Evening primrose

Evening primrose (Oenothera) is a genus of plant within the evening primrose family (Onagraceae). Native country: North America. Introduced to Europe in 1620 as an ornamental plant. Now widespread in Europe.

Evening primrose is an annual, biennial or perennial herbaceous plant with a flowering season from June to September.

Many species form taproots, some rhizomes as survival organs. The long, undivided leaves have smooth to lobed margins. The four green to yellowish sepals often have red or purple markings.

The plant produces a dark red to brown seed about 0.1 cm long. Roots and leaves, flowers and seeds are edible.

Phytotherapeutic use is made of the oil obtained from the crushed seeds by hot pressing and refining (refined evening primrose oil - Oenotherae oleum raffinatum).

Herba oenotherae biennis: Tannins, phytosterols, resins, sugar. Popular use for diarrhoea and as "blood purifier".

Oentherae biennis oleum(evening primrose seed oil): 4-10% palmitic acid, 1-4% stearic acid; 5-12% oleic acid, 65-85% linoleic acid, (7-14%) gamma-linolenic acid.

Naturopathic / medicinal: Oenothera biennis is the parent plant of Herba oentherae biennis, the extract from the evening primrose herb, as well as Oenontherae bienis oleum, the evening primrose (seed) oil. In naturopathy today, especially the oleum Oenthera biennis is important (no monogrpahi by the Commission E). Evening primrose (seed) oil is obtained from the seeds of the evening primrose. The gamma-linolenic acid contained in the evening primrose oil in a concentration between 8-14% allows the formation of the anti-inflammatory prostaglandin E1 without a conversion of cis-linoleic acid into gamma-linolenic acid mediated by delta-6-desaturase. Furthermore, other essential fatty acids. Evening primrose oil is used both internally (TD 4-6g oil) and externally (in ointments in creams for dry skin and atopic eczema).

Cosmetics: Oenothera biennis oil (INCI) is the evening primrose (seed) oil used cosmetically.

Empirical medicine: used in prementrual syndrome (indication controversial).

1. https://arzneipflanzenlexikon.info/nachtkerze.php
2. Wenigmann M. (2017) Phytotherapy medicinal drugs, phytopharmaceuticals, application. Urban & Fischer, pp. 163-164
3. https://pflanzen.fnr.de/industrial-plants/medicinal-plants/pflanzen-datenbank.