Print Report

A3321 Andropogon virginicus - Ambrosia artemisiifolia - Conyza canadensis Eastern Ruderal Grassland Alliance

Type Concept Sentence: This alliance encompasses herbaceous vegetation for which no natural analog exists, that is found in the eastern United States. Examples are composed of native and/or exotic species and are found on sites that were cleared and the soils disturbed (e.g., old fields, abandoned quarries, old homesteads).

Common (Translated Scientific) Name: Broomsedge Bluestem - Annual Ragweed - Canadian Horseweed Eastern Ruderal Grassland Alliance

Colloquial Name: Eastern Ruderal Grassland

Hierarchy Level:  Alliance

Type Concept: This alliance encompasses a variety of herbaceous vegetation that occurs in the eastern United States on sites that were cleared and the soils disturbed (e.g., old fields, abandoned quarries, old homesteads). Stands are composed of combinations of native and/or exotic species for which no natural analog exists. These species include Ambrosia artemisiifolia, Andropogon virginicus var. virginicus, Conyza canadensis, Cynodon dactylon, Eremochloa ophiuroides, Eupatorium spp., Imperata cylindrica, Schedonorus arundinaceus, Schedonorus pratensis, Paspalum notatum, Pennisetum glaucum, Solidago spp., Sorghum halepense, Stenotaphrum secundatum, and Urochloa ramosa. Scattered shrubs may be present, including Rhus copallinum. In the southeastern Piedmont, the herbs and grasses that dominate old fields undergo a rapid turnover in the first three years after abandonment. By the third year, Andropogon virginicus often is the dominant plant. Before it achieves dominance, Ambrosia artemisiifolia, Conyza canadensis, Digitaria sanguinalis, and Symphyotrichum pilosum may be more prominent; other combinations of native and exotic species also may occur.

Diagnostic Characteristics: This alliance encompasses a variety of native- and exotic-dominated herbaceous vegetation that occurs on disturbed sites in the eastern United States. There may be no clear dominant, and the sites may undergo year-to-year changes in composition and dominance as succession occurs.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Stands of this alliance are composed of combinations of taxa for which no natural analog exists. One significant reference is Wright and Fridley (2010), from which more information can be obtained on regional variation in semi-natural vegetation in the eastern United States.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: Examples of this diverse alliance may be dominated by stands of, or combinations of, a variety of native and exotic grasses and forbs. Andropogon virginicus var. virginicus is often the dominant plant by the third year of succession in Piedmont old fields (Oosting 1942). Before it achieves dominance, Ambrosia artemisiifolia, Conyza canadensis, Digitaria sanguinalis, and Symphyotrichum pilosum may be more prominent. Other species that may be present include Ambrosia artemisiifolia, Conyza canadensis, Cynodon dactylon, Eremochloa ophiuroides, Imperata cylindrica, Schedonorus arundinaceus (= Lolium arundinaceum), Schedonorus pratensis (= Lolium pratense), Paspalum notatum, Pennisetum glaucum, Sorghum halepense, Stenotaphrum secundatum, and Urochloa ramosa. In the Piedmont of North Carolina, other (mostly native) herbaceous taxa may include Antennaria plantaginifolia, Bulbostylis capillaris, Chamaecrista fasciculata, Chamaesyce nutans, Cyperus compressus, Diodia teres, Eupatorium capillifolium, Eupatorium compositifolium, Eupatorium serotinum, Fimbristylis autumnalis, Gamochaeta purpurea (= Gnaphalium purpureum), Helenium amarum (= Helenium tenuifolium), Hypericum drummondii, Hypericum gentianoides, Ipomoea lacunosa, Ipomoea pandurata, Juncus tenuis, Plantago aristata, Pseudognaphalium obtusifolium (= Gnaphalium obtusifolium), Solanum carolinense, and Solidago spp. (Oosting 1942). Scattered shrubs may be present, including Rhus copallinum. In the southeastern Piedmont, the herbs and grasses that dominate old fields undergo a rapid turnover in the first three years after abandonment. There may be no clear dominant, and the sites may undergo year-to-year changes in composition and dominance as succession occurs (Oosting 1942).

Dynamics:  In the southeastern Piedmont, the herbs and grasses that dominate old fields undergo a rapid turnover in the first three years after abandonment. By the third year, Andropogon virginicus often is the dominant plant. There may be no clear dominant, and the sites may undergo year-to-year changes in composition and dominance as succession occurs (Oosting 1942).
Environmental Description:  No Data Available
Geographic Range: This vegetation is found across the eastern United States, in the coastal plains and the unglaciated interior provinces.

Nations: BS,PR,US

States/Provinces:  AL, AR, FL, GA, IL, IN, KY, LA, MD, MO, MS, NC, OK, SC, TN, TX, VA, WV


Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available
Grank: GNA

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Nh Southeastern North American Grassland & Shrubland Division D102 2.B.2.Nh
Macrogroup 2.B.2.Nh.90 Broomsedge Bluestem - Blackberry species - Annual Ragweed Southeastern Ruderal Grassland & Shrubland Macrogroup M307 2.B.2.Nh.90
Group 2.B.2.Nh.90.a Broomsedge Bluestem - Annual Ragweed - Sawtooth Blackberry Ruderal Grassland & Shrubland Group G583 2.B.2.Nh.90.a
Alliance A3321 Broomsedge Bluestem - Annual Ragweed - Canadian Horseweed Eastern Ruderal Grassland Alliance A3321 2.B.2.Nh.90.a
Association CEGL004035 Winged Sumac - Broomsedge Bluestem Ruderal Grassland CEGL004035 2.B.2.Nh.90.a
Association CEGL004044 Broomsedge Bluestem Ruderal Grassland CEGL004044 2.B.2.Nh.90.a
Association CEGL004048 (Tall Fescue, Meadow Fescue) Ruderal Grassland CEGL004048 2.B.2.Nh.90.a
Association CEGL004108 Johnson Grass Ruderal Grassland CEGL004108 2.B.2.Nh.90.a
Association CEGL004673 Cogongrass Ruderal Grassland CEGL004673 2.B.2.Nh.90.a
Association CEGL004700 Bahia Grass Ruderal Grassland CEGL004700 2.B.2.Nh.90.a
Association CEGL004701 Bermuda Grass Eastern Ruderal Grassland CEGL004701 2.B.2.Nh.90.a
Association CEGL004883 St. Augustine Grass Ruderal Grassland CEGL004883 2.B.2.Nh.90.a
Association CEGL008453 Browntop-millet Ruderal Grassland CEGL008453 2.B.2.Nh.90.a
Association CEGL008454 Pearl-millet Ruderal Grassland CEGL008454 2.B.2.Nh.90.a
Concept Lineage: The associations placed here come from a variety of old alliances, most of which only had one member association; A.1139 (1/1), A.1208 (1/3), A.1213 (1/2), A.1215 (1/1), A.1219 (1/1), A.1279 (1/1), A.2000 (1/1), and A.2020 (1/3).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Herblands of abandoned fields; Andropogon virginicus, Eupatorium compositifolium (Penfound 1967)
> Herblands of abandoned fields; Digitaria sanguinalis, Erigeron canadensis (Penfound 1967)
> Seral grasslands on abandoned fields; Andropogon virginicus (Penfound 1967)
Concept Author(s): M. Pyne, in Faber-Langendoen et al. (2013)

Author of Description: M. Pyne

Acknowledgements: We have incorporated significant descriptive information previously compiled by Carl Nordman, Judy Teague and Alan Weakley.

Version Date: 03-14-14
  • 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.
  • Oosting, H. J. 1942. An ecological analysis of the plant communities of Piedmont, North Carolina. The American Midland Naturalist 28:1-127.
  • Penfound, W. T. 1967. A physiognomic classification of vegetation in conterminous United States. Botanical Review 33:289-320.
  • Wright, J. P., and J. D. Fridley. 2010. Biogeographic synthesis of secondary succession rates in eastern North America. Journal of Biogeography 37:1584-1596.