Identity
Unique IDELEMENT_GLOBAL.2.159159
Element CodePDPAP02020
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderPapaverales
FamilyPapaveraceae
GenusArctomecon
Other Common Namescommon bearpoppy (EN) Common Bearpoppy (EN) Dwarf Bearclaw-poppy (EN)
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 Date2024-05-09
Change Date1983-07-18
Edition Date2024-05-09
Edition AuthorsGreene, L., rev. D. Atwood, rev. B. Franklin (1996), rev. L. Oliver (2013), rev. J. Johnson (2024)
Threat ImpactVery high
Range Extent250-1000 square km (about 100-400 square miles)
Number of Occurrences6 - 20
Rank ReasonsArctomecon humilis is narrowly endemic to Washington County, Utah, USA. It is known from nine populations. The species' habitat is in an area of rapid population growth and development, and the low, barren hills on which it grows are popular areas for motorized and non-motorized recreation. Climate change may reduce opportunities for new plant establishment and ex-situ conservation has proven unsuccessful. Loss of a specialist pollinator and low gene flow between populations are also threats.
Range Extent CommentsArctomecon humilis is endemic to the Triassic Moenkopi Formation (Schnabkaib, especially, but also on Middle and Upper Red members) in mixed warm desert shrub communities in Washington County, Utah, USA. Range extent was estimated using herbarium specimens and NatureServe Network occurrence data collected between 1993 and 2024 and the USFWS 5-year review (UNHP 2021, USFWS 2022, NatureServe 2024, SEINet 2024).
Occurrences CommentsUsing a 2 km separation distance, there are nine occurrences (UNHP 2021, USFWS 2022).
Threat Impact CommentsArctomecon humilis occurs within a 10km radius of the city of St. George, which has undergone urban development and road construction that has fragmented or removed habitat for this species (Nelson and Harper 1991, Allphin et al. 1998). Approximately 300 acres of occupied habitat have been lost to development since 1990, and six populations are all or partially subject to development (USFWS 2022). Off-road vehicles are also a threat since the gypsum shale where this species occurs is attractive to users. The vehicles not only destroy plants, cause soil erosion, crush the dominant cryptogamic crusts found strongly associated with the dwarf bear poppy, but they also damage viable seed (Nelson and Harper 1991). Off-road vehicle use within populations has decreased since 2013 due to the fencing of populations on BLM land and the acquisition of the White Dome and Shinob Kibe populations by The Nature Conservancy (USFWS 2022).
Livestock grazing at the Beehive Dome population is extensive and may be responsible for the loss the Mojave poppy bee (Perdita meconis), a specialist pollinator of Arctomecon humilis that nests in soil. Invasive plant threats are low in most populations due to the gypsum soil, but coverage of Bromus tectorum and Bromus rubens is increasing in the White Dome population. Threats from gypsum mining and horticultural collection have decreased throughout the range of the species (USFWS 2022). Climate change is expected to increase the severity and frequency of droughts in this region. Because this plant only establishes in consecutive years of above-average precipitation (USFWS 2022), this will likely cause fewer opportunities for new plants to replace deceased plants.