An erect biennial, up to 1.5m (5 ft.) tall, with a thick, yellowish taproot and a rosette of basal leaves from which the flowering stems arise. These have alternate, lance late to ovate leaves, and are topped by bright, yellow flowers, which open at night to release their fragrance and are pollinated by moths. Downy pods follow, containing tiny seeds.
History and traditions
An American native, the evening primrose was introduced to Europe in 1619, when seeds were brought to the Padua Botanic Garden in Italy. Although it had some place in the folk medicine of Native Americans, in Europe it was used more as a culinary than medicinal herb leaves were put into salads and roots cooked as vegetables. It came to prominence after modern research in the 1980s established that oil from the seeds contains GLA, or gammaz-linolenic acid, an unsaturated fatty acid which assists the production of prostaglandins, hormone-like substances, which act as chemical messengers and regulate hormonal systems. It is not related to the primrose, but takes its name because it opens in the evening.
Growth
Grow in open, sandy soil in a warm sunny position. This plant self-seeds freely once established. Propagated from seed sown in autumn or spring.
Parts used
Seeds pressed to produce oil.
Uses
Medicinal
The oil is thought to benefit the immune system and regulate hormones. It is taken internally for premenstrual tension, menopausal problems, allergies, skin complaints, such as eczema and acne, and to counteract the effects of excess alcohol. It may also be helpful for high blood pressure, arthritis and multiple sclerosis.
Cosmetic
The fresh flowers are often made into face masks to improve skin tone. The oil is an ingredient in commercial cosmetics and pharmaceutical products.