M.E. Jones
Identity
Unique IDELEMENT_GLOBAL.2.131836
Element CodePDFAB0F820
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderFabales
FamilyFabaceae
GenusAstragalus
Concept ReferenceKartesz, 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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-04-04
Change Date2025-04-04
Edition Date2025-04-04
Edition AuthorsB. Franklin, rev. M. McCormick (2024) and N. Ventrella (2025)
Threat ImpactUnknown
Range Extent250-1000 square km (about 100-400 square miles)
Number of Occurrences6 - 20
Rank ReasonsAstragalus serpens is a perennial forb occurring on igneous gravels of the Marysvale volcanic region in sagebrush, pinyon-juniper, aspen, and aspen-fir communities in Piute, Sevier, and Wayne counties, Utah. It is an uncommon edaphic endemic known from an estimated eleven occurrences, though plant numbers can be abundant in favorable years. Primary threats to this species are from habitat degradation due to grazing, vegetation treatments, drought, and road maintenance, though the severity of impacts are largely unknown. Many occurrences are considered historical and should be revisited.
Range Extent CommentsAstragalus serpens occurs in the western United States in the Marysvale Volcanic region of south-central Utah (FNA 2023). Specifically, it is a Southern Plateaus endemic found in Piute, Sevier, and Wayne counties (Welsh et al. 2015). Range extent was calculated using data from the Utah Rare Plant Database (2024), excluding observations over 40 years old (UNHP 2024).
Occurrences CommentsBy applying a 2 km separation distance to herbarium records documented between 1994 and 2025, it is estimated that there are five occurrences rangewide (RARECAT 2025, SEINet 2025). However, the Utah Natural Heritage Program estimates that there are eleven occurrences using population location data from the Utah Rare Plant Database (2024) and applying the same separation distance (UNHP 2024).
Threat Impact CommentsThreats were compiled using observations and notes from the Utah Rare Plant Database (2024) and Utah Geospatial Resource Center data (2024). Major threats to Astragalus serpens are habitat degradation due to grazing, vegetation treatments, drought, and road maintenance (UNHP 2024). However, the severity of impacts are not well known (UNPS 2025).
All occurrences occur within grazing allotments (UNHP 2024). Future wind and solar development may impact some occurrences within the boundaries of Utah's Renewable Energy Zone (UREZ). Many occurrences are near minor roads. Past and on-going vegetation treatments to reduce woody plant cover such as pinyon-juniper removal are occurring within habitat for this species, though it's unclear how these actions are impacting Astragalus serpens. Drought and climate change is also a threat, and is likely impacting this species throughout its range (Wrobleski et al. 2023).