Evening primrose

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.