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Phacelia argentea

A. Nels. & J.F. Macbr.

Silvery Phacelia

G2Imperiled Found in 1 roadless area NatureServe Explorer →
G2ImperiledGlobal Rank
Very highThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.152494
Element CodePDHYD0C070
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderSolanales
FamilyHydrophyllaceae
GenusPhacelia
Other Common Names
Sand-dune Phacelia (EN) sanddune 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 Date2021-03-31
Change Date1996-01-24
Edition Date2021-03-31
Edition AuthorsVrilakas, Sue, rev. S. Vrilakas (2006), rev. C. Nordman (2021).
Threat ImpactVery high
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences6 - 80
Rank Reasons
Phacelia argentea has few occurrences, and a fairly low number of plants. A total of 15,000 plants estimated in 2006, over a limited range in coastal Oregon and northern California. It is threatened by coastal development, coastal recreation (off-road vehicles and foot traffic) and competition from exotic plant species.
Range Extent Comments
Phacelia argentea occurs only in the northwestern United States, in southwestern Oregon along the Pacific coast of Coos and Curry counties, and in adjacent northern California, along the coast in Del Norte County, as far south as Crescent City (Kalt 2008, NatureServe Network Database as of March 2021, Oregon Department of Agriculture 2014).
Occurrences Comments
There are less than 35 locations of Phacelia argentea but some are clustered, close to each other. Based on standard separation distances, there are about 20 occurrences (Kalt 2008, NatureServe Network Database as of March 2021).
Threat Impact Comments
The main threats to Phacelia argentea are coastal development, coastal recreation (off-road vehicles and foot traffic) and competition from exotic plant species. This species does not compete well with European beachgrass (Ammophila arenaria) or gorse (Ulex europaea) invasive exotic plants which are encroaching in dunes where Phacelia argentea occurs (Kalt 2008, NatureServe Network Database as of March 2021, Oregon Department of Agriculture 2014).
Ecology & Habitat

Description

Perennial, evergreen herb with many branching stems from a flattened mat. Typically, the stems are decumbent, meaning lying or trailing on the ground with the end tending to climb. The foliage has a silvery appearance from many short appressed hairs on the leaves. The 1 to 2 inch leaves are either entire or may have two basal lobes. The surface of the leaves is deeply impressed with veins. The white flowers are in scorpioid cymes (or rounded heads) at the tip of stems. One to many cymes make up each flowering head. The five stamens are exerted. Flowers are present May through August. Fruits are produced from June through August.

Habitat

Phacelia argentea occurs on open coastal sands above the high tide line, on coastal sand dunes (stabilized or unstabilized), and on sandy bluffs. Associated plant species include Abronia latifolia, Ambrosia chamissonis, Calystegia soldanella, Camissonia cheiranthifolia ssp. cheiranthifolia, Cardionema ramosissimum, Dactylis glomerata, Festuca rubra, Fragaria chiloensis, Glehnia littoralis ssp. leiocarpa, Lupinus littoralis, Poa macrantha, Polygonum paronychia, and the exotic invasive species Ammophila arenaria and Hypochaeris radicata. (Oregon Department of Agriculture 2014).
Terrestrial Habitats
Sand/dune
Other Nations (1)
United StatesN2
ProvinceRankNative
CaliforniaS1Yes
OregonS2Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentRestricted (11-30%)Extreme or 71-100% pop. declineHigh (continuing)
6 - Human intrusions & disturbanceLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (1)
Oregon (1)
AreaForestAcres
TenmileSiuslaw National Forest10,818
References (10)
  1. Abrams, L. 1951. Illustrated flora of the Pacific states: Washington, Oregon, and California. Vol. 3. Geraniaceae to Scrophulariaceae. Stanford Univ. Press, Stanford, California. 866 pp.
  2. Edwards, Ashley Marie. 2009. The McKee Preserve Management Options at Bandon Dunes Golf Resort. Master of Environmental Management Project Reports. 13. Online. Available: https://pdxscholar.library.pdx.edu/mem_gradprojects/13 https://doi.org/10.15760/mem.25 (Accessed 2021).
  3. Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
  4. Imper, David. Botanist for USFWS Arcata office, California.
  5. Kalt, J. 2008. Status Review and Field Inventory for Silvery Phacelia: <i>Phacelia argentea</i> (Hydrophyllaceae). Report to the U.S. Fish &amp; Wildlife Service, Arcata, CA.
  6. 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.
  7. Oregon Department of Agriculture, Native Plant Conservation Program. 2014. Oregon Listed Plant Profiles: Endangered: Mulford's milkvetch (<i>Astragalus mulfordiae</i>). Online. Available: https://www.oregon.gov/oda/shared/Documents/Publications/PlantConservation/AstragalusMulfordiaeProfile.pdf (Accessed 2021).
  8. U.S. Fish and Wildlife Service (USFWS). 2015. Endangered and Threatened Wildlife and Plants; 90-Day Findings on 31 Petitions. Federal Register 80(126):37568-37579.
  9. U.S. Fish and Wildlife Service (USFWS). 2022. Threatened Species Status with Section 4(d) Rule for Sand Dune Phacelia and Designation of Critical Habitat. Proposed Rule. Federal Register 87(55):16320-16363.
  10. U.S. Fish and Wildlife Service (USFWS). 2023. Threatened Species Status With Section 4(d) Rule for Sand Dune Phacelia and Designation of Critical Habitat. Federal Register 88(161): 57180-57222.