Evening primrose

Blossom of a common evening primrose, seen right after dawn while it is still open

Evening primrose refers to several species of Oenothera, wild flowers native to eastern and central North America. A frequently occuring variety is Oenothera biennis, called common evening primrose or evening star because its showy, bright yellow blossoms open at night and close during the daytime. Its plants have a two-year life cycle (that is, they are biennial) and can range in height from 10 inches several feet. Pollinated by bees, they are also frequently deliberately cultivated by gardeners.

Full view of a common evening primrose plant