Oenothera rosea

Native from the southwestern United States through Mexico and Central America to western and southern South America, and also to Cuba and Jamaica, this perennial herb grows from a somewhat woody base. It occurs in disturbed ground and along creeks. Its rose-purple flowers open near sunrise and darken as they age. The species can fertilize itself, with the anthers surrounding the stigma when a flower opens. Its ribbed, club-shaped seed capsules taper into a slender base and split mainly at the tip. It has become naturalized outside the Americas, including in New Zealand. Photographed in Peru.