evening primrose family of flowering plants, belonging to the myrtle order (Myrtales), comprising 18 genera and 655 species, and concentrated in the temperate region of the New World. The family is characterized by flowers with parts mostly on the plan of four (four sepals, four petals, four or eight stamens), but there are some exceptions. The ovary is inferior (i.e., below the flower proper).

Britannica Editors. "Onagraceae". Encyclopedia Britannica, 4 Jul. 2019, https://www.britannica.com/plant/Onagraceae. Accessed 17 October 2026.