About Oenothera tetraptera Cav.
Oenothera tetraptera Cav., commonly called fourwing evening primrose, is a species of flowering plant in the Onagraceae (evening primrose) family. It is native to the Americas, and has become widely naturalized across other regions: southern Africa, Europe, Asia, and Oceania. This species was first formally described and named in 1796 by Spanish botanist Antonio José Cavanilles. It grows as an annual or short-lived perennial herb, reaching 15–50 cm (0.5–1.6 ft) in height. Its flowers have four white petals that open around sunset. Individual petals can grow up to 3.8 cm (1.5 in) long, and the flowers fade from white to pinkish purple as they age. The fruit of this species is a hairy, obovoid capsule that measures 7–18 mm in length. 2–3 mm wide wings grow along the capsule's valves, which is the feature that gives the species its scientific and common name.
