Astragalus atratus var. mensanus
Darwin mesa milkvetch, Darwin Mesa milk-vetch, Darwin Mesa milk-vetch
(c) Matt Berger, some rights reserved (CC BY), uploaded by Matt Berger · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.1
Astragalus atratus var. mensanus (Darwin mesa milkvetch) is a native California herb in the Fabaceae family, recognized by fiddle-shaped banner and twisted wing petals distinctive.
Darwin mesa milkvetch is a rare (CNPS 1B.1) California native perennial found in the northern and western Desert Mountains near Panamint Valley, Inyo County in open foothills with pinyon and sagebrush at elevations of 1,700 to 2,350 meters. Flowering from May to July, this plant produces dingy white and dull lilac flowers with a distinctive banner petal that appears fiddle-shaped and recurves almost 90 degrees. Growing with wiry, loose-matted stems 3 to 25 centimeters tall that are minutely strigose, it scrambles through scrub with a distinctive growth habit. Its compound leaves are 1.5 to 15 centimeters long, featuring 7 to 15 linear to slightly ovate leaflets 3 to 16 millimeters long with acute or shallowly notched tips. The fruit is a pendulous, linear-oblong pod 16 to 22 millimeters long, compressed side-to-side and covered in minute strigose hairs.
Identification and appearance
Key characters: 40 sympatric species; fiddle-shaped banner and twisted wing petals distinctive
Habitat and range
Habitat: Open foothills with pinyon, sagebrush
Elevation: 1700-2350 m
California counties: Inyo
Bloom period
Astragalus atratus var. mensanus blooms May-Jul.
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 atratus var. mensanus native to California?
Yes. Astragalus atratus var. mensanus is native to California (recorded as native).
When does Astragalus atratus var. mensanus bloom?
Astragalus atratus var. mensanus blooms May-Jul.
Where in California does Astragalus atratus var. mensanus grow?
Astragalus atratus var. mensanus occurs in Inyo, at elevations of 1700-2350 m.
What plant family does Astragalus atratus var. mensanus belong to?
Astragalus atratus var. mensanus is in the Fabaceae family, genus Astragalus.
Is Astragalus atratus var. mensanus rare or endangered?
Astragalus atratus var. mensanus 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.