Piperia yadonii, also known as Yadon's piperia or Yadon's rein orchid, is an endangered orchid endemic to a narrow range of coastal habitat in northern Monterey County, California. In 1998 this plant was designated as an endangered species by the United States government, the major threat to its survival being continuing land development from an expanding human population and associated habitat loss. One of the habitats of Yadon’s Piperia, the Del Monte Forest near Monterey, California, is the subject of a federal lawsuit, based upon endangerment of this organism along with several other endangered species.