Semi-desert, foothills, montane.  Pastures, meadows, woodlands.  Summer.
Canyons of the Ancients National Monument near Yellow Jacket Canyon, July 5, 2010.

Asclepias subverticillata is a perennial growing from stout rootstock typically to about fifteen inches tall, but it can reach nearly four feet.  It often is found along roadsides and in other disturbed sites.  It blooms for many weeks from early to late summer.  It is a distinctive plant, and can be identified because of its very narrow leaves.

Asclepias subverticillata was first collected for science by Charles Wright in Texas in 1852 and was named Asclepias verticillata variety galioides by Asa Gray in 1858.  Vail renamed it Asclepias subverticillata in 1898.

"Subverticillata" means "almost whorled", referring to the leaf arrangement. Asclepias verticillata (not found in our area) does have leaves in a whorl.

Semi-desert, foothills, montane.  Pastures, meadows, woodlands.  Summer.
Canyons of the Ancients National Monument near Yellow Jacket Canyon, July 5, 2010.

Semi-desert, foothills, montane.  Pastures, meadows, woodlands.  Summer.
Canyons of the Ancients National Monument near Yellow Jacket Canyon, July 5, 2010.

Click for diagrams explaining the complex Milkweed flower structure. (Scroll down to #4.) Very interesting. Also click to see the ultimate Milkweed page.

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 subverticillata