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Astragalus johannis-howellii

Barneby

Long Valley Milkvetch

G2Imperiled Found in 8 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
HighThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.144196
Element CodePDFAB0F4H0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderFabales
FamilyFabaceae
GenusAstragalus
Other Common Names
Long Valley 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 Method Rank calculation - Biotics v2
Review Date2024-04-11
Change Date1990-09-05
Edition Date2024-04-11
Edition AuthorsBittman, R.L., rev. D. Gries (1999), rev. R. Bittman (2013), rev. Johnson, J. (2024)
Threat ImpactHigh
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences6 - 20
Rank Reasons
Astragalus johannis-howellii is a perennial herb of the western United States that occurs only in the Great Basin ecoregion in Nevada and California. Most populations occur on Bureau of Land Management and National Forest Service lands. The species is threatened by grazing, vehicles, geothermal developments, mining, and invasive species.
Range Extent Comments
Astragalus johannis-howellii occurs in the western United States where it is limited to the Great Basin ecoregion of western Nevada and eastern California. Range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1993 and 2024 (CNDDB 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, it is estimated that there are fifteen occurrences range-wide, eight in California, six in Nevada, and one shared between both states (CNDDB 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024). When historical collections are included, there may be up to eleven additional occurrences in California.
Threat Impact Comments
Major threats to Astragalus johannis-howellii include invasive plants, feral horses, livestock grazing, off-highway vehicle use, mining and geothermal energy exploration, and road maintenance (CNDDB 2024, Nachlinger 1999, NatureServe 2024, SEINet 2024). Many of the occurrences are within grazing allotments for cattle or sheep. The plants appear to be unpalatable to livestock, but trampling, weeds spread by animals, and altered fire regime are concerns. Mining and exploratory drilling have impacted some populations in Nevada, and exploration for lithium may impact more areas in the eastern Sierra region. Fire in this habitat is generally low severity due to low fuel loads, but invasive species and climate change may increase the risk and severity of fires. All populations face threats from invasive plant species, with those close to human developments having larger and more diverse weed populations. Feral horses are present throughout the range of Astragalus johannis-howellii, and their numbers are increasing (INF 2024). Some occurrences are near roads including Highway 395, and smaller dirt roads and trails. Recreational activities including off-highway vehicle use is increasing in this region. One occurrence is adjacent to a landfill that has impacted approximately 44 hectares of habitat, and any expansion will impact additional habitat.
Ecology & Habitat

Habitat

Astragalus johannis-howellii grows in low sagebrush flats with sandy loam soil. It is occasionally found in swales in the vicinity of former or present hot springs activity (Skinner 1997).
Terrestrial Habitats
Shrubland/chaparral
Other Nations (1)
United StatesN2
ProvinceRankNative
CaliforniaS1Yes
NevadaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentSmall (1-10%)Extreme or 71-100% pop. declineModerate (short-term)
1.2 - Commercial & industrial areasSmall (1-10%)Extreme or 71-100% pop. declineModerate (short-term)
2 - Agriculture & aquacultureLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
2.3 - Livestock farming & ranchingLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
3 - Energy production & miningLarge - smallModerate or 11-30% pop. declineModerate (short-term)
3.2 - Mining & quarryingLarge - smallModerate or 11-30% pop. declineModerate (short-term)
4 - Transportation & service corridorsSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
4.1 - Roads & railroadsSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
6 - Human intrusions & disturbanceSmall (1-10%)Slight or 1-10% pop. declineHigh (continuing)
6.1 - Recreational activitiesSmall (1-10%)Slight or 1-10% pop. declineHigh (continuing)
7 - Natural system modificationsPervasive (71-100%)Slight or 1-10% pop. declineModerate (short-term)
7.1 - Fire & fire suppressionPervasive (71-100%)Slight or 1-10% pop. declineModerate (short-term)
8 - Invasive & other problematic species, genes & diseasesPervasive (71-100%)Moderate or 11-30% pop. declineHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesPervasive (71-100%)Moderate or 11-30% pop. declineHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)Yes
Roadless Areas (8)
California (3)
AreaForestAcres
Excelsior (CA)Inyo National Forest45,607
Glass MountainInyo National Forest52,867
WattersonInyo National Forest6,922
Nevada (5)
AreaForestAcres
Chineese Camp (NV)Humboldt-Toiyabe National Forest15,207
Excelsior Mtns.Humboldt-Toiyabe National Forest69,071
Long ValleyHumboldt-Toiyabe National Forest50,472
Mt. HicksHumboldt-Toiyabe National Forest15,698
Pine Grove SouthHumboldt-Toiyabe National Forest88,945
References (15)
  1. California Department of Fish and Game. 2000. Natural Diversity Database (RareFind 2), Version 2.1.2, January 25, 2000. Downloaded in 2003.
  2. California Native Plant Society (CNPS). 2001. Inventory of Rare and Endangered Plants of California (sixth edition). Rare Plant Scientific Advisory Committee, David P. Tibor, Convening Editor. California Native Plant Society. Sacramento, CA. x + 388pp.
  3. California Natural Diversity Database (CNDDB). 2013. RareFind Version 4. California Department of Fish and Game, Sacramento.
  4. California Natural Diversity Database (CNDDB). 2024. RareFind Version 5.3.0. California Department of Fish and Game, Sacramento.
  5. Flora of North America Editorial Committee (FNA). 2023. Flora of North America north of Mexico. Vol. 11. Magnoliophyta: Fabaceae, parts 1+2. Oxford Univ. Press, New York. xxvii + 1108 pp.
  6. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  7. Inyo National Forest. 2024. Wild Horse Management (webpage) Available here: https://www.fs.usda.gov/detail/inyo/landmanagement/resourcemanagement/?cid=fseprd1145518. Accessed 04/25/2024.
  8. 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.
  9. 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]
  10. Morefield, Jim. Personal Communication. Botanist, Nevada Natural Heritage Program, Department of Conservation and Natural Resources, Carson City, Nevada.
  11. Nachlinger, J. 1999. A review of Astragalus in Nevada and its conservation status. Northern Nevada Native Plant Society Newsletter 25(3): 3-4.
  12. NatureServe. 2024. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  13. 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.
  14. 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.
  15. Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).