Oenothera is a genus containing around 157 annual, biennial and herbaceous perennial plants in the Onagraceae family. They are native to the Americas where they act as primary colonisers and are most often found in areas of disturbed soils. Some species are commonly known as Evening Primrose for their yellow flowers that open at night, they are not related to the true primrose family, Primulaceae. They are cultivated for their attractive blooms and long flowering period. They can thrive with some neglect in poor soils and full sun.