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Phacelia tetramera

J.T. Howell

Dwarf Phacelia

G4Apparently Secure Found in 3 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.136692
Element CodePDHYD0C4K0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderSolanales
FamilyHydrophyllaceae
GenusPhacelia
Other Common Names
Four-part Phacelia (EN) fourpart phacelia (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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-06-25
Change Date1988-05-16
Edition Date2024-06-25
Edition AuthorsJohnson, J. (2024)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Phacelia tetramera is a small annual plant that is found across the Great Basin and north into eastern Washington in the western United States. With a large range extent, over 30 occurrences, and preferences for abundant habitat, this species is apparently secure.
Range Extent Comments
Phacelia tetramera ranges from eastern Oregon to California and east to Utah and Wyoming. Range extent was estimated using herbarium specimens and photo-based observations documented between 1993 and 2024 (GBIF 2024, iNaturalist 2024, SEINet 2024, OSU 2024). Historical collections exist in northeastern Oregon and central Washington, but these have not been observed recently (GBIF 2024, SEINet 2024, OSU 2024).
Occurrences Comments
By applying a 1 km separation distance to herbarium records and photo-based observations documented between 1993 and 2024, it is estimated that there are between 21 and 80 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024, OSU 2024).
Threat Impact Comments
Although threats are not widely documented, Phacelia tetramera is potentially threatened by development, road maintenance, invasive species, livestock grazing, changes to natural fire cycles, and other threats in some places. However, their overall impact is likely negligible given species' broad range, large number of occurrences, tolerance of light disturbance, and affinity for typically abundant habitats, as well as no obvious intrinsic vulnerabilities.
Ecology & Habitat

Habitat

Phacelia tetramera is found in sagebrush steppe communities, meadows, vernal pools, alkaline flats, swales, and washes. It grows in salt-encrusted soil, alkaline clay and fine silt, and
cracked bare alkaline silt in vernally moist wetlands (Wildflower Center 2021, WNHP 2024).
Terrestrial Habitats
Shrubland/chaparralGrassland/herbaceousPlaya/salt flatBarrens
Palustrine Habitats
TEMPORARY POOL
Other Nations (1)
United StatesN4
ProvinceRankNative
NevadaS3Yes
WyomingS1Yes
WashingtonS1Yes
OregonS2Yes
CaliforniaSNRYes
UtahS1Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undeterminedUnknownUnknownUnknown
1 - Residential & commercial developmentUnknown——
2 - Agriculture & aquacultureUnknown——
2.3 - Livestock farming & ranchingUnknown——
4 - Transportation & service corridorsUnknown——
4.1 - Roads & railroadsUnknown——
7 - Natural system modificationsUnknown——
7.1 - Fire & fire suppressionUnknown——
8 - Invasive & other problematic species, genes & diseasesUnknown——
8.1 - Invasive non-native/alien species/diseasesUnknown——

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Plant Characteristics
DurationANNUAL
Economic Value (Genus)No
Roadless Areas (3)
California (3)
AreaForestAcres
Excelsior (CA)Inyo National Forest45,607
Glass MountainInyo National Forest52,867
WattersonInyo National Forest6,922
References (4)
  1. Cronquist, A., A. H. Holmgren, N. H. Holmgren, J. L. Reveal, and P. K. Holmgren. Intermountain Flora, Vascular Plants of the Intermountain West, U.S.A. Volume Four: Subclass Asteridae (except Asteracea). The New York Botanical Garden, Bronx, N.Y. 573 pp.
  2. 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.
  3. Washington Natural Heritage Program (WNHP). 2024. Online Field Guide to the Rare Plants of Washington. Online. Available: https://fieldguide.mt.gov/wa (accessed 2024).
  4. Wildflower Center. 2021. Native Plant Database: <i>Phacelia tetramera</i>. Lady Bird Johnson Wildflower Center, University of Texas, Austin. Accessed: September 23, 2022. https://www.wildflower.org/plants/result.php?id_plant=PHTE