Astragalus magdalenae var. peirsonii
Peirson's milkvetch
Photo by Chez Brungraber
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.2 · Threatened
Astragalus magdalenae var. peirsonii (Peirson's milkvetch) is a native California herb in the Fabaceae family, recognized by dune habitat and few narrow leaflets.
Peirson's milkvetch is a rare (CNPS 1B.2) California native perennial found in the Algodones Dunes in southern California's desert regions at elevations of 50 to 250 meters. Flowering from December to April, this plant produces pink-purple flowers with white-tipped petals in clusters of 5 to 20 blooms. Growing with ascending or erect silvery-canescent stems 20 to 90 centimeters tall, it develops a distinctive plant structure with loosely spaced leaflets. Its leaves feature 9 to 13 narrow, oblong leaflets each 2 to 8 millimeters long, creating a delicate silvery-gray foliage. The fruit is a distinctive bladdery, papery pod 20 to 35 millimeters long, spreading outward with a half-ovate to nearly spherical shape.
Identification and appearance
Key characters: 19 sympatric species; distinguished by dune habitat and few narrow leaflets
Habitat and range
Habitat: Sand dunes
Elevation: 50-250 m
California counties: San Diego, Imperial, Riverside
Outside California: northwestern Mexico
Bloom period
Astragalus magdalenae var. peirsonii blooms Dec-Apr.
Conservation status
CNPS 1B.2 · Threatened
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 magdalenae var. peirsonii native to California?
Yes. Astragalus magdalenae var. peirsonii is native to California (recorded as native).
When does Astragalus magdalenae var. peirsonii bloom?
Astragalus magdalenae var. peirsonii blooms Dec-Apr.
Where in California does Astragalus magdalenae var. peirsonii grow?
Astragalus magdalenae var. peirsonii occurs in San Diego, Imperial, Riverside, at elevations of 50-250 m.
What plant family does Astragalus magdalenae var. peirsonii belong to?
Astragalus magdalenae var. peirsonii is in the Fabaceae family, genus Astragalus.
Is Astragalus magdalenae var. peirsonii rare or endangered?
Astragalus magdalenae var. peirsonii carries California Rare Plant Rank 1B.2, state rank S1.
Related species
Other California species in the same genus, family, or bioregion.
- Astragalus malacus — Shaggy milkvetch
- Astragalus miguelensis — San miguel island milkvetch
- Astragalus minthorniae var. villosus — Minthorn's milkvetch
- Astragalus mohavensis — Mohave locoweed
- Astragalus mohavensis var. hemigyrus — Curved-pod milkvetch
- Astragalus mohavensis var. mohavensis — Mojave 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.