Roadless Areas
Home/Species/ Clokey's Milkvetch

Astragalus aequalis

Clokey

Clokey's Milkvetch

G2Imperiled Found in 5 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
HighThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.144689
Element CodePDFAB0F070
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderFabales
FamilyFabaceae
GenusAstragalus
Other Common Names
Clokey's milkvetch (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 Date2013-05-06
Change Date1990-09-05
Edition Date2013-05-06
Edition AuthorsRoth, E., and S. Cochrane, rev. J. Nachlinger (1997), rev. L. Oliver (2013)
Threat ImpactHigh
Range Extent100-250 square km (about 40-100 square miles)
Number of Occurrences6 - 80
Rank Reasons
There are currently 23 known occurrences, all in Clark County, Nevada. Restricted to limestone bedrock habitats in the Spring Mountains. This species has disappeared from previously known sites that now have heavy recreation use. Extant occurrences are also threatened by increased development and recreational use of the area. Additional threats are mountain home development and 'rural sprawl', mega-fires, climate change, non-native species, road construction and maintenance, and wild horse and burro trampling.
Range Extent Comments
Clark county, Nevada. East and north slopes of the Spring Mountains. One population on the west side of Charleston Mountain. Morefield (2001) noted the maximum range dimension as 17mi.
Occurrences Comments
23 known element occurrences.
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 habita loss to take place over 30 years beginning in January 2001 (Sada et al. 2008). Astragalus aequalis is endemic to Clark County, Nevada, Spring Mountains and is considered in the MSHCP. It is estimated that approximately 4% of the considered sites of A. aequalis 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 A. aequalis is found: incidence of mega-fires, non-native species, development, recreation, and climate change.
Ecology & Habitat

Habitat

Calcareous gravelly flats, hillsides, and open ridges at 1800-2560 m elevation. Often sheltering under sagebrush (Artemisia tridentata) or gambel oak (Quercus gambelii). Other common associates include Utah juniper (Juniperus osteosperma) and curl-leaf mountain mahogany (Cercocarpus ledifolius var. intermontanus).
Terrestrial Habitats
Shrubland/chaparral
Other Nations (1)
United StatesN2
ProvinceRankNative
NevadaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentLarge (31-70%)Moderate - slightHigh (continuing)
6 - Human intrusions & disturbanceRestricted - smallModerate - slightHigh (continuing)
7 - Natural system modificationsLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
11 - Climate change & severe weatherLarge (31-70%)Moderate - slightHigh (continuing)

—

Plant Characteristics
Economic Value (Genus)Yes
Roadless Areas (5)
Nevada (5)
AreaForestAcres
Angel Peak NorthHumboldt-Toiyabe National Forest12,577
Angel Peak SouthHumboldt-Toiyabe National Forest6,540
Charleston - ClarkHumboldt-Toiyabe National Forest4,674
Charleston - Macks CynHumboldt-Toiyabe National Forest11,378
Charleston - McfarlandHumboldt-Toiyabe National Forest2,465
References (6)
  1. Barneby, R.C. 1964. Atlas of North American Astragalus. 2 Vols. New York Botanical Garden, Bronx, New York. 1188 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. Mozingo, H.N., and M. Williams. 1980. The threatened and endangered plants of Nevada. U.S. Fish and Wildlife Service and Bureau of Land Management, Portland, OR. 268 pp.
  6. 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.