Because of the Snake River's geographical isolation there are a number of plants that have evolved in Hells Canyon that grow nowhere else on earth. Though some species are more widespread, the specific varieties of the species are not.

List of plants endemic to Hells Canyon

• Arabis crucisetosa Constance and Rollins
• Boechera hastatula Greene
• Astragalus arthurii M.E.Jones
• Astragalus vallaris M.E.Jones
• Calochortus macrocarpus var. maculosus (A.Nels. & J.F.Macbr.) A.Nels. & J.F.Macbr.
• Erythranthe hymenophylla R.J. Meinke
• Lomatium rollinsii Mathias and Constance
• Lomatium serpentinum (M.E.Jones) Mathias
• Phlox colubrina Wherry and Constance
• Ribes cereum var. colubrinum C.L.Hitchc.
• Rubus bartonianus M.E.Peck^[1]