Print Report

A1815 Sporobolus neglectus - Sporobolus vaginiflorus Alkaline Bedrock Annual Grassland Alliance

Type Concept Sentence: This alliance consists of graminoid-dominated vegetation of annual grasses Sporobolus neglectus, Sporobolus vaginiflorus var. vaginiflorus, and/or Sporobolus vaginiflorus var. ozarkanus. It is found on shale, calcareous (limestone and dolostone) and mafic (diabase) glades in the unglaciated southeastern United States.


Common (Translated Scientific) Name: Barrens Dropseed - Poverty Dropseed Alkaline Bedrock Annual Grassland Alliance

Colloquial Name: Southern Annual Grass Glade

Hierarchy Level:  Alliance

Type Concept: This alliance consists of annual graminoid-dominated vegetation found on shale, calcareous (limestone and dolostone) and mafic (diabase) glades in the unglaciated southeastern United States, not including similar vegetation on outcrops in the Coastal Plain. These glades are dominated by the annual grasses Sporobolus neglectus, Sporobolus vaginiflorus var. vaginiflorus, and/or Sporobolus vaginiflorus var. ozarkanus. Other annual grasses and forbs are often prominent as well. This vegetation is dominated by early-flowering species that complete their life cycles before the glades dry up in the early summer, as well as fall-flowering annual grasses (e.g., Sporobolus clandestinus).

Diagnostic Characteristics: These glades of calcareous, shale or mafic rock outcrops are dominated by the annual grasses Sporobolus neglectus, Sporobolus vaginiflorus var. vaginiflorus, and/or Sporobolus vaginiflorus var. ozarkanus. Other annual grasses and forbs are often prominent as well.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Similar vegetation found on outcrops in the Coastal Plain are not included here. There are difficult conceptual issues related to how to classify calcareous glade communities, which are characteristically physiognomic complexes of annual-dominated grasses and forbs, perennial-dominated grasses and forbs, shrubs, and woodlands.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: These glades are dominated by the annual grasses Sporobolus neglectus, Sporobolus vaginiflorus var. vaginiflorus, and/or Sporobolus vaginiflorus var. ozarkanus. Other annual grasses and forbs are often prominent as well.

Floristics: In the southeastern United States, this alliance consists of calcareous (limestone and dolostone) and mafic (diabase) glades dominated by the annual grasses Sporobolus neglectus, Sporobolus vaginiflorus var. vaginiflorus, and/or Sporobolus vaginiflorus var. ozarkanus (= Sporobolus ozarkanus). Other annual grasses and forbs are often prominent as well. In Arkansas, associated species include Echinacea pallida, Echinacea paradoxa var. paradoxa, Echinacea simulata, Lithospermum canescens, and Penstemon cobaea. In Tennessee, some of the co-occurring perennial forbs are the endemic or near-endemic Dalea gattingeri and Pediomelum subacaule, along with Croton capitatus, Grindelia lanceolata, Stenaria nigricans (= Hedyotis nigricans), Heliotropium tenellum, Trichostema brachiatum (= Isanthus brachiatus), Manfreda virginica, and Ruellia humilis. Vegetation of the Arkansas Upper West Gulf Coastal Plain nepheline syenite glades is dominated by species such as Amsonia ciliata var. ciliata, Astragalus distortus (var. engelmannii, var. distortus), Clinopodium arkansanum (= Calamintha arkansana), Cheilanthes lanosa, Chamaesyce missurica (= Euphorbia missurica), Oenothera linifolia, Phacelia hirsuta, Plantago pusilla, Sabatia campestris, Salvia azurea, Schizachyrium scoparium, Sporobolus clandestinus, and Phemeranthus calycinus (= Talinum calycinum). Nonvasculars include Cladonia spp. (lichens), Grimmia spp. (mosses), and Nostoc spp. (blue-green algae).

Dynamics:  This vegetation is dominated by early-flowering species that complete their life cycles before the glades dry up in the early summer, as well as fall-flowering annual grasses.

Environmental Description:  This alliance consists of annual graminoid-dominated vegetation found on calcareous (limestone and dolostone) and mafic (diabase) glades in the unglaciated southeastern United States. This vegetation is dominated by early-flowering species that complete their life cycles before the glades dry up in the early summer, as well as fall-flowering annual grasses.

Geographic Range: This alliance is found in the southeastern and south-central United States from Arkansas to northern Alabama, Tennessee, Kentucky and east to the Piedmont of North Carolina.

Nations: US

States/Provinces:  AL, AR, GA, KY, NC, OK?, TN, VA




Confidence Level: Low

Confidence Level Comments: No Data Available

Grank: GNR

Greasons: No Data Available


Concept Lineage: equivalent to A.1815 with edits

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Vegetation on soil, grass stage Aristida longispica - Sporobolus sp. zone (Quarterman 1950a)
= Xeric Limestone Prairie (shallow soil areas) (Lawless et al. 2006)

Concept Author(s): A.S. Weakley and M. Pyne, in Faber-Langendoen et al. (2013)

Author of Description: C. Nordman

Acknowledgements: E. Quarterman''s work has laid the foundation of what we know about these habitats.

Version Date: 09-26-14

  • Baskin, J. M., and C. C. Baskin. 1996. The Grindelia lanceolata plant community type in cedar glades of the Central Basin of Tennessee. Castanea 61:339-347.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Foti, T., compiler. 1994b. Natural vegetation classification system of Arkansas, draft five. Unpublished document. Arkansas Natural Heritage Commission, Little Rock. 8 pp.
  • Gallyoun, M., G. Meyer, A. Andreu, and W. Slocumb. 1996. Mapping vegetation communities with The Nature Conservancy''s vegetation classification system on five small national parks in the southeastern USA. Unpublished report. The Nature Conservancy, Southeast Regional Office, Conservation Science Department, Chapel Hill, NC.
  • Lawless, P. J., J. M. Baskin, and C. C. Baskin. 2006. Xeric limestone prairies of eastern United States: Review and synthesis. The Botanical Review 72(3):235-272.
  • Pell, W. F., and J. H. Rettig, compiler. 1983. Arkansas natural community abstracts. Arkansas Natural Heritage Commission, Little Rock. 37 pp.
  • Quarterman, E. 1950a. Major plant communities of Tennessee cedar glades. Ecology 31:234-254.
  • Rogers, C. L., M. J. Ratnaswamy, and R. J. Warren. 1993. Vegetation communities of Chickamauga Battlefield National Military Park, Georgia. Technical Report NPS/SERCHCH/NRTR-93-11. National Park Service, Southeastern Region, Atlanta, GA. 83 pp.
  • Rollins, S. C. 1997. Calcareous glade communities in the Central Basin of Tennessee: The effects of scale on community classification. M.S. thesis, University of North Carolina, Chapel Hill. 142 pp.
  • Somers, P., editor. 1986. Symposium: Biota, ecology, and ecological history of cedar glades. ASB Bulletin 33:123-221.
  • TNC [The Nature Conservancy]. 1996a. Ecological assessment: Alcoa Bauxite Natural Areas in Arkansas: A report on the status of Natural Areas with stewardship recommendations. The Nature Conservancy, Arkansas Field Office, Little Rock. 57 pp.