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Home/Species/ Tahoe Yellowcress

Rorippa subumbellata

Rollins

Tahoe Yellowcress

G1Critically Imperiled Found in 3 roadless areas NatureServe Explorer →
G1Critically ImperiledGlobal Rank
Very high - highThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.153949
Element CodePDBRA270M0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusRorippa
Other Common Names
Tahoe Yellow Cress (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 MethodLegacy Rank calculation - Excel v3.1x
Review Date2016-05-26
Change Date2001-05-23
Edition Date2016-05-26
Edition AuthorsJ. Morefield (NVHP, 2004); rev. R. Bittman 5/2005; rev. L. Morse (2006), rev. R. Bittman 2006, rev. A. Tomaino (2011), rev. A. Treher and Bittman (2016)
Threat ImpactVery high - high
Range Extent250-1000 square km (about 100-400 square miles)
Number of Occurrences21 - 80
Rank Reasons
Tahoe yellow-cress is known from approximately 44-63 occurrences. There are many historical occurrences. The species occupies a very narrow habitat band within the shore zone of Lake Tahoe, California and Nevada. The habitat experiences heavy recreational use at most sites, and is regularly subject to major contractions caused by maintenance of artificially high water levels in Lake Tahoe, with resulting further concentration of beach impacts in the habitat remaining exposed. Only the two largest occurrences (and about 20-35% of the total sub-EOs) remain active during prolonged periods of high water. Portions of the lakeside habitat have been developed for casinos (on the Nevada side of the lake) and for other tourism-related facilities, and many other portions are in heavily visited parklands.
Range Extent Comments
Restricted to the shore zone of Lake Tahoe, California and Nevada, which surrounds about 500-sq km of water area.
Occurrences Comments
Known from approximately sixty-two occurrences but the number maybe less depending on separation distance or year, as plants are dependent on water levels.
Threat Impact Comments
The greatest threat to the species is recreational activities on public beaches and adjacent habitats. Other threats include artificially prolonged high-water levels, and shorezone development and maintenance activities on private lands (Morefield 2001; USFWS 2010). This species is legally protected and closely monitored in both Nevada and California, but subject to intense impacts in this high-tourism area, especially from beach use and maintenance, shore-zone development, and artificially prolonged high-water levels in Lake Tahoe which further contract and concentrate impacts on beach areas remaining exposed. Some occurrences have been fenced or otherwise protected from beach use, but long-term effectiveness depends on adequate resources for maintenance. Water levels in Lake Tahoe have peaked at or near maximum over half of the past 55 years. The species recolonizes remaining suitable habitat fairly readily when lake levels drop, if impacts have not been too severe.
Ecology & Habitat

Description

Perennial herb from deeply buried rhizomes, overall color dark to purplish green (sometimes yellowish); stems generally prostrate, 5-20 cm long; leaves mainly on stems (not basal), somewhat succulent, pinnately lobed; flowers 2.5-4 mm long, crowded near tips of stems, sepals 4, purplish-green, hairless and persistent in fruit, petals 4, yellow, stamens 6; seed pods shiny, 3-6 mm long, > 1.5 mm wide, hairless, styles 1-1.5 mm long, hairless, stigmas not expanded. Distinguished from Rorippa columbiae by its glabrous sepals, fruits, and styles, styles 1-1.5 mm long, and stigmas not expanded. Distinguished from R. curvisiliqua by perennial rhizomatous habit, lack of basal leaf rosette, flowers 2.5-4 mm long, sepals persistent in fruit, fruit 3-6 mm long, > 1.5 mm wide.

Habitat

Coarse sand and sandy soils, often among cobbles or boulders, of active beaches, stream inlets, beach dunes, and backshore depressions, generally within a few feet of the local water table, in the shore zone of Lake Tahoe (Morefield 2001).
Terrestrial Habitats
Sand/dune
Palustrine Habitats
HERBACEOUS WETLANDRiparian
Other Nations (1)
United StatesN1
ProvinceRankNative
NevadaS1Yes
CaliforniaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentLarge (31-70%)Serious - moderateHigh - moderate
1.3 - Tourism & recreation areasLarge (31-70%)Serious - moderateHigh - moderate
6 - Human intrusions & disturbanceLarge (31-70%)Serious - moderateHigh (continuing)
6.1 - Recreational activitiesLarge (31-70%)Serious - moderateHigh (continuing)
7 - Natural system modificationsLarge (31-70%)Serious - moderateHigh - moderate
7.2 - Dams & water management/useLarge (31-70%)Serious - moderateHigh - moderate

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Plant Characteristics
Economic Value (Genus)No
Roadless Areas (3)
California (2)
AreaForestAcres
DardanellesEldorado National Forest8,110
PyramidEldorado National Forest24,347
Nevada (1)
AreaForestAcres
Jobs Peak (NV)Humboldt-Toiyabe National Forest1,342
References (16)
  1. DeWoody, J. and V.D. Hipkins. 2004. Draft Final Report for the Expanded Evaluation of Genetic Diversity in Tahoe Yellow Cress (Rorippa subumbellata). Service Agreement 14320-2-H401. National Forest Genetic Electrophoresis Laboratory, USDA Forest Service, Camino, CA.
  2. 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.
  3. Kartesz, John T., Director, Biota of North America Program, Chapel Hill, North Carolina; formerly at Univ. Nevada, Reno, and at North Carolina Botanical Garden, Chapel Hill.
  4. 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.
  5. Knapp, C.M. 1979. Sensitive plant investigation. II. Rorippa subumbellata Roll. its status on historical and potentially new sites. U.S. Forest Service, Lake Tahoe Basin Management Unit. 7 pp.
  6. 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.
  7. Morefield, Jim. Personal Communication. Botanist, Nevada Natural Heritage Program, Department of Conservation and Natural Resources, Carson City, Nevada.
  8. Morse, Larry E. Personal Communication. North American Botanist, NatureServe, Arlington, VA. Formerly Chief Botanist, The Nature Conservancy, Arlington, VA.
  9. Pavlik, B., D. Murphy, and Tahoe Yellow Cress Technical Advisory Group. 2002. Conservation Strategy for Tahoe Yellow Cress (<i>Rorippa subumbellata</i>). Tahoe Regional Planning Agency, Zephyr Cove, Nevada. 106 pp., plus appendices. [http://www.fws.gov/nevada/es/documents/esa/Final_TYC_CS.pdf]
  10. Rollins, R.C. 1941. Some new or noteworthy North American crucifers. Contributions from the Dudley Herbarium 3: 174-184.
  11. Stanton, A. E. and B. M. Pavlik. 2010. Implementation of the Conservation Strategy for Tahoe Yellow Cress (<i>Rorippa subumbellata</i>). 2009 Annual Report. BMP Ecosciences, San Francisco, CA, prepared for Tahoe Yellow Cress Adaptive Management Working Group, Executive Committee, and the USFS Lake Tahoe Basin Management Unit, March 2010. Online. Available: http://heritage.nv.gov/reports/rosu_annrep_2009.pdf (Aaccessed 2011).
  12. U.S. Fish and Wildlife Service (USFWS). 2003. Draft Tahoe Yellow Cress (<i>Rorippa subumbellata</i>) 2003 Annual Survey Report, March 2004. U. S. Fish and Wildlife Service, Reno, Nevada.
  13. U.S. Fish and Wildlife Service (USFWS). 2004. Species assessment and listing priority assignment form. <i>Rorippa subumbellata.</i> 17 pp.
  14. U.S. Fish and Wildlife Service (USFWS). 2010. Species assessment and listing priority assignment form. <i>Rorippa subumbellata.</i> 21 pp. Online. Available: http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=Q1LW (Accessed 2011).
  15. U.S. Fish and Wildlife Service (USFWS). 2015. 12-Month Findings on Petitions To List 19 Species as Endangered or Threatened Species<i>. </i>Federal Register 80(195): 60834-60850.
  16. U.S. Fish and Wildlife Service (USFWS). 27 December 2004. Endangered and threatened wildlife and plants; 12-month findings on resubmitted petitions to list the Southern Idaho Ground Squirrel, Sand Dune Lizard, and Tahoe Yellow Cress. Federal Register 69(247):77167-77173.