Sidalcea oregana" var. "calva, the Wenatchee Mountains checker-mallow, is a very rare flowering plant variety that occurs only in five locations in the Wenatchee Mountains of Chelan County, Washington, United States. The plant has been placed on the Endangered species list. It is the rarest known plant in Washington state.
the Wenatchee Mountains checker-mallow is on the endangered list because it can only be pollinated by a very specific type of butterfly.