Linnaeus named this genus in 1753, and Sereno Watson named this species in 1871 from a specimen collected by Thomas Nuttall near the Green River in 1834.  For several decades in the mid-1800s the plant was known as Acerates latifolia as named by Torrey and Fremont in 1845 from a collection made by Fremont on the Green River in 1844.

  Aesculapius, a legendary Greek physician, was the Greek God of Medicine.  Members of the genus Asclepias have been used medicinally for millennia and are sometimes used in modern herbal teas.

Asclepias cryptoceras  (Pallid Milkweed)
Asclepiadaceae (Milkweed Family)

Semi-desert. Sand, shrublands. Spring.
Canyons of the Ancients National Monument, May 12, 2011 and April 23, 2009.

Asclepias cryptoceras grows on a variety of dry soil types from the Sagebrush to Aspen zones. Flowers are pale yellow with maroon hoods.  The plant sprawls along the ground and sends out clusters of flowers as it grows.

Leaves of Asclepias cryptoceras are very similar to those of Mirabilis multiflora  (photograph immediately below) and the two are found in the same habitat so before they flower the two plants could easily be confused with each other.

Linnaeus named this genus in 1753. "Cryptoceras" means "hidden horn" and refers to the horn-like projection in the hood of the flower. 

Asclepias cryptoceras  (Pallid Milkweed)
Asclepiadaceae (Milkweed Family)

Semi-desert. Sand, shrublands. Spring.
Canyons of the Ancients National Monument, May 12, 2011.

Click to see Waynesword web site for information about the structure of Milkweed flowers.

Asclepias cryptoceras  (Pallid Milkweed)
Asclepiadaceae (Milkweed Family)

Semi-desert. Sand, shrublands. Spring.
Above Yellow Jacket Canyon, April 23, 2009.

The milky juice characteristic of Asclepiadaceae oozes from the plant where I accidentally cracked a leaf base.

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 Asclepias cryptoceras