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.

  For diagrams explaining the complex Milkweed flower structure, click and then scroll down to #4. Very interesting.     

  Also click to see the ultimate Asclepias page.

  And give one more click for a very interesting and scientifically accurate account of Milkweed pollination.

Asclepias cryptoceras  (Pallid Milkweed)
Apocynaceae (Dogbane Family)
formerly Asclepiadaceae (Milkweed Family)

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

What a fabulously intricately beautifully captivating plant! It is always a thrill to find this plant and I find it very difficult to pull myself away from it. And when I find it growing with Pediomelum megalanthum, I could just sit next to them and spend a few weeks admiring.

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.

The species was first named Acerates latifolia in 1845 by Torrey and Fremont from specimens collected by Fremont near the Green River in 1844. Sereno Watson realized that the plant should be in the Asclepias genus and named the plant Asclepias cryptoceras in 1871 from specimens collected by Nuttall (also along the Green River) in 1834.  

"Cryptoceras" means "hidden horn" and refers to the horn-like projection in the hood of the flower. 

Asclepias cryptoceras  (Pallid Milkweed)
Apocynaceae (Dogbane Family)
formerly Asclepiadaceae (Milkweed Family)

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

Click for Milkweed anatomy.

Asclepias cryptoceras  (Pallid Milkweed)
Apocynaceae (Dogbane Family)
formerly 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