Regularity: Regularly occurring
Global Range: 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.
Localities documented in Tropicos sources
United States (North America)
Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.
- Anonymous. 1986. List-Based Rec., Soil Conserv. Serv., U.S.D.A. Database of the U.S.D.A., Beltsville. http://www.tropicos.org/Reference/1103
- Williams, M. C. & R. C. Barneby. 1977. The Occurrence of Nitro-toxins in North America Astragalus (Fabaceae). Brittonia 29(3): 310–326. http://www.tropicos.org/Reference/94
- Barneby, R. C. 1964. Atlas of North American Astragalus. Mem. New York Bot. Gard. 13(1–2): 1–1188. http://www.tropicos.org/Reference/85
Catalog Number: US 1828580
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Card file verified by examination of alleged type specimen
Preparation: Pressed specimen
Collector(s): I. W. Clokey
Year Collected: 1937
Locality: Charleston Mountains, Harris Springs road., Clark, Nevada, United States, North America
Elevation (m): 2200 to 2200
- Isotype: Clokey, I. W. 1942. Madrono. 6: 215.
Comments: 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).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 6 - 80
Comments: 23 known element occurrences.
NatureServe Conservation Status
Rounded Global Status Rank: G2 - Imperiled
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.
Environmental Specificity: Moderate. Generalist or community with some key requirements scarce.
National NatureServe Conservation Status
Rounded National Status Rank: N2 - Imperiled
Global Short Term Trend: Relatively stable to decline of 30%
Comments: This species has disappeared from previously known sites that now have heavy recreation use. Also, 4% of the cited locations in the 'Adaptive Management Report for the Clark County, Nevada, Multiple Species Habitat Conservation Plan' (Sada et al. 2008) are expected to be directly impacted by the permit allowing conversion of wildnerness to development.
Degree of Threat: High
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.