Common (Translated Scientific) Name: Eastern Red-cedar / Little Bluestem - (Big Bluestem, Indiangrass) - Prairie Rosinweed Wooded Grassland

Colloquial Name: South-Central Limestone Hill Barrens

Hierarchy Level:  Association

Type Concept: These red-cedar / little bluestem limestone barrens have been observed on Silurian exposures of Decatur and Perry counties, Tennessee (Western Highland Rim in the Western Valley of the Tennessee River) and Mississippian exposures of the Moulton Valley of Colbert and Franklin counties of northern Alabama. The Tennessee examples occur on slopes of Silurian geology, of the Brownsport, Dixon, and Beech River formations. Two phases of this vegetation have been observed. Areas presumably of deeper soil are dominated by Andropogon gerardii, Sorghastrum nutans, and Schizachyrium scoparium. Other forbs dominant to present in this phase include Liatris aspera, Silphium terebinthinaceum, Silphium trifoliatum var. latifolium, and Brickellia eupatorioides. This vegetation covers extensive areas at one site, where very old, gnarled Juniperus virginiana var. virginiana are present at a cover of 15-20%, Mortality and/or morbidity caused by drought maintains the tree cover at below 20% even in fire-suppressed examples. This phase grades into areas of shallower soil with a sparser grass cover (about 50%), composed primarily of Schizachyrium scoparium. Also present in this more common Schizachyrium-dominated phase are Liatris cylindracea, Physostegia virginiana ssp. praemorsa, Ruellia humilis, annual Sporobolus sp., Symphyotrichum concolor, Symphyotrichum shortii, and Heliotropium tenellum. Up to 50% of the ground surface in the drier phase may be covered by red or gray fossiliferous gravel in the Tennessee examples, or by shaly, "marly" limestone fragments in Moulton Valley, Alabama, ones. State-rare plants in Tennessee examples (disjunct from farther west) include Liatris cylindracea, Symphyotrichum pratense and Salvia azurea var. grandiflora. Alabama examples (but not Tennessee ones as far as known) may contain the globally rare Eriogonum longifolium var. harperi, and may locally grade down into small seepages with Schoenolirion croceum [see ~Eleocharis (bifida, compressa) - Schoenolirion croceum - Carex crawei - Allium cernuum Seep Grassland (CEGL004169)$$]. The Tennessee sites are among the most extensive areas of Silurian surface geology in the unglaciated continental United States.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This or a closely related type occurs in Virginia on hillside calcareous glades (G. Fleming pers. comm.). This type has been compared with related vegetation in Alabama and Kentucky and its range extended. Interpretations of physiographic and ecoregional boundaries are conflicting and controversial in northwestern Alabama. This association is indisputably one which occurs on Mississippian or older strata (e.g., sedimentary limestones and soils derived from them), not on cretaceous clays. Despite this, there are some occurrences within the boundary of TNC Ecoregion 43 (Upper East Gulf Coastal Plain). Even at the finer scale of the map in Webb et al. (1997), two nearby sites are shown to occur in different "subsections" when the substrates appear to be identical in the field. The type should probably be treated as "peripheral" in Ecoregion 43.

Similar NVC Types: No Data Available

note: No Data Available