Smooth Buckwheat - Eriogonum salsuginosum
State Rank Reason (see State Rank above)
This species is on the northern 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
Score1-2 - Small to Moderate. Population size is imprecisely known but is believed to be >2,000 individuals and <100,000 individuals.
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).
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.
Score1-2 - Moderate to High Vulnerability.
Raw Conservation Status Score
10 to 15 total points scored out of a possible 16 (Rarity factors and threats only).
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.
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.
Carbon County, MT, south through UT, WY, CO, NV, AZ and NM.
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(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.
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).
- Additional ReferencesLegend: View Online Publication
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- 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. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.