Astragalus iodanthus var. diaphanoides
Snake milkvetch, snake milk-vetch, snake milk-vetch
(c) Jim Morefield, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 4.3
Astragalus iodanthus var. diaphanoides (Snake milkvetch) is a native California herb in the Fabaceae family, recognized by no sympatric species.
Snake milkvetch is a California native perennial ranked 4.3 by CNPS, found in southeastern Modoc Plateau in Lassen County on dry, barren areas with sandy to volcanic ash soils at elevations of 1,200 to 1,400 meters. Flowering from April to June, this plant produces delicate white to pale purple flowers in compact clusters. Growing with slender stems 15 to 30 centimeters tall, it forms dense mats covered in fine, stiff hairs. Its compound leaves have multiple small leaflets densely covered in minute, stiff white hairs, particularly along the leaf margins and midrib. The plant's distinctive hairy texture and ability to thrive in harsh, dry environments make it a resilient species of the high desert landscape.
Identification and appearance
Key characters: Geographically isolated; no sympatric species
Habitat and range
Habitat: dry barren areas, sand to volcanic ash
Elevation: 1200-1400 m
California counties: Lassen
Outside California: to Oregon, Idaho, Nevada
Bloom period
Astragalus iodanthus var. diaphanoides blooms Apr-Jun.
Conservation status
CNPS 4.3
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 iodanthus var. diaphanoides native to California?
Yes. Astragalus iodanthus var. diaphanoides is native to California (recorded as native).
When does Astragalus iodanthus var. diaphanoides bloom?
Astragalus iodanthus var. diaphanoides blooms Apr-Jun.
Where in California does Astragalus iodanthus var. diaphanoides grow?
Astragalus iodanthus var. diaphanoides occurs in Lassen, at elevations of 1200-1400 m.
What plant family does Astragalus iodanthus var. diaphanoides belong to?
Astragalus iodanthus var. diaphanoides is in the Fabaceae family, genus Astragalus.
Is Astragalus iodanthus var. diaphanoides rare or endangered?
Astragalus iodanthus var. diaphanoides carries California Rare Plant Rank 4.3, state rank S3.
Related species
Other California species in the same genus, family, or bioregion.
- Astragalus iodanthus var. iodanthus — Humboldt river milkvetch
- Astragalus jaegerianus — Lane mountain milkvetch
- Astragalus johannis-howellii — Long valley milkvetch
- Astragalus kentrophyta — Kentrophyta milkvetch
- Astragalus kentrophyta var. danaus — Sweetwater mountains milkvetch
- Astragalus kentrophyta var. elatus — Spiny-leaved 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.