Asclepias uncialis is a species of flowering plant in the dogbane family known by the common name wheel milkweed. It is native to the western United States. Two subspecies are sometimes described, with ssp. ruthiae containing three plants which are sometimes described as separate species, Asclepias ruthiae, A. eastwoodiana, and A. sanjuanensis. This plant is less common than it was 100 to 150 years ago. It was collected in greater numbers then and appears to have had a larger distribution. There are many historical occurrences that are gone today. There are about 20 occurrences known today.