Astragalus whitneyi var. siskiyouensis
Siskiyou milkvetch
(c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda · licence
Family: Fabaceae · Type: Herb · Native
Astragalus whitneyi var. siskiyouensis (Siskiyou milkvetch) is a native California herb in the Fabaceae family, recognized by appressed hairs and serpentine habitat help distinguish from other varieties.
Siskiyou milkvetch is a California native perennial found in the Klamath Ranges, northern Coast Ranges, Cascade Ranges, and Modoc Plateau in open, gravelly or rocky areas and pine/fir forests, often on serpentine at elevations of 750 to 2,750 meters. Flowering from June to August, this plant produces cream-colored flowers in clusters of 4 to 16 blooms, with banner petals 9.5 to 13.5 millimeters long. Growing with green or grayish stems and herbage covered in appressed hairs, it forms a compact perennial with leaves 3 to 9 centimeters long and visible spaces between leaflets. Its leaves are composed of multiple leaflets, giving the plant a delicate, open structure typical of milkvetches. The fruit is a pod 1.5 to 6 centimeters long with a short 3 to 6 millimeter stalk-like base, which is entirely glabrous.
Identification and appearance
Key characters: 34 sympatric species; appressed hairs and serpentine habitat help distinguish from other varieties
Habitat and range
Habitat: Open, gravelly or rocky areas, pine/fir forest, often on serpentine
Elevation: 750-2750 m
California counties: Siskiyou, Modoc, Lassen, Tehama, Trinity, Mendocino, Shasta
Outside California: southern Oregon
Bloom period
Astragalus whitneyi var. siskiyouensis blooms Jun-Aug.
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 whitneyi var. siskiyouensis native to California?
Yes. Astragalus whitneyi var. siskiyouensis is native to California (recorded as native).
When does Astragalus whitneyi var. siskiyouensis bloom?
Astragalus whitneyi var. siskiyouensis blooms Jun-Aug.
Where in California does Astragalus whitneyi var. siskiyouensis grow?
Astragalus whitneyi var. siskiyouensis occurs in Siskiyou, Modoc, Lassen, Tehama, Trinity, Mendocino, Shasta, at elevations of 750-2750 m.
What plant family does Astragalus whitneyi var. siskiyouensis belong to?
Astragalus whitneyi var. siskiyouensis is in the Fabaceae family, genus Astragalus.
What habitat does Astragalus whitneyi var. siskiyouensis grow in?
Astragalus whitneyi var. siskiyouensis grows in Open, gravelly or rocky areas, pine/fir forest, often on serpentine.
Related species
Other California species in the same genus, family, or bioregion.
- Astragalus whitneyi var. whitneyi — Balloonpod milkvetch
- Astragalus accidens var. hendersonii — Henderson's milkvetch
- Astragalus acutirostris — Beaked rattle weed
- Astragalus agnicidus — Humboldt county milkvetch
- Astragalus agrestis — Field milkvetch
- Astragalus albens — Cushenbury milkvetch
- Bituminaria bituminosa — Arabian pea
- Bituminaria sp.
- Caesalpinia gilliesii — Bird-of-paradise
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
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.