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.
There is a reward offered if local citizens of Chelan County can find additional locations of where the Wenatchee Mountains checker-mallow is actively growing.