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 oil, which is often extracted for use in dietary supplements. This oil contains gamma-linolenic acid (GLA), an essential fatty acid believed to have various health benefits, including support for skin health and hormonal balance.