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Astragalus pycnostachyus  A. Gray
Loco weed,   Marsh milk vetch,   Marsh milkvetch
© 2019 Brittany Burnett
© 2021 Suzanne L. Weakley
© 2024 El Byrne
© 2022 Lynn Halsted
© 2013 David Magney
© 2019 Brittany Burnett
© 2023 R.A. Chasey
© 2013 David Magney
© 2013 David Magney
© 2008 Toni Corelli
© 2013 David Magney
© 2013 David Magney
Astragalus pycnostachyus is a perennial herb that is native to California, and endemic (limited) to California.
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial
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Bloom Period
Subspecies and Varieties:
Genus: Astragalus
Family: Fabaceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Toxicity: Do not eat any part of this plant.

Wetlands: Occurs in wetlands

Habitat: coastal, salt-marsh

Communities: Coastal Salt Marsh, wetland-riparian

Name Status:
Accepted by JEF + JEF + PLANTS + POWO

Information about  Astragalus pycnostachyus from other sources
Nursery availability from CNPLX
Commercial availability unknown.
Jepson eFlora

USDA PLANTS Profile (ASPY)

Photos on Calflora

Photos on CalPhotos

Google Images

Photos on iNaturalist

ID Tips on PlantID.net

[Wikipedia] Variety Info: he species has two named varieties. Astragalus pycnostachyus var. lanosissimus — Ventura marsh milkvetch,[2] now endemic to the Oxnard Plain in Ventura County, with only one population within Oxnard.[3] The single extant population of this rare plant variety is now fenced and protected. The variety is treated as an endangered species on the federal level.[4][3] Threats to its existence include near-total loss of habitat, infestation by weevils, cucumber mosaic virus infection, competition from non-native plants such as ice plant, and herbivory by the milk snail Otala lactea. Astragalus pycnostachyus var. pycnostachyus — marsh milk vetch, primarily found in the San Francisco Bay Area.[5] (link added by Mary Ann Machi)


Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2025. The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 03/28/2025).