Edible flowers can be considered tasty, healthy and beautiful toppings for your dishes. So why not try growing them in your garden or terrace like any useful plant in the kitchen? More than 125 species are part of the genus Oenothera, but among the most widespread and interesting, Oenothera biennis is a herbaceous plant belonging to the Onagraceae family.
It has numerous vulgar names by which it is perhaps best known including Bella di notte, Enagra, Rapunzia, Asinina grass, Evening primrose and “gardeners’ ham”. It is a plant native to North America that came to Europe in 1600 as an ornamental plant and only later as an edible plant. As the name itself implies, Oenothera biennis is a plant that develops in two years: during the first year it produces the basal leaves with the classic rosette arrangement, in the second year it develops an erect stem (up to 150 cm) and little branched. The basal leaves, oblong and oval, are dotted with small red spots, while the leaves of the stem, oblong and alternate, are lance-shaped with an irregularly serrated edge.
The flowers, gathered in the apical part, are large (3 or 4 cm in diameter), solitary, of a beautiful bright yellow and with four petals. The stem is simple, robust and with many leaves, while the roots are large and fleshy. Oenothera biennis grows spontaneously in uncultivated and arid places, in sandy or alluvial soils, from plains to mountains up to 1200 m. As for its cultivation, it needs a moist, well-drained soil made up of peat mixed with sand. Fertilization must take place only if necessary with a slow-release granular fertilizer every 3 or 4 months.
Exposure must be in full sun and protected from the cold. The Oenothera should be watered regularly, especially during its growth. Its multiplication occurs by seed, which must be collected with all the fruit after the flowering of the plant; the seeds must be planted in deep holes in April. It is a plant resistant to animal parasites, but it fears root rot caused by stagnation of water. In the language of flowers, Oenothera biennis means volubility and inconstancy.
The difference compared to other edible plants is that nothing is thrown away from Oenothera biennis: not only are the flowers edible, but the whole plant is. The roots can be boiled and eaten in salads or stews or they can be taken in the form of an infusion against whooping cough thanks to its components (mucilage, tannins and mineral salts). Oenothera oil, obtained from the seeds, on the other hand has an anti-inflammatory action and is able to give results in the treatment of some dermatological problems (acne, urticaria, psoriasis, atopic dermatitis); it helps in diseases such as rheumatoid arthritis and multiple sclerosis, but also in premenstrual syndrome and asthma.
Moreover, thanks to its elasticizing power, it is also heavily used in cosmetics. In turn, the flowers can be taken in the form of decoction or infusion and, thanks to their components (mucilage, waxes and yellow pigments), they have sedative properties in case of cough and whooping cough. The British call this plant “Evening primrose” because its flowers open in the evening and stay open for the next two nights. A little less romantically, the American Indians rubbed the roots of this plant on their shoes to prevent animals from perceiving the smell of man.