Oenothera biennis

plant

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July 23, 2026

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Oenothera biennis, commonly known as evening primrose, is a species of herbaceous plant belonging to the genus Oenothera within the family Onagraceae. This plant is native to North America and has also been introduced to Europe.1

O. biennis is a biennial, typically growing between 90 to 150 cm (3 to 5 feet) tall. It features alternate leaves and produces yellow flowers that are 2 to 5 cm (0.75 to 2 inches) across. The genus Oenothera is characterized by having nocturnal yellow flowers and is often studied by geneticists to understand principles of heredity.12

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evening primrose
…herbaceous plants of the genus Oenothera, of the family Onagraceae, noted for their showy flowers. The name is especially applied to O. biennis (see photograph), which occurs widely throughout North America and has been introduced into Europe. The true primrose belongs to the family Primulaceae.
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…herbaceous plants of the genus Oenothera, of the family Onagraceae, noted for their showy flowers. The name is especially applied to O. biennis (see photograph), which occurs widely throughout North America and has been introduced into Europe. The true primrose belongs to the family Primulaceae.
Read More