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Home/Species/ Blue Mountain Milkvetch

Astragalus tegetarioides

M.E. Jones

Blue Mountain Milkvetch

G3Vulnerable Found in 1 roadless area NatureServe Explorer →
G3VulnerableGlobal Rank
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.132582
Element CodePDFAB0F8P0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderFabales
FamilyFabaceae
GenusAstragalus
Other Common Names
Bastard Milkvetch (EN) bastard milkvetch (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic Comments
Astragalus tegetarioides was taxonomically redefined, and as now defined it is endemic to eastern Oregon and another species A. anxius was described, endemic to California (Meinke and Kaye 1992, Kartesz 1994, Oregon Flora Project 2019). This has been also named as a variety, Astragalus tegetarioides var. anxius (Welsh 1998), but A. tegetarioides and A. anxius continue to be considered as distinct species by botanists in Oregon and California, where they occur (Oregon Flora Project 2019, Wojciechowski and Spellenberg 2012).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2022-12-22
Change Date1996-01-19
Edition Date2022-12-22
Edition AuthorsGreene, L., & R. Bittman (1983), rev. C. Nordman (2022).
Threat ImpactMedium
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Endemic to Oregon. About 50 extant occurrences are limited to a small area. Suppression of wildfires has reduced the number of open, disturbed sites on which this species depends.
Range Extent Comments
Blue Mountain Milkvetch occurs in the northwestern United States, it is endemic to eastern Oregon, where it occurs in the Blue Mountains and Northern Basin and Range regions. Nearly all known locations are in Harney County and it also occurs in Crook County, Oregon. The range extent is estimated to be 4,600 square kilometers (NatureServe 2022, SEINet 2022).
Occurrences Comments
There are about 40 occurrences of Blue Mountain Milkvetch, but the number could be less, depending on the separation distance applied to the known locations (NatureServe 2022).
Threat Impact Comments
Threat impacts to Blue Mountain Milkvetch are not well known, but it may be threatened by road construction and maintenance, grazing impacts (including trampling by livestock), incompatible logging practices, and by lack of wildland fire, it may benefit from moderate intensity wildland fire, which may reduce small tree density and help maintain open woodland (NatureServe 2022).
Ecology & Habitat

Diagnostic Characteristics

Blue Mountain Milkvetch (Astragalus tegetarioides) has a prostrate habit (in clumps, with many-branched stems 2-5 cm tall, forming dense rounded mats) and tiny flowers which distinguish it from other Astragalus species (Meinke 1982, Oregon Flora Project 2019).

Habitat

Blue Mountain Milkvetch occurs on dry open ground on sandy or gravelly soil in sagebrush, open Ponderosa Pine woodland, or disturbed areas along roadsides at elevations of 1300 - 1700 meters (Meinke 1982, NatureServe 2022, Oregon Flora Project 2019, SEINet 2022).
Terrestrial Habitats
Woodland - ConiferShrubland/chaparral
Other Nations (1)
United StatesN3
ProvinceRankNative
OregonS3Yes
Threat Assessments
ThreatScopeSeverityTiming
2 - Agriculture & aquacultureRestricted (11-30%)Moderate - slightHigh (continuing)
2.3 - Livestock farming & ranchingRestricted (11-30%)Moderate - slightHigh (continuing)
4 - Transportation & service corridorsSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
4.1 - Roads & railroadsSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
5 - Biological resource useRestricted - smallSlight or 1-10% pop. declineHigh (continuing)
5.3 - Logging & wood harvestingRestricted - smallSlight or 1-10% pop. declineHigh (continuing)
7 - Natural system modificationsRestricted (11-30%)Moderate - slightHigh (continuing)
7.1 - Fire & fire suppressionRestricted (11-30%)Moderate - slightHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (1)
Oregon (1)
AreaForestAcres
Silver CreekOchoco National Forest7,952
References (8)
  1. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  2. Meinke, R.J. 1982. Threatened and Endangered Vascular Plants of Oregon: An Illustrated Guide. U.S. Fish and Wildlife Service, Region 1, Portland, Oregon. 326 pp.
  3. Meinke, R.J. and T.N. Kaye. 1992. Taxonomic assessment of Astragalus tegetarioides (Fabaceae) and a new related species from northern California. Madrono 39:193-204.
  4. NatureServe. 2022. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  5. Oregon Flora Project. 2019. August last update. Rare Plant Fact Sheets. Department of Botany & Plant Pathology, Oregon State University, Corvallis, Oregon. Online. Available: https://oregonflora.org/pages/rare-plant-factsheets.php (accessed 2022, 2025).
  6. Southwest Environmental Information Network (SEINet). 2022. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2022).
  7. Welsh, S.L. 1998. Astragalus (Leguminosae): Nomenclatural proposals and new taxa. Great Basin Naturalist 58(1):45-53.
  8. Wojciechowski, M.F. and R. Spellenberg. 2012. <i>Astragalus anxius</i>, in Jepson Flora Project (eds.) Jepson eFlora. Online. Available: https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=15132 (Accessed 2022).