Summary:

Evening primrose (Oenothera biennis) is a wild species growing in lighter and barren soils, which for a long time has aroused interest due to its usable value. Its root was used as a vegetable with considerable dietetic values. Interest in evening primrose grew even more by the end of the 20th century when it was discovered that oil in the primrose seeds is rich in unsaturated fatty acids, particularly in linolic and gamma-linolic acids, which beside biological activation of human organism can be successfully used for treatment of various diseases, including Alzheimer disease, allergies, diabetic neuropathy, dementia, hypertension, vascular disease and various consequences of post-viral diseases.
Cultivation of evening primrose on plantations decreases slightly therapeutic values of the oil obtained from seeds, therefore in the Authors' opinion evening primrose seeds should be gathered from wild plants, particularly when it occurs so massively as at Tokarnia in the swietokrzyskie province. The Authors found large numbers of evening primroses growing in light sandy soil covering several dozen of idle arable lands. Spontaneous settling by this species of such large area may be regarded as a some kind of botanical curiosity which inclined the Authors to undertake further studies on this plant.