Family: Onagraceae
[Camissonia walkeri subsp. walkeri , more..., Camissonia walkeri var. walkeri (A. Nelson) P.H. Raven, Clylismia walkeri A. Nels., Oenothera multijuga var. orientalis Munz, Oenothera walkeri (A. Nels.) Raven]
Photo ©Al Schneider, swcoloradowildflowers.com