Taxon Report

Astragalus magdalenae Greene var. peirsonii (Munz & McBurn.) Barneby

Peirson's milk-vetch

Print Report


Taxon Summary

Astragalus magdalenae var. peirsonii, commonly known as Peirson's milk-vetch, is a perennial herb in the Fabaceae that is found in California and elsewhere. It occurs within Desert dunes, growing at elevations from 60 to 225 meters. Astragalus magdalenae var. peirsonii is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

  Classification
Scientific Name:
 Astragalus magdalenae Greene var. peirsonii (Munz & McBurn.) Barneby
Common Name:
 Peirson's milk-vetch
Family: Fabaceae
Element Code: PDFAB0F532
USDA Plants Symbol: ASMAP
Synonyms/Other Names:

Ecology and Life History
Lifeform: perennial herb
Blooming Period: Dec-Apr Dec-Apr
Elevation: 60-225 (195-740)
General Habitats: Desert dunes
Microhabitat:
Microhabitat Details:

Conservation Status
CA Rare Plant Rank: 1B.2
Global Rank: G3G4T1
State Rank:
 S1
State List: CE
Fed List: FT
Other Status: SB_CalBG/RSABG
CRPR Changes:

Occurrence Data from the CNDDB
Total Occurrences: 3
Element Occurrence Ranks:
   Excellent (A) 0
   Good (B) 1
   Fair (C) 0
   Poor (D) 0
   None (X) 2
   Unknown (U) 0

Location
California Endemic:  False
California Counties and Islands: Name (Code)
Imperial (IMP), San Diego (SDG)(?)
Quads: Name (Quad Code)
Grays Well (3211468), Grays Well NE (3211467), Acolita (3311512), Amos (3311513), Borrego Mountain (3311622), Borrego Sink (3311623), Cactus (3211478), Clark Lake (3311633)(?), Clyde (3211488), East of Acolita (3311511), Glamis (3211581), Glamis NW (3211582), Glamis SE (3211571), Tortuga (3311523)

Threat List Data from the CNDDB

Threat List Total: 2
EOs with Threat Listed: Total EOs % of EOs
1 33 %
ORV activity 1 33%
Other 1 33%

Notes
One location in Anza-Borrego does not appear to be a naturally occurring population; DNA analysis pending. Plant not seen in SDG Co. in several decades. Threatened by vehicles in the Algodones Dunes. Threatened elsewhere by vehicles, grazing and trampling, foot traffic, non-native plants, development, and hydrological alterations. See Bulletin of the Southern California Academy of Sciences 31:67 (1932) for original description, and Memoirs of the New York Botanical Garden 13:928 (1964) for taxonomic treatment.
Threats:
Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 5 February 2025].