis, Juniperus virginiana var. virginiana, Maclura pomifera (within its native range), Quercus muehlenbergii, Quercus pagoda, Quercus shumardii, Quercus sinuata, and Quercus stellata. Some typical shrubs and small trees include Cercis canadensis var. canadensis, Crataegus spp., Diospyros virginiana, Forestiera ligustrina, Frangula caroliniana, Ilex decidua, Prunus angustifolia, Rhus copallinum, Rhus aromatica, Rosa setigera, Sideroxylon lycioides, Symphoricarpos orbiculatus, and Ulmus alata. Other grasses and graminoids may include Bouteloua curtipendula, Carex cherokeensis, Carex microdonta, Fimbristylis puberula var. puberula, Leersia virginica, Muhlenbergia capillaris, Panicum anceps, Panicum flexile, and Sporobolus compositus. Forbs (which vary across the broad geographic range) may include Allium canadense var. mobilense, Dalea candida, Dalea purpurea, Desmanthus illinoensis, Desmodium ciliare, Echinacea pallida, Echinacea purpurea, Liatris aspera, Liatris squarrosa, Liatris squarrulosa, Lythrum alatum, Manfreda virginica, Marshallia caespitosa, Nemastylis geminiflora, Packera tampicana, Ratibida pinnata, Silphium integrifolium, Silphium laciniatum, Silphium terebinthinaceum, Silphium trifoliatum var. latifolium, Solidago auriculata, Symphyotrichum dumosum (= Aster dumosus), Symphyotrichum patens (= Aster patens), Symphyotrichum lanceolatum var. lanceolatum (= Aster lanceolatus), Thelesperma filifolium, and Zigadenus nuttallii. Some more western taxa that are present in West Gulf Coastal Plain examples are Acacia angustissima, Dalea compacta var. compacta, Dracopis amplexicaulis, Euphorbia bicolor, Eustoma exaltatum ssp. russellianum (= Eustoma russellianum), Grindelia lanceolata, Indigofera miniata (= Indigofera miniata var. leptosepala), Neptunia lutea, Onosmodium bejariense var. occidentale (= Onosmodium occidentale), Palafoxia reverchonii, Rudbeckia missouriensis, and Stenosiphon linifolius.

Dynamics:  Much of the natural vegetation of the Black Belt region (and the rest of the inner coastal plain as well) has been converted to pasture and agricultural uses, with concomitant destruction of most prairie remnants (DeSelm and Murdock 1993). Of the approximately 100,000 acres of Blackland Prairies mapped during the general land surveys of the early and mid 1800s in Mississippi, probably less than 500 acres of Jackson Prairie vegetation exists today, even if one considers grazed areas and vacant agricultural lands with a semblance of prairie species (R. Wieland pers. comm.). Almost all of the lands were converted to agriculture. Some of the lands are now reverting back to prairie after being abandoned. More recently, lands are being converted to fescue pasture; other abandoned lands have become stands of eastern red-cedar. The number of acres in good condition is probably less than 100.

In western Tennessee and Kentucky (the "Jackson Purchase" or "Jackson Plain" barrens), a number of early reports mentioned extensive prairies and emphasized the importance of annual fires in maintaining these grasslands (Bryant and Martin 1988). Scattered groves of fire-tolerant oaks were likely interspersed among these grasslands (M. Evans pers. comm.). With fire suppression, groves of trees rapidly expanded and largely replaced the prairies. In the Black Belt (and in other areas as well), the presence of Juniperus virginiana-dominated zones may represent invasion by this species in the absence of sufficiently frequent or intense fire (DeSelm and Murdock 1993). Fire return time is variable (and speculative in some cases), but fires were probably frequent (potentially on a two- to five-year return interval), originating from lightning or human ignition origin, and are thought to have occurred in late summer to early autumn prior to European settlement. Under current conditions, individual prairie openings or barrens are small and isolated from one another but were formerly more extensive prior to European settlement, forming a more extensive mosaic of grassland and woodlands under frequent fire regimes. Some proposed factors which have functioned to maintain the openness of this vegetation following the reduction of fire frequency include the droughty soils (with clay, chalk, gravel) and resulting stresses to vegetation, as well as some occasional fire. Fralish et al. (1999) noted that both post oak and chestnut oak woodlands are essentially the result of fire suppression in the barrens and historic savannas. In some areas, where the soils are particularly harsh (droughty, nutrient-poor, and/or rocky), stands may retain an open aspect in the absence of fire. Some of the extant examples are largely dependent on contemporary management regimes.