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Arabis olympica

Piper

Olympic Rockcress

G1Critically Imperiled Found in 5 roadless areas NatureServe Explorer →
G1Critically ImperiledGlobal Rank
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.153713
Element CodePDBRA060M2
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusArabis
Synonyms
Arabis furcata var. olympica(Piper) Rollins
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
Flora of North America Editorial Committee (2010) recognizes Arabis olympica as a species distinct from A. furcata . "The striking differences in fruit width and orientation, stem indument, and seed and flower size support their maintenance as distinct species. Although both species grow in Washington, the range of A. olympica seems to be restricted to Clallam and Jefferson counties and is disjunct from Chelan, Kittitas, and Yakima counties, where A. furcata grows." (Flora of North America Editorial Committee 2010)
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2022-02-28
Change Date2022-02-28
Edition Date2022-03-01
Edition AuthorsMacBryde, Bruce (1997), rev. A. Tomaino (2014), rev. A. Tomaino (2021), rev. Treher (2022)
Threat ImpactMedium
Range Extent<100 square km (less than about 40 square miles)
Number of Occurrences1 - 5
Rank Reasons
Arabis olympica is known only from the Olympic Mountains in western Washington. It was not seen since 1980 until rediscovered in 2020 in Olympic National Forest. Thus, there is currently only one extant occurrence. Threats include climate change. Historical sites and potential habitat need further survey.
Range Extent Comments
Arabis olympica was known, historically, from the Olympic Mountains of western Washington state in Clallam, Jefferson, and Mason counties (Rollins 1993, FNA 2010). There is no known report from British Columbia (J. Penny and W. Fertig, pers. comm., 2021).
Occurrences Comments
In 2022, it was realized that the species was rediscovered in 2020 in the Olympic National Forest, representing the only extant site (W. Fertig, pers. comm., 2022). There are 6 historical occurrences with most recent, last observed in 1980 (Fertig 2020, NatureServe Network Database as of September 2021).
Threat Impact Comments
"Potentially threatened by changes to snowpack and moisture availability and changes in temperature that could increase competition from other plant species as a result of predicted climate change" (Fertig 2020). A study by Wershow and DeChaine (2018) found that other Olympic alpine endemics are likely to lose of 85-99% of their suitable habitat by 2080 based on climate change projections. Introduced mountain goats are a possible threat (Washington Natural Heritage Program 1981).
Ecology & Habitat

Habitat

This species grows in the subalpine to alpine zone, on talus slopes (FNA 2010), rocky scree, and in dry, rocky meadows and turf areas in the midst of rock outcrops (Fertig 2020). Arabis olympica is associated with Mountain Juniper (Juniperus communis), Spreading Phlox (Phlox diffusa), Scarlet Paintbrush (Castilleja miniata), and Piper's Harebell (Campanula piperi) (Washington Natural Heritage Program 1981).
Terrestrial Habitats
AlpineBare rock/talus/scree
Other Nations (1)
United StatesN1
ProvinceRankNative
WashingtonS1Yes
Threat Assessments
ThreatScopeSeverityTiming
8 - Invasive & other problematic species, genes & diseasesRestricted (11-30%)Moderate or 11-30% pop. decline—
8.1 - Invasive non-native/alien species/diseasesRestricted (11-30%)Moderate or 11-30% pop. decline—
11 - Climate change & severe weatherPervasive - largeModerate or 11-30% pop. decline—
11.1 - Habitat shifting & alterationPervasive - largeModerate or 11-30% pop. decline—

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (5)
Washington (5)
AreaForestAcres
Green MountainOlympic National Forest4,617
Jefferson RidgeOlympic National Forest6,512
LightningOlympic National Forest7,179
QuilceneOlympic National Forest18,656
Upper SkokomishOlympic National Forest9,311
References (12)
  1. Abrams, L. 1944. Illustrated flora of the Pacific states: Washington, Oregon, and California. Vol. 2. Polygonaceae to Krameriaceae. Stanford Univ. Press, Stanford, California. 635 pp.
  2. Fertig, W. 2020a. Potential federal candidate plant species of Washington. Prepared for U.S. Fish and Wildlife Service, Western Washington Fish and Wildlife Office, Region 1. Natural Heritage Report 2020-01. January 15, 2020. Washington Natural Heritage Program, Washington Department of Natural Resources Olympia, Washington. 97 pp. [https://www.dnr.wa.gov/publications/amp_nh_potential_candidate_sp.pdf]
  3. Flora of North America Editorial Committee (FNA). 2010. Flora of North America north of Mexico. Vol. 7. Magnoliophyta: Salicaceae to Brassicaceae. Oxford University Press, New York. xxii + 797 pp.
  4. Hitchcock, C.L., A. Cronquist, M. Ownbey, and J.W. Thompson. 1964. Vascular plants of the Pacific Northwest. Part 2: Salicaceae to Saxifragaceae, by C.L. Hitchcock and A. Cronquist. Univ. Washington Press, Seattle. 597 pp.
  5. Hitchcock, C.L., and A. Cronquist. 1974. Flora of the Pacific Northwest: An illustrated manual. 2nd printing, with corrections. Univ. Washington Press, Seattle. xix + 730 pp.
  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. Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
  8. Piper, C.V. 1913. New or noteworthy species of Pacific coast plants. Contributions from the United States National Herbarium 16(5): 207-210.
  9. Rollins, R.C. 1993a. The Cruciferae of continental North America: Systematics of the mustard family from the Arctic to Panama. Stanford Univ. Press, Stanford, California. 976 pp.
  10. Washington Natural Heritage Program. 1981. An illustrated guide to the endangered, threatened and sensitive vascular plants of Washington. Washington Natural Heritage Program, Olympia. 328 pp.
  11. Washington Natural Heritage Program. 1997. Endangered, Threatened and Sensitive Vascular Plants of Washington - with Working Lists of Rare Non-Vascular Species. Department of Natural Resources. Olympia. 62 p.
  12. Wershow, S. T. and E. G. DeChaine. 2018. Retreat to refugia: Severe habitat contraction projected for endemic alpine plants of the Olympic Peninsula. American Journal of Botany 105(4):760-778.