Astragalus agnicidus
Humboldt county milkvetch, Humboldt County Milkvetch, Humboldt County milk-vetch, Humboldt County milk-vetch
(c) Aaron Liston, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.1
Astragalus agnicidus (Humboldt county milkvetch) is a native California herb in the Fabaceae family, recognized by dense reflexed flowers and triangular pods distinctive.
Humboldt county milkvetch is a rare (CNPS 1B.1) California native perennial found in southern Humboldt and Mendocino counties in open woodland soils at elevations of 300 to 750 meters. Flowering from May to August, this plant produces white flowers with a distinctive banner petal that curves back at a 45-degree angle in dense clusters of 10 to 40 blooms. Growing with erect stems 30 to 90 centimeters tall, it develops a coarse, leafy structure with sparse, fine, wavy hairs. Its compound leaves feature 13 to 27 leaflets, each 3 to 22 millimeters long, ranging from oblong to ovate in shape. The fruit develops as a reflexed, papery pod approximately 11 to 15 millimeters long with a slightly three-sided profile.
Identification and appearance
Key characters: 3 sympatric species; dense reflexed flowers and triangular pods distinctive
Habitat and range
Habitat: Open soil in woodland
Elevation: 300-750 m
California counties: Humboldt, Mendocino
Bloom period
Astragalus agnicidus blooms May-Aug.
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 agnicidus native to California?
Yes. Astragalus agnicidus is native to California (recorded as native).
When does Astragalus agnicidus bloom?
Astragalus agnicidus blooms May-Aug.
Where in California does Astragalus agnicidus grow?
Astragalus agnicidus occurs in Humboldt, Mendocino, at elevations of 300-750 m.
What plant family does Astragalus agnicidus belong to?
Astragalus agnicidus is in the Fabaceae family, genus Astragalus.
Is Astragalus agnicidus rare or endangered?
Astragalus agnicidus carries California Rare Plant Rank 1B.1, state rank S2.
Related species
Other California species in the same genus, family, or bioregion.
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.