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Montana Field Guides

Smooth Buckwheat - Eriogonum salsuginosum
Other Names:  Stenogonum salsuginosum

Species of Concern
Native Species

Global Rank: G4?
State Rank: S1S2
(see State Rank Reason below)
State Threat Score: Unknown
CCVI: Moderately Vulnerable

Agency Status


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State Rank Reason (see State Rank above)
This species is on the southern edge of its range in south-central Montana, where it has been documented from only two small areas on the south side of the Pryor Mountains. There is active bentonite mining in the immediate vicinity of one of the known occurrences. Follow-up visits are needed to document the extent of the populations and to monitor population trends.
  • Details on Status Ranking and Review
    Smooth Buckwheat (Eriogonum salsuginosum) Conservation Status Review
    Review Date = 06/04/2012
    View State Conservation Rank Criteria
    Population Size

    Score1-2 - Small to Moderate. Population size is imprecisely known but is believed to be >2,000 individuals and <100,000 individuals.

    Range Extent

    Score3 - Local Endemic or Very Small Montana Range: Generally restricted to an area <10,000 sq. miles (equivalent to the combined area of Phillips and Valley Counties) or <6 Sub-basins (4th code watersheds) Range-wide OR limited to one Sub-basin in Montana

    Area of Occupancy

    Score3 - Very Low: Generally occurring in 3 or fewer Subwatersheds (6th Code HUC’s).

    Environmental Specificity

    Score1-2 - Moderate to High.


    ScoreNA - Rank factor not assessed.


    Score1-3 - Medium to Very High. Threats exist, but severity, scope and/or immediacy are uncertain.

    CommentBentonite mining may threaten populations in Montana.

    Intrinsic Vulnerability

    Score1-2 - Moderate to High Vulnerability.

    Raw Conservation Status Score

    Score 10 to 15 total points scored out of a possible 16 (Rarity factors and threats only).

General Description
Smooth buckwheat is a small annual that often branches at the base. Its stems up to 15 cm high. The mainly basal leaves are 5-30 mm long are and spoon-shaped with a broad petiole, while the stem leaves may be sessile. The foliage is glabrous. The small yellow flowers have 6 lance-shaped perianth segments that are 1-3 mm long. Flowers are borne in a cup formed of 2 whorls of 3 tiny bracts each, or an involucre. The involucres are borne in an open, dichotomously-branched inflorescence located at the top of the stem. The seeds are ca. 2 mm long.

Flowering occurs in June.

Diagnostic Characteristics
There are only three other annual species of Eriogonum in Montana: E. annuum and E. cernuum have densely hairy foliage. The involucral bracts of E. visheri are united into a cup, while those of E. salsuginosum are deeply divided and nearly separate from each other. Eriogonum salsuginosum is sometimes placed in the separate genus Stenogonum.

Species Range
Montana Range Range Descriptions


Range Comments
Carbon County, MT, south through UT, WY, CO, NV, AZ and NM.

Observations in Montana Natural Heritage Program Database
Number of Observations: 7

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

In the Pryor Mountains, this plant grows on bentonite in dry, open slopes of breaklands, at about 1430 m (4700 feet) (Lesica and Achuff 1992). Associated species include Monolepis nuttalliana, Musineon divaricatum, Halogeton glomeratus, Camissonia scapoidea and Platyschkuhria integrifolia. At another site, it was found on a dry, open ridge midslope with Atriplex gardneri, Artemisia pedatifida, Kochia sp., Artemisia tridentata, Agropyron spicatum, Poa secunda, Stipa comata, Oryzopsis hymenoides, Platyschkuhria integrifolia, Opuntia polyacantha, Heterotheca villosa, and Allium textile.
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habitat Model available.

To learn how these Models were created see

Ecological Systems Associated with this Species

Because this species is an annual, population sizes may vary greatly from year to year depending on environmental conditions. The plant's small size and sparsely vegetated habitat suggest that it is a poor competitor for light. The small flower size suggests that it is self-pollinated.

Disturbance that reduces competition from larger plants will likely benefit smooth buckwheat. Bentonite mining exists in the immediate vicinity of known populations (Lesica and Achuff 1992).

Threats or Limiting Factors
Reported threats to Montana's populations of Smooth Buckwheat are potential impacts from bentonite mining (MTNHP Threat Assessment 2021). Few populations occupying sparsely vegetated bentonite rich soils are at potential risk of a range of disturbances from direct displacement to indirect impacts that reduce habitat quality. Mining activity and associated road building are likely to invite threats related to non-native species invasions, subsequent herbicide weed control, and other long-term consequences of fragmented habitat. Information on the scope, severity, and/or timing of threats to Smooth Buckwheat are needed to assess a relative risk from impacts.

  • Literature Cited AboveLegend:   View Online Publication
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Lesica, P. and P.L. Achuff. 1992. Distribution of vascular plant species of special concern and limited distribution in the Pryor Mountain desert, Carbon County, Montana. Unpublished report to the Bureau of Land Management. Montana Natural Heritage Program, Helena, MT. 105 pp.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
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Citation for data on this website:
Smooth Buckwheat — Eriogonum salsuginosum.  Montana Field Guide.  .  Retrieved on , from