Evening primrose

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

Full view of a common evening primrose plant

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

Evening primrose grow both in the wild, where some people may regard them as weeds, and under cultivation where they are prized for their late spring blossoms.