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Home/Species/ Shockley's Rockcress

Boechera shockleyi

(Munz) Dorn

Shockley's Rockcress

G3Vulnerable Found in 7 roadless areas NatureServe Explorer →
G3VulnerableGlobal Rank
Identity
Unique IDELEMENT_GLOBAL.2.142388
Element CodePDBRA061V0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusBoechera
Synonyms
Arabis shockleyiMunz
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
Treated by FNA (2010, vol. 7) in the genus Boechera.
Conservation Status
Review Date2009-02-04
Change Date1988-08-03
Edition Date1999-05-27
Edition AuthorsGries, D., rev. K. Gravuer (2009)
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences21 - 300
Rank Reasons
Known from the mountains of the northern Mojave Desert and Great Basin in eastern California, Nevada, and western Utah. Approximately 66 occurrences have been mapped and are presumed extant, and an additional 14 are historical; it is very likely that more occurrences will be recorded with further survey and mapping effort. Population size in Nevada, which contains about half of known occurrences, has been estimated at 745+ plants. Prefers limestone and, to a lesser extent, quartzite substrates; concentration in calcareous areas has rendered the species vulnerable to limestone quarrying, particularly in California. Other known threats include mineral extraction and ORVs.
Range Extent Comments
Known from the mountains of the northern Mojave Desert (San Bernardino Mountains and desert ranges) and the Great Basin in eastern California (San Bernardino, Inyo, and Mono counties), Nevada (Clark, Lincoln, Mineral, Nye, and White Pine counties), and western Utah (Beaver, Juab, Millard, and Tooele counties) (Hickman 1993, Homgren et al. 2005, Welsh et al. 2008). Also reported from Esmeralda and Elko counties in Nevada, but these records require confirmation. Known range extent is approximately 150,000 square km.
Occurrences Comments
Rangewide, at least 66 occurrences (likely an underestimate) are presumed extant. In Nevada, 33-38 occurrences are presumed extant (depending on separation distance) and one occurrence is considered extirpated (Morefield 2001). In California, 28 occurrences are presumed extant and an additional 13 are historical. In Utah, occurrences have not been mapped comprehesively, but Welsh et al. (2008) cite 16 specimens in the Brigham Young University herbarium (BYU), collected in four counties.
Threat Impact Comments
In California, threatened by mining (limestone quarries, mineral extraction) and ORVs (CNPS 2009). In Nevada, some occurrences may be threatened, but no known active impacts can be readily identified (Jim Morefield, personal communication 1999). Threats in Utah unknown.
Ecology & Habitat

Diagnostic Characteristics

Characterized by (1) a multi-layered basal rosette, (2) hoary-gray pubescence of leaves, stems, and inflorescences, and (3) arching glabrous siliques that are large compared to other species in the genus (Welsh et al. 2008).

Habitat

Tends to occur on calcareous substrates, such as limestone or dolomitic outcrops, gravels, and sediments; also occurs on quartzite rock and sands. Many sites are on rocky ridges and slopes. Often in pinyon-juniper woodlands; also occurs in sagebrush scrub, mountain mahogany, shadscale-galleta, and ephedra-matchweed communities. 875 - 2600 m.
Terrestrial Habitats
Forest/WoodlandWoodland - ConiferShrubland/chaparralDesertBare rock/talus/scree
Other Nations (1)
United StatesN3
ProvinceRankNative
CaliforniaS2Yes
NevadaS3Yes
UtahS2Yes
Plant Characteristics
Economic Value (Genus)No
Roadless Areas (7)
California (3)
AreaForestAcres
Andrews Mtn.Inyo National Forest9,912
Birch CreekInyo National Forest28,816
Soldier CanyonInyo National Forest40,589
Nevada (4)
AreaForestAcres
Boundary Peak (NV)Inyo National Forest21,851
Lovell Summit SouthHumboldt-Toiyabe National Forest28,455
PotosiHumboldt-Toiyabe National Forest5,145
QuinnHumboldt-Toiyabe National Forest62,459
References (14)
  1. Beatley, J.C. 1977. Threatened plant species of the Nevada Test Site, Ash Meadows, and central-southern Nevada. Prepared for U.S. Energy Research and Development Administration under Contract E(11-1)-2307.
  2. California Native Plant Society (CNPS). 2009. Inventory of Rare and Endangered Plants. California Native Plant Society. Sacramento, CA. Online. Available: http://www.cnps.org/inventory (accessed 2009).
  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. Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
  5. Holmgren, N.H., P.K. Holmgren, and A. Cronquist. 2005. Intermountain flora. Volume 2, part B. Subclass Dilleniidae. The New York Botanical Garden Press. 488 pages.
  6. Kartesz, J.T. 1988. A flora of Nevada. Ph.D. dissertation. Univ. of Nevada, Reno. 3 volumes. 1729 pp.
  7. 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.
  8. Morefield, J.D., editor. 2001. Nevada rare plant atlas [with rare plant fact sheets]. Available as a pdf file at: http://heritage.nv.gov/atlas/atlas.html. Compiled by the Nevada Natural Heritage Program, Carson City, for the U.S. Fish and Wildlife Service, Reno, Nevada.
  9. Morefield, Jim. Personal Communication. Botanist, Nevada Natural Heritage Program, Department of Conservation and Natural Resources, Carson City, Nevada.
  10. Nevada Natural Heritage Program. 1999. February 19-last update. List of sensitive plants. Online. Available: http://www.state.nv.us/nvnhp/sensplnt.htm. Accessed 1999, June 3.
  11. Rollins, R.C. 1981. Studies on Arabis (Cruciferae) of western North America. Systematic Botany 6(1): 55-64.
  12. Skinner, M.W., and B.M. Pavlik, eds. 1997 (1994). Inventory of rare and endangered vascular plants of California. 1997 Electronic Inventory Update of 1994 5th edition, California Native Plant Society, Special Publication No. 1, Sacramento.
  13. Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins (eds.) 1993. A Utah flora. 2nd edition. Brigham Young Univ., Provo, Utah. 986 pp.
  14. Welsh, S.L., N.D. Atwood, S. Goodrich and L.C. Higgins. (Eds.) 2008. A Utah Flora. 4th edition, revised. Brigham Young University, Provo, Utah, U.S.A. 1019 pp.