Taxon Report

Astragalus preussii Gray var. laxiflorus Gray

Lancaster milk-vetch

Print Report

Taxon Summary

Astragalus preussii var. laxiflorus, commonly known as Lancaster milk-vetch, is a perennial herb in the Fabaceae that is found in California and elsewhere. It occurs within Chenopod scrub, growing at elevations from 700 to 700 meters. Astragalus preussii var. laxiflorus is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Astragalus preussii Gray var. laxiflorus Gray
Common Name:	Lancaster milk-vetch
Family:	Fabaceae
Element Code:	PDFAB0F721
USDA Plants Symbol:	ASPRL2
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial herb
Blooming Period: Mar-May	Mar-May
Elevation:	700-700 (2295-2295)
General Habitats:	Chenopod scrub
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G4T2
State Rank:	S1
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	5
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	2
Unknown (U)	3

Location


California Endemic: False
California Counties and Islands: Name (Code)
Kern (KRN), Los Angeles (LAX), Riverside (RIV)
Quads: Name (Quad Code)
Indio (3311662), La Quinta (3311663), Lancaster East (3411861), Lancaster West (3411862)?*, Martinez Mtn. (3311653), Redman (3411778)

Threat List Data from the CNDDB


Threat List Total:	1
EOs with Threat Listed:	Total EOs	% of EOs
	1	20 %
Development	1	20%

Notes



Known in CA only from near Lancaster and Edwards AFB, where extremely rare; only reported once in recent years. Field work needed. See Proceedings of the American Academy of Arts and Sciences 13:369 (1878) for original description, and Memoirs of the New York Botanical Garden 13:576 (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 18 November 2025].