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CEGL001449 Eriogonum thymoides / Poa secunda Dwarf-shrub Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Thymeleaf Buckwheat / Sandberg Bluegrass Dwarf-shrub Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This plant association is most commonly observed in east-central Washington, though it is disjunct in southwestern Idaho. It is restricted to shallow silt loam and stony loam lithosolic soil underlain by basalt. It commonly forms a mosaic with ~Artemisia rigida / Poa secunda Shrub Grassland (CEGL001528)$$ and other Eriogonum spp.-dominated types (e.g., ~Eriogonum strictum / Poa secunda Dwarf-shrub Grassland (CEGL001788)$$) with which it may intergrade. The association is characterized by the presence of the low-shrub Eriogonum thymoides (with up to about 15% cover) over a ground layer of Poa secunda (with up to about 40% cover). Perennial forbs, especially Allium spp., Lomatium spp., Phlox hoodii, Nestotus stenophyllus, and Viola beckwithii, are common. The association lacks Artemisia rigida but may include significant amounts of Eriogonum douglasii or Eriogonum sphaerocephalum growing with the indicator species Eriogonum thymoides.
This plant association is described for the Columbia Plateau of southeastern Washington. Stands are also known from the upper Hells Canyon in Idaho. The association occurs on basalt Lithosol sites ranging in elevation of 640 to 945 m (2100-3100 feet) on the Columbia Plateau and 975-1250 m (3200-4100 feet) in the upper Hells Canyon region. Stands are relatively open. Eriogonum thymoides dominates the dwarf-shrub canopy. Poa secunda is consistently the most abundant grass species; Elymus elymoides is typically also present. Perennial forbs are diverse and varied. Particularly constant forbs include Antennaria flagellaris, Lithophragma glabrum, Lewisia rediviva, and Phoenicaulis cheiranthoides.
This plant association is described for the Columbia Plateau of southeastern Washington. Stands are also known from the upper Hells Canyon in Idaho. The association occurs on basalt Lithosol sites ranging in elevation of 640 to 945 m (2100-3100 feet) on the Columbia Plateau and 975-1250 m (3200-4100 feet) in the upper Hells Canyon region. Stands are relatively open. Eriogonum thymoides dominates the dwarf-shrub canopy. Poa secunda is consistently the most abundant grass species; Elymus elymoides is typically also present. Perennial forbs are diverse and varied. Particularly constant forbs include Antennaria flagellaris, Lithophragma glabrum, Lewisia rediviva, and Phoenicaulis cheiranthoides.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Though a distinct type, this plant association sometimes intergrades with ~Artemisia rigida / Poa secunda Shrub Grassland (CEGL001528)$$ (Daubenmire 1970). Stands with Artemisia rigida and Eriogonum thymoides present are classified as Artemisia rigida / Poa secunda Dwarf-shrub Herbaceous Vegetation. It is structurally similar to other lithosolic plant associations, such as ~Eriogonum douglasii / Poa secunda Dwarf-shrub Grassland (CEGL001785)$$ and ~Eriogonum sphaerocephalum / Poa secunda Dwarf-shrub Grassland (CEGL001448)$$, with which it may also intergrade (Daubenmire 1970). Daubenmire (1970) classified one stand codominated by Eriogonum thymoides and Eriogonum sphaerocephalum as the Eriogonum thymoides / Poa secunda association. The Eriogonum sphaerocephalum / Poa secunda association has only trace cover and constancy of Eriogonum thymoides.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: The association is characterized by the presence of the low-shrub Eriogonum thymoides (with up to about 15% cover) over a ground layer of Poa secunda (with up to about 40% cover). Perennial forbs, especially Allium spp., Lomatium spp., Phlox hoodii, Nestotus stenophyllus (= Stenotus stenophyllus), and Viola beckwithii, are common. The association lacks Artemisia rigida but may include significant amounts of Eriogonum douglasii or Eriogonum sphaerocephalum growing with the indicator species Eriogonum thymoides. Particularly constant forbs include Antennaria flagellaris, Lithophragma glabrum (= Lithophragma bulbiferum), Lewisia rediviva, and Phoenicaulis cheiranthoides.
Dynamics: No Data Available
Environmental Description: This plant association is described for the Columbia Plateau of southeastern Washington and the upper Hells Canyon in Idaho where it occurs on basalt Lithosol sites ranging in elevation of 640 to 945 m (2100-3100 feet) on the Columbia Plateau and 975-1250 m (3200-4100 feet) in the upper Hells Canyon region. It is restricted to shallow silt loam and stony loam lithosolic soil underlain by basalt.
Geographic Range: The association is known from only southeastern Washington and west-central Idaho.
Nations: US
States/Provinces: ID, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.684414
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: G3
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 3 Desert & Semi-Desert Class | C03 | 3 |
| Subclass | 3.B Cool Semi-Desert Scrub & Grassland Subclass | S11 | 3.B |
| Formation | 3.B.1 Cool Semi-Desert Scrub & Grassland Formation | F033 | 3.B.1 |
| Division | 3.B.1.Ne Western North American Cool Semi-Desert Scrub & Grassland Division | D040 | 3.B.1.Ne |
| Macrogroup | 3.B.1.Ne.2 Little Sagebrush - Black Sagebrush - Scabland Sagebrush Steppe & Shrubland Macrogroup | M170 | 3.B.1.Ne.2 |
| Group | 3.B.1.Ne.2.a Scabland Sagebrush - Buckwheat species Dwarf-shrubland & Steppe Group | G307 | 3.B.1.Ne.2.a |
| Alliance | A1568 Buckwheat species / Sandberg Bluegrass Dwarf-shrub Steppe Alliance | A1568 | 3.B.1.Ne.2.a |
| Association | CEGL001449 Thymeleaf Buckwheat / Sandberg Bluegrass Dwarf-shrub Grassland | CEGL001449 | 3.B.1.Ne.2.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Eriogonum thymoides - Poa secunda Habitat Type (Daubenmire 1970) [has only trace cover and constancy of Eriogonum thymoides.]
- Bourgeron, P. S., and L. D. Engelking, editors. 1994. A preliminary vegetation classification of the western United States. Unpublished report. The Nature Conservancy, Western Heritage Task Force, Boulder, CO. 175 pp. plus appendix.
- Daubenmire, R. F. 1970. Steppe vegetation of Washington. Washington State University Agricultural Experiment Station Technical Bulletin No. 62. 131 pp.
- IDCDC [Idaho Conservation Data Center]. No date. Unpublished data on file at Idaho Conservation Data Center, Department of Fish and Game, Boise, ID.
- WNHP [Washington Natural Heritage Program]. 2018. Unpublished data files. Washington Natural Heritage Program, Department of Natural Resources, Olympia, WA.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.