Oenothera biennis, commonly known as evening primrose, is a biennial flowering plant native to North America. It typically grows to a height of 3 to 5 feet and produces bright yellow flowers that bloom in the evening and close by morning. The plant thrives in a variety of habitats, including fields, roadsides, and disturbed areas. The seeds of Oenothera biennis are rich in gamma-linolenic acid (GLA), an essential fatty acid that is often used in dietary supplements and skin care products. The plant has been traditionally used in herbal medicine for various ailments, including skin conditions and hormonal imbalances.