The common evening primrose, Oenothera biennis, is a biennial herbaceous plant native to the Americas. It has soft yellow flowers that open at sunset. Hence the “evening” in its name.

The open flowers are typically pollinated by moths at night. The seeds are a good food source for birds.

Nearly all parts of the plant are edible (excluding the outer peel of the stems). The taste of the greens is described as “mild lettuce or salad greens”, and the taste of the flowers is described as “lemon-y, slightly sweet”. The roots can also be cooked and eaten like potatoes.

Evening primrose oil is used as an anti-inflammatory for many conditions, but there is currently no solid evidence to support its healing abilities. The oil also contains polyunsaturated fatty acids and is sometimes sold as a dietary supplement for this reason.