Oenothera biennis

Oenothera biennis, the biennial Evening Primrose, also known as Fever Plant, Field Primrose or German Rampion, is a tall biennial plant introduced from North America that has become familiar in our landscapes. It is easily spotted in summer during evening walks, in uncultivated areas where its flowers shine with an almost fluorescent yellow colour and a pleasant scent. The biennial Evening Primrose is cultivated in vegetable gardens for its fleshy root which is edible once cooked, or in ornamental gardens where it generously self-seeds if left to nature. Sow directly in the ground in spring or late summer. Grow in sunny, well-prepared ordinary soil.

Oenothera biennis is a biennial herbaceous plant belonging to the Onagraceae family. It is native to central and eastern North America and naturalised worldwide. It is cultivated in gardens for its ornamental qualities, as a vegetable, or for its medicinal and culinary properties. This plant provides the precious evening primrose oil extracted from its seeds. It is used in cosmetics and herbal medicine.

The biennial Evening Primrose forms a large clump of angular, upright, and ramified stems over the course of two years, measuring between 70 cm (28in) and 1.30 m (4ft) in height when flowering, depending on the richness and depth of the soil. In the first year, it only forms a basal rosette. Its leaves are quite long, light green, marked with an almost white vein. The lamina is entire, lanceolate in shape, flexible, and covered with fine hairs. The flowering period extends from June to September in the second year. The cup-shaped flowers consist of 8 lemon yellow to sulfur yellow petals. They open in the late afternoon and wither at sunrise. New buds bloom each evening. Pollination is carried out by nocturnal pollinators. The fruit of this evening primrose measures 2 to 3 cm (1in) in length and contains seeds that ripen when the plant reaches the end of its life and dries up. If the fruits are not destroyed, the evening primrose self-seeds abundantly. Note that the seeds are sought after by certain birds such as tits, finches, accentors, and goldfinches...

The biennial Evening Primrose provides us with the most beautiful spectacle when its flowers open for the night. Their unfolding is visible to the naked eye. In ornamental gardens, it can be sown in a flowery meadow, alongside viper's bugloss, field scabious, and mulleins, for example. The Evening Primrose, also known as 'gardener's ham,' is sometimes cultivated as a vegetable in the fertile soil of the vegetable garden, as its large taproots reportedly have the colour of ham and a slightly sweet and peppery flavour with hints of smoked meat. The roots should be harvested at the end of the first year of growth, before the plant exhausts its reserves in flowering. The leaves that form the basal rosette in the first year of growth can also be consumed, added to soups and stews. The older leaves can be eaten in salads, like frisée lettuce, after being deprived of light. This certainly piques our curiosity and why not pair it with Mertensia maritima, the plant with an oyster-like taste.