WILDFLOWER HOME PAGE     SEARCH BY PLANT NAME     PINK/RED/ORANGE FLOWERS     CONTACT US

    The Astragalus genus is large and complex.  In Colorado Flora, Western Slope William Weber lists over five dozen species with many sub-species.  The new Flora of the Four Corners lists fifty-eight species and several dozen varieties of Astragalus in the Four Corners drainage of the San Juan River.  In Intermountain Flora Arthur Cronquist lists 156 species and 122 varieties.  World-wide there are about 1600 species. 

    Astragalus species are difficult to identify and it is the seed pod, not the flower, that is often crucial in the identification process.

     The common name, "Locoweed", is applied not to one plant but to many members of the Astragalus genus, for many of these plants absorb toxic soil substances, especially selenium, which cause grazing animals a variety of serious ailments.  Further complicating the common name: some people use the name "Locoweed" not only for Astragalus but also for another Pea genus, Oxytropis.  And, making common names even more confusing, many Astragalus also carry the common name of "Milk Vetch" (easily confused with other Peas known as "Vetch").  These common names are so confusing that they really should not be used (except in whispers to close friends). 

    The genus was named by Linnaeus in 1753 and the word "Astragalus" means "ankle bone" in Greek.  It is an ancient Greek plant name perhaps given because of  the seed shape in some members of the Astragalus genus or, the authors of Intermountain Flora conjecture, because the Greeks used rattling bones for dice and the sound made is similar to the rattling of dry Astragalus seeds in the pod.

 

 

Astragalus proximus
Astragalus proximus

Fabaceae (Pea Family)

Semi-desert. Shrublands, openings. Spring.
De-Na-Zin Wilderness Area, April 23, 2007.

Astragalus proximus typically grows numerous leaf and flower stems in a dense mass, and leaflets and flowers are numerous.  Leaflets are long and narrow in an open, airy configuration and flowers are tiny, delicate, and quite handsome.

Astragalus proximus is found only in Colorado and New Mexico.  In Colorado it is rare in three southwestern counties and although more common in three northwestern New Mexico counties, it is still in need of protection there.  Click to read about the plant and its status.

 

Astragalus proximus

Astragalus proximus
Astragalus proximus
 Fabaceae (Pea Family)

Semi-desert. Shrublands, openings. Spring.
De-Na-Zin Wilderness Area, April 23, 2007.

These lovely flowers are only 7 millimeters long.  Carry a hand lens with you on your walks to appreciate such delicate and minute beauty.

Astragalus proximus was first named Homalobus proximus by Per Axel Rydberg in 1905 from a specimen collected at Arboles, Colorado by Charles Baker in 1899.  In 1915 Elmer Wooton and Paul Standley renamed the species Astragalus proximus.
Astragalus proximus
Astragalus proximus
 Fabaceae (Pea Family)

Semi-desert. Shrublands, openings. Spring.
De-Na-Zin Wilderness Area, May 21, 2009.

 

Astragalus proximus produces enormous quantities of seed pods.  Shown here are about 5% of the pods on one plant.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Questionable presence

Range map for Astragalus proximus

WILDFLOWER HOME PAGE     SEARCH BY PLANT NAME     PINK/RED/ORANGE FLOWERS     CONTACT US