Print Report

A1820 Sedum pulchellum Alkaline Bedrock Herb Alliance

Type Concept Sentence: This alliance consists of shallow-soil alkaline glades of the southeastern United States where Sedum pulchellum is characteristic and often forms dense mats.

Common (Translated Scientific) Name: Widow''s-cross Alkaline Bedrock Herb Alliance

Colloquial Name: Interior Plateau Alkaline Glade

Hierarchy Level:  Alliance

Type Concept: This alliance consists of shallow-soil glades of the southeastern United States. Sedum pulchellum is characteristic and often forms dense mats. In addition to Sedum pulchellum (which has been characterized as being annual, biennial, or perennial), the vegetation consists largely of annuals (Leavenworthia) or nonvascular plants (e.g., Nostoc, a blue-green alga or cyanobacterium). Phemeranthus calcaricus is actually a perennial. In Arkansas examples, herbaceous associates include Agrostis elliottiana, Coreopsis lanceolata, Croton michauxii var. ellipticus, Danthonia spicata, Hordeum pusillum, Plantago aristata, and Ruellia humilis. Vernal pools or depressions in the substrate which hold moisture play an important role in the dynamics and persistence of this vegetation. In Tennessee, this alliance occurs over limestone or glauconite; in Arkansas, it occurs over shale.

Diagnostic Characteristics: Herbaceous annual and perennial vegetation on shale or limestone glades in the Interior Highlands and Interior Low Plateau. Sedum pulchellum is characteristic and often forms dense mats.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Similar vegetation from Texas is classified in ~Southeastern Coastal Plain Barrens & Glade Group (G584)$$ and ~Comanchian Barrens & Glade Group (G598)$$. Type may be referred to as glade or outcrop.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: In addition to Sedum pulchellum (which has been characterized as being annual, biennial, or perennial), the vegetation consists largely of annuals (Leavenworthia) or nonvascular plants (e.g., Nostoc, a blue-green alga or cyanobacterium).

Floristics: Sedum pulchellum is characteristic and often forms dense mats. In addition to Sedum pulchellum (which has been characterized as being annual, biennial, or perennial), the vegetation consists largely of annuals (Leavenworthia) or nonvascular plants (e.g., Nostoc, a blue-green alga or cyanobacterium). Phemeranthus calcaricus (= Talinum calcaricum) is actually a perennial. In Arkansas examples, herbaceous associates include Agrostis elliottiana, Coreopsis lanceolata, Croton michauxii var. ellipticus (= Croton willdenowii), Danthonia spicata, Hordeum pusillum, Plantago aristata, and Ruellia humilis.

Dynamics:  It is prone to wetness in the winter and spring, and drought in the late summer.
Environmental Description:  This alliance consists of shallow-soil glades of the southeastern United States occurring on outcrops and very thin-soil glades of limestone or shale. Vernal pools or depressions in the substrate which hold moisture play an important role in the dynamics and persistence of this vegetation. In Tennessee, this alliance occurs over limestone or glauconite; in Arkansas, it occurs over shale.
Geographic Range: This alliance occurs in the Nashville Basin (Tennessee) and Moulton Valley (Alabama) in cedar glades and south-facing shale glades in the Ouachita Mountains of western Arkansas and perhaps eastern Oklahoma.

Nations: US

States/Provinces:  AL, AR, KY, OK?, TN


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

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.Nc Eastern North American Grassland & Shrubland Division D024 2.B.2.Nc
Macrogroup 2.B.2.Nc.3 Little Bluestem - Dropseed species Central Interior Calcareous Scrub & Grassland Macrogroup M508 2.B.2.Nc.3
Group 2.B.2.Nc.3.b Little Bluestem - Sideoats Grama - Diamond-flowers Central Glade & Barrens Group G179 2.B.2.Nc.3.b
Alliance A1820 Widow''s-cross Alkaline Bedrock Herb Alliance A1820 2.B.2.Nc.3.b
Association CEGL004346 Widow''s-cross - Limestone Fameflower - Gladecress species / Common Nostoc Limestone Glade Vegetation CEGL004346 2.B.2.Nc.3.b
Association CEGL004347 Widow''s-cross - Rockpink Fameflower - Threadleaf Evening-primrose Shale Glade Vegetation CEGL004347 2.B.2.Nc.3.b
Concept Lineage: equivalent to A.1820 with edits

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: ? Sedum pulchellum herbaceous association (Hoagland 1998a)
= Vegetation on rock, Nostoc-Talinum zone (Quarterman 1950a)
Concept Author(s): K.D. Patterson, in Faber-Langendoen et al. (2013)

Author of Description: C. Nordman and K.D. Patterson

Acknowledgements: The work of E. Quarterman and K.D. Patterson is acknowledged.

Version Date: 09-26-14
  • 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.
  • Hoagland, B. W. 1998a. Classification of Oklahoma vegetation types. Working draft. University of Oklahoma, Oklahoma Natural Heritage Inventory, Norman. 43 pp.
  • Hoagland, B. W. 1998b. The vegetation of Oklahoma: A classification for landscape mapping and conservation planning. Oklahoma Biological Survey. University of Oklahoma, Norman.
  • Quarterman, E. 1950a. Major plant communities of Tennessee cedar glades. Ecology 31:234-254.
  • 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.
  • USFWS [U.S. Fish and Wildlife Service]. 1992. White bladderpod (Lesquerella pallida) recovery plan. U.S. Fish and Wildlife Service, Albuquerque, NM. 22 pp.