Astragalus didymocarpus var. obispoensis
San luis obispo milkvetch
(c) Mark Pollock, some rights reserved (CC BY), uploaded by Mark Pollock · licence
Family: Fabaceae · Type: Herb · Native
Astragalus didymocarpus var. obispoensis (San luis obispo milkvetch) is a native California herb in the Fabaceae family, recognized by crescent-shaped keel with acute tip diagnostic.
San luis obispo milkvetch is a California native annual found in southern Coastal Range and southwestern California in grassy hills and chaparral openings at elevations of 400 to 1,150 meters. Flowering from March to May, this plant produces small whitish flowers in clusters of 5 to 30 blossoms with delicate crescent-shaped keel petals. Growing with ascending stems 2.5 to 25 centimeters tall, the plant has a distinctively gray-hairy appearance. Its herbage is covered in soft grayish hairs, with leaves composed of multiple leaflets that blend into the surrounding grassland. The flower's banner reaches 6.2 to 8.6 millimeters long, with calyx lobes 1 to 2.5 millimeters in length.
Identification and appearance
Key characters: 39 sympatric species; crescent-shaped keel with acute tip diagnostic
Habitat and range
Habitat: Grassy hills, openings in chaparral
Elevation: 400-1150 m
California counties: Santa Barbara, Riverside, Imperial, Los Angeles, San Diego, San Luis Obispo, Ventura
Outside California: Baja California
Bloom period
Astragalus didymocarpus var. obispoensis blooms Mar-May.
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 didymocarpus var. obispoensis native to California?
Yes. Astragalus didymocarpus var. obispoensis is native to California (recorded as native).
When does Astragalus didymocarpus var. obispoensis bloom?
Astragalus didymocarpus var. obispoensis blooms Mar-May.
Where in California does Astragalus didymocarpus var. obispoensis grow?
Astragalus didymocarpus var. obispoensis occurs in Santa Barbara, Riverside, Imperial, Los Angeles, San Diego, San Luis Obispo, Ventura, at elevations of 400-1150 m.
What plant family does Astragalus didymocarpus var. obispoensis belong to?
Astragalus didymocarpus var. obispoensis is in the Fabaceae family, genus Astragalus.
What habitat does Astragalus didymocarpus var. obispoensis grow in?
Astragalus didymocarpus var. obispoensis grows in Grassy hills, openings in chaparral.
Related species
Other California species in the same genus, family, or bioregion.
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.