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Arabis mcdonaldiana

Eastw.

Red Mountain Rockcress

G3Vulnerable Found in 12 roadless areas NatureServe Explorer →
G3VulnerableGlobal Rank
High - mediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.132067
Element CodePDBRA06150
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusArabis
Synonyms
Arabis macdonaldianaEastw.
Other Common Names
McDonald's Rockcress (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.
Taxonomic Comments
There is some disagreement about the spelling of the species epithet. According to the Jepson Flora Project (2014, 2021) "Alice Eastwood published Arabis mcdonaldiana in Bulletin of the Torrey Botanical Club 30:488-490 (1903), stating "It is named in honor of Captain James M. McDonald, to whom botanists of the Pacific coast are indebted for his generosity in publishing Greene's West American Oaks", and that consultation of Greene's work, Illustrations of West American Oaks (1889), confirms the spelling as McDonald". In Flora of North America (vol. 7, 2010), Baldwin et al. (2012), and the International Plant Names Index (2021) the epithet is spelled 'mcdonaldiana'. In contrast, Kartesz (1994, 1999) and USDA Plants (2021) spell the epithet 'macdonaldiana'. USFWS has used both spellings, but most recently on ECOS (USFWS 2021) 'macdonaldiana'. The rationale for 'macdonaldiana'. appears to be that Critchfield (1977) altered the spelling to 'macdonaldiana' following Recommendation 73C.4 of the International Code of Botanical Nomenclature (USFWS 1984). Regarding the taxonomic treatment used by USFWS, the recovery plan (USFWS 1984) makes it clear that A. mcdonaldiana does not include A. serpentinicola. Other treatments, such as Kartesz (1994, 1999), Flora of North America (vol. 7, 2010), and Baldwin et al. (2012), include A. serpentinicola in A. mcdonaldiana.
Conservation Status
Rank MethodLegacy Rank calculation - Excel v3.1x
Review Date2015-12-14
Change Date2015-12-14
Edition Date2015-12-14
Edition AuthorsBittman, R.L., rev. Maybury (1997), rev. R. Bittman (2006), rev. A. Treher (2015)
Threat ImpactHigh - medium
Range Extent5000-20,000 square km (about 2000-8000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Restricted to serpentine areas and known from 30-40 sites in northern California (Mendocino, Del Norte and Siskiyou counties) and immediately adjacent southwestern Oregon. Some populations are threatened by mining of the nickel-rich soils of its habitat and encroachment of woody vegetation. Many sites are on USFS lands, but none may be in permanent protection.
Range Extent Comments
Occurs in the Siskiyou mountains of Curry and Josephine counties, Oregon. In California, the species is reported from Del Norte, Mendocino, Siskiyou, and Trinity counties.
Occurrences Comments
California has 29 occurrences, 4 of which are historic. Oregon has 10 occurrences but one is historic.
Threat Impact Comments
Mining is the greatest threat (CNPS 2001, CNDDB 2003). The California Natural Diversity Database reports that grazing was observed at one occurrence (2003). This situation was unchanged in January 2006. Lack of fire, which leads to competition from woody vegetation, is a threat.
Ecology & Habitat

Description

A short-lived perennial plant, usually about 4-12 inches tall, with pink to purple flowers borne at or near the ends of the stalks. Stem leaves, 2-8, simple and entire; basal leaves, spatulate, appearing smooth and shiny, slightly toothed, forming a rosette. Seeds pods about 1.5 inches long.

Habitat

Rocky serpentine areas or reddish soils derived from serpentinite. In dry open woods or brushy steep slopes or ledges. Usually at elevations of about 1200 m.
Terrestrial Habitats
Forest/WoodlandForest - ConiferForest - MixedWoodland - ConiferWoodland - MixedShrubland/chaparralBarrens
Other Nations (1)
United StatesN3
ProvinceRankNative
OregonS1Yes
CaliforniaS3Yes
Threat Assessments
ThreatScopeSeverityTiming
3 - Energy production & miningPervasive - largeExtreme - seriousUnknown
3.2 - Mining & quarryingPervasive - largeExtreme - seriousUnknown

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Plant Characteristics
Economic Value (Genus)No
Roadless Areas (12)
California (9)
AreaForestAcres
Indian CreekKlamath National Forest5,011
KellySix Rivers National Forest5,195
Monkey CreekSix Rivers National Forest9,017
North Fork SmithSix Rivers National Forest37,898
PacksaddleSix Rivers National Forest3,862
SiskiyouKlamath National Forest54,039
Siskiyou ASix Rivers National Forest1,017
Siskiyou BSix Rivers National Forest18,871
South KalmiopsisSix Rivers National Forest321
Oregon (2)
AreaForestAcres
North KalmiopsisSiskiyou National Forests91,560
South KalmiopsisSiskiyou National Forests104,477
South Dakota (1)
AreaForestAcres
Indian CreekBuffalo Gap National Grassland24,666
References (15)
  1. Baldwin, B. G., D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, eds. 2012. The Jepson manual: vascular plants of California. 2nd edition. University of California Press, Berkeley, CA. 1568 pp.
  2. California Department of Fish and Game. 2000. Natural Diversity Database (RareFind 2), Version 2.1.2, January 25, 2000. Downloaded in 2003.
  3. California Native Plant Society (CNPS). 2001. Inventory of Rare and Endangered Plants of California (sixth edition). Rare Plant Scientific Advisory Committee, David P. Tibor, Convening Editor. California Native Plant Society. Sacramento, CA. x + 388pp.
  4. Critchfield, W.B. 1977. Rare plant status report: <i>Arabis macfonaldiana </i>Eastw. prepared for the California Native Plant Society, Berkeley, California.
  5. 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.
  6. Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
  7. International Plant Names Index (IPNI). 2021. Online. Available: http://www.ipni.org. (Accessed 2021).
  8. Jepson Flora Project (eds.) 2021. Jepson eFlora. Online. Available: https://ucjeps.berkeley.edu/eflora/ (accessed 2021).
  9. 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.
  10. 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.
  11. Skinner, M.W., and B.M. Pavlik, eds. 1994. California Native Plant Society's Inventory of rare and endangered vascular plants of California. 5th edition. California Native Plant Society, Sacramento. 338 pp.
  12. USDA, Natural Resources Conservation Service, PLANTS Database [USDA PLANTS]. http://plants.usda.gov/. Accessed 2021.
  13. U.S. Fish and Wildlife Service. 2021. Environmental Conservation Online System (ECOS). Online. Available: https://ecos.fws.gov/ecp/ (accessed 2021).
  14. U.S. Fish and Wildlife Service (USFWS). 1978. Determination of five plants as endangered species. Federal Register 43(189): 44810-44812.
  15. U.S. Fish and Wildlife Service (USFWS). 1984. McDonald's Rock-Cress Recovery Plan (<i>Arabis mcdonaldiana </i>Eastwood). U.S. Fish and Wildlife Service, Portland, Oregon. [https://ecos.fws.gov/docs/recovery_plan/840228.pdf]