Cirsium clokeyi

Blake

Clokey's Thistle

G1Critically Imperiled Found in 3 roadless areas NatureServe Explorer →
G1Critically ImperiledGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.140268
Element CodePDAST2E0R0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusCirsium
Synonyms
Cirsium eatonii var. clokeyi(S.F. Blake) D.J. Keil
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
Siniscalchi et al. (2023) treat this taxon as Cirsium clokeyi. It was recognized as C. eatonii var. clokeyi by FNA (vol. 19, 2006). Siniscalchi et al. (2023) recognize the following twelve distinct species in the Cirsium eatonii complex: C. clokeyi, C. culebraense, C. eatonii, C. funkiae, C. harrisonii, C. hesperium, C. murdockii, C. peckii, C. scopulorum, C. tukuhnikivatzicum, C. tweedyi, C. viperinum.
Conservation Status
Rank MethodLegacy Rank calculation - Biotics v1
Review Date2019-06-11
Change Date2019-06-11
Edition Date2013-05-02
Edition AuthorsOliver, L. (2013), rev. A. Tomaino (2019)
Threat ImpactUnknown
Range Extent<100 square km (less than about 40 square miles)
Number of Occurrences6 - 20
Rank Reasons
A Nevada endemic with about 12 known occurrences, all at higher elevations, primarily in the core area of the Spring Mountains. Threats include habitat alteration, climate change, recreation and exotic species.
Range Extent Comments
One mountain range in Clark County, Nevada within approximately 58 sq km (NatureServe data 2013).
Occurrences Comments
A 2014 analysis of available spatial data indicates twelve estimated occurrences separated by 1 km or more (J. Morefield, pers. comm., 2019).
Threat Impact Comments
An 'Adaptive Management Report for Clark County, Nevada, Multiple Species Habitat Conservation Plan (MSHCP)' was written in 2008 for all of Clark County, Nevada in response to an Incidental Take Permit held by Clark County, Nevada Department of Transportation and several cities. The Incidental Take Permit allows up to 145,000 acres of habitat loss to take place over 30 years beginning in January 2001 (Sada et al. 2008). Cirsium clokeyi is endemic to Clark County, Nevada, Spring Mountains and is considered in the MSHCP. It is estimated that approximately 13% of the considered sites of C. clokeyi in the Plan will be lost due to direct human impacts from the Permit (Sada et al. 2008). Sada et al. 2008 note the following major threats to the communities in which Cirsium clokeyi is found: Climate Change, Recreation, and change in fire regime (i.e. mega fires). Sada et al. (2008) notes Climate Change is a major threat to the Spring Mountains because are completely surrounded by desert which has isolated the Alpine ecosystem where C. clokeyi occurs. C. clokeyi occurs in other habitat types in the Spring Mountains including Mixed-conifer and Bristlecone Pine (where cold temperature is a major system driver) ecosystems (Sada et al. 2008). Also, it occurs in alpine habitat adjacent to hiking trails (Morefield 2001). Finally, exotic species are a threat.
Ecology & Habitat

Habitat

Open, moist gravelly slopes and ridges at 2280-3400 m elevation in openings of mixed conifer and bristlecone pine forests and on disturbed ground such as avalanche paths. Also occurs in seep areas, drainage bottoms, and snow depressions over carbonate soils (Morefield 2001).
Terrestrial Habitats
Forest/WoodlandForest - Conifer
Other Nations (1)
United StatesN1
ProvinceRankNative
NevadaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentLarge - restrictedSerious - moderateHigh - moderate
6 - Human intrusions & disturbanceSmall (1-10%)Slight or 1-10% pop. declineUnknown
7 - Natural system modificationsLarge (31-70%)Moderate - slightModerate - low
8 - Invasive & other problematic species, genes & diseasesRestricted (11-30%)Serious - slightUnknown
10 - Geological eventsRestricted (11-30%)Serious - slightUnknown
10.3 - Avalanches/landslidesRestricted (11-30%)Serious - slightUnknown
11 - Climate change & severe weatherPervasive (71-100%)Serious - slightModerate - low

Plant Characteristics
Economic Value (Genus)No
Roadless Areas (3)
Nevada (3)
AreaForestAcres
Angel Peak NorthHumboldt-Toiyabe National Forest12,577
Charleston - CarpenterHumboldt-Toiyabe National Forest17,828
Charleston - Macks CynHumboldt-Toiyabe National Forest11,378
References (6)
  1. Flora of North America Editorial Committee (FNA). 2006a. Flora of North America north of Mexico. Vol. 19. Magnoliophyta: Asteridae, part 6: Asteraceae, part 1. Oxford University Press, New York. xxiv + 579 pp.
  2. Kartesz, J.T. 1988. A flora of Nevada. Ph.D. dissertation. Univ. of Nevada, Reno. 3 volumes. 1729 pp.
  3. 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.
  4. Morefield, J. D., editor. 2001. Nevada rare plant atlas [with rare plant fact sheets]. Compiled by the Nevada Natural Heritage Program, Carson City, for the U.S. Fish and Wildlife Service. [http://heritage.nv.gov/atlas/atlas.html]
  5. Sada, D., M. Stone, D. Mouat, J. Lancaster, P. Lee, S. MacCabe, L. Bice, M. Hamilton and S. Wainscott. 2008a. Adaptive Management Report for the Clark County, Nevada, Multiple Species Habitat Conservation Plan. Clark County, Nevada. Department of Air Quality and Environmental Management. Desert Conservation Program. Las Vegas, Nevada. Online. Available: https://digitalscholarship.unlv.edu/cgi/viewcontent.cgi?article=1002&context=conserv_pubs.
  6. Siniscalchi, C.M., J.R. Ackerfield, and R.A. Folk. 2023. Diversification and biogeography of North American thistles (<i>Cirsium</i>: Carduoideae: Compositae): Drivers of a rapid continent-wide radiation. International Journal of Plant Sciences 184: 322-341.