SafePlants

Astragalus lentiginosus

Astragalus lentiginosus is a legume species known by the common names spotted locoweed and freckled milkvetch.

Considerations for Pets

• This plant is also known as "rattleweed" or "loco weed" due to its effect on cattle and horses who consume it.

Taxonomy and Nomenclature

• Scientific Name: Astragalus lentiginosus Douglas ex Hook.
• Common Names: Spotted locoweed, Freckled milkvetch, Rattle pod, Specklepod loco milkvetch, Specklepod Milkvetch.
• Family: Fabaceae (also known as Leguminosae), the pea family.
• Synonyms: A. lentignosus diphysus (Gray.)M.E.Jones.
• Varieties:
  • Astragalus lentiginosus var. albifolius M.E. Jones – northern freckled milkvetch, Owen's Valley milkvetch, northern speckledpod milkvetch.
  • Astragalus lentiginosus var. palans
  • Astragalus lentiginosus var. latus (M. E. Jones) M. E. Jones - BROAD-POD FRECKLED MILKVETCH
  • Astragalus lentiginosus var. negundo &ampmdash Box Elder Freckled Milkvetch
  • Astragalus lentiginosus var. fremontii a/k/a Fremont's Milkvetch

Distribution and Habitat

• Native to western North America.
• Found in semi-desert environments, specifically in openings and canyons.
• Examples of specific locations mentioned include:
  • Canyons of the Ancients National Monument
  • Mojave Desert (below 12000 feet)
  • John Day River area
  • Great Basin National Park, Nevada
  • Carrizo Plain CA
  • Saline Valley, Death Valley National Park, Inyo Co., Calif.
• Also found in Canada (British Columbia), Mexico, and the United States (including Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Idaho, Illinois, Indiana, Iowa and many other states).

Ecological Role

• Grows in dry, open areas.
• May grow under the shade of oaks and junipers, as well as on slopes.

Morphological Characteristics

• Perennial herbs from a taproot, growing to 6.3 inches to 2 feet (1.6 to 6 dm) tall.
• Stems are prostrate to ascending, hairless or coated with silver hairs.
• Leaves are linear to widely oval, divided into 19 oval leaflets. They can grow to 5/8 inches in length and are dark green.
• Seed pods are approximately 1 inch long, hairy, and freckled with red.

Endangered Status

• The Coachella Valley Milk-vetch and the Fish Slough Milk-vetch, subspecies of the Freckled Milk-vetch, are on the U.S. Endangered Species list.

Interactions with Other Organisms

• Serves as a food source, containing nitrogen, phosphorus, and potassium
• The plant can affect cattle and horses if ingested.

Quirky Facts

• It's sometimes called "rattleweed" because of the sound the dried seed pods make.
• Certain subspecies of this plant are endangered.