Astragalus preussii var. laxiflorus
Lancaster milkvetch
Photo: parent species Astragalus preussii · (c) Darrin Gobble, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.1
Astragalus preussii var. laxiflorus (Lancaster milkvetch) is a native California herb in the Fabaceae family, recognized by alkaline habitat and robust size.
Lancaster milkvetch is a rare (CNPS 1B.1) California native perennial found in southwestern Mojave Desert and western Colorado Desert, specifically in the Coachella Valley, on alkaline flats at elevations of 700 meters. Flowering from March to May, this plant produces small white to cream-colored flowers in loose clusters. Growing with slender stems 10 to 30 centimeters tall, it forms a delicate, spreading herbaceous habit. Its pinnately compound leaves have 11 to 21 narrow, elongated leaflets that are light green and approximately 5 to 15 millimeters long. The fruit is a small, inflated pod characteristic of milkvetches, adapted to its arid, alkaline habitat.
Identification and appearance
Key characters: 19 sympatric species; key features are alkaline habitat and robust size
Habitat and range
Habitat: Alkaline flats
Elevation: 700 m
California counties: Los Angeles, Kern, Riverside
Outside California: southern Nevada, southwestern Utah, western Arizona
Bloom period
Astragalus preussii var. laxiflorus blooms Mar-May.
Conservation status
CNPS 1B.1
How to tell it apart
vs Vicia: Astragalus has racemes of flowers; vetches (Vicia) have tendrils at leaf tips and climbing or sprawling habit.; vs Oxytropis: Astragalus keel tip is rounded to slightly pointed; Oxytropis keel has a pronounced pointed beak.; vs Cleomella: Astragalus has pea-shaped flowers; Cleomella has 4-petaled cruciform flowers with long stamens.; vs Lupinus: Astragalus has pinnate compound leaves; lupines have palmate leaves (leaflets radiating from one point).; vs Dalea: Astragalus has typical pea flowers; Dalea has tiny flowers with petals attached to the stamen tube.
Frequently asked questions
Is Astragalus preussii var. laxiflorus native to California?
Yes. Astragalus preussii var. laxiflorus is native to California (recorded as native).
When does Astragalus preussii var. laxiflorus bloom?
Astragalus preussii var. laxiflorus blooms Mar-May.
Where in California does Astragalus preussii var. laxiflorus grow?
Astragalus preussii var. laxiflorus occurs in Los Angeles, Kern, Riverside, at elevations of 700 m.
What plant family does Astragalus preussii var. laxiflorus belong to?
Astragalus preussii var. laxiflorus is in the Fabaceae family, genus Astragalus.
Is Astragalus preussii var. laxiflorus rare or endangered?
Astragalus preussii var. laxiflorus carries California Rare Plant Rank 1B.1, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
- Astragalus preussii var. preussii — Preuss' milkvetch
- Astragalus pseudiodanthus — Tonopah milkvetch
- Astragalus pulsiferae — Ames' milkvetch
- Astragalus pulsiferae var. coronensis — Modoc plateau milkvetch
- Astragalus pulsiferae var. pulsiferae — Pulsifer's milkvetch
- Astragalus pulsiferae var. suksdorfii — Suksdorf's milkvetch
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.