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Click to read about the Astragalus genus.

Astragalus calycosus

Astragalus calycosus

Astragalus calycosus

Astragalus calycosus (Torrey's Milkvetch)
Fabaceae (Pea Family)

Semi-desert-montane.  Openings.  Spring.
Canyons of the Ancients National Monument. Above: April 19, 2016. Left: April 19, 2007 and April 6, 2012.

Astragalus calycosus
Astragalus calycosus (Torrey's Milkvetch)
Fabaceae (Pea Family)

Semi-desert-montane.  Openings.  Spring.
Canyons of the Ancients National Monument, April 19, 2007.

Astragalus calycosus most often forms a symmetrically round mat of light green, oval, hairy leaves surmounted by numerous leafless flower stalks which lean outward encircling the mound of leaves.  The plant is at home in rocks and sand in the lower Pinyon/Juniper forests and in mountain soils.  It can put on a magnificent bloom, covering hundreds of square feet with many dozens of plants.

John Torrey named this plant in 1871 from a specimen Sereno Watson collected in 1868.  "Calycosus" refers to the conspicuous calyx.

Astragalus calycosus
Astragalus calycosus (Torrey's Milkvetch)
Fabaceae (Pea Family)

Semi-desert-montane.  Openings.  Spring.
Canyons of the Ancients National Monument, April 19, 2007.

Two further characteristic that help identify A. calycosus are the lobed white wing petals and the usually straight, rounded at the bottom, 1-2.5 cm long, hairy seed pods.

Astragalus calycosus
Astragalus calycosus (Torrey's Milkvetch)
Fabaceae (Pea Family)

Semi-desert-montane.  Openings.  Spring.
Canyons of the Ancients National Monument, April 19, 2016.

Leaves are typically several inches long and are divided into 3-13 leaflets which can be a variety of shapes: obovate, spatulate, oblanceolate, or elliptic -- even on the same plant. Leaflet tips vary from obtuse to acute. Leaves (as well as most of the plant) have strigose, malpighian hairs, i.e., the hairs are short, sharp tipped, appressed and attached with a short stem from their middle.

Astragalus calycosus
Astragalus calycosus
Astragalus calycosus (Torrey's Milkvetch)
Fabaceae (Pea Family)

Semi-desert-montane.  Openings.  Spring.
Canyons of the Ancients National Monument, May 12, 2011.

A magnificent year for Astragalus calycosus flowers is followed by a magnificent year for seed production.

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
Eradicated

Questionable presence

Range map for Astragalus calycosus