The biennial evening primrose, as already understood, is a biennial plant that often reaches a height of 1 m. Its root is fleshy and juicy 15 cm long. The stem is erect, covered with a little hair, densely covered with leaves, the plant grows only in the second year of its life. In the first year, only a thick rosette of leaves with elongated lanceolate leaves grows. The leaves of the stem are small, alternate, sessile, rarely toothed. The flowers are located in the inflorescence of compound spikes, large, symmetrical, consisting of four petals, bright yellow. They have a strong fragrance, open in the evening and bloom only for one night. Fruits - four-sided elongated pods with many seeds. The plant blooms throughout the summer and the first month of autumn, the fruits begin to appear starting from July.
For medicinal purposes, the above-ground part of the plant is collected, cutting it during flowering, in the evening. Flowers and first-year roots are often collected separately, digging them up in late autumn. The above-ground part is dried by haying the plants in bundles or on sieves, in the fresh air or in well-ventilated rooms, hidden from direct sunlight. Roots and rhizomes are used fresh.
Vegetable oil is obtained from the seeds of the biennial evening primrose. The seeds are collected in autumn, in the second year. Harvesting begins in summer and continues until autumn, harvesting takes place all the time because the plant ripens its fruits unevenly. The collected fruits are dried in fresh air or in forced dryers, not exceeding 50C temperature, then the seeds are removed from the boxes, if necessary, they can also be dried separately.
Evening primrose leaves contain tannins, flavonoids, anthocyanin, cetyl alcohol, triterpene saponins, ascorbic acid, phlobaphenes, pentosans, as well as tannins, resins, mucilages and other organic compounds. A yellow pigment has been found in the flowers, which has not yet been studied. Mucilage, sitosterol, gallic acid and invert sugars have been found in the roots. All parts of the plant contain beta-sitosterol.
The seeds of the plant contain a lot of vegetable oil - up to 24%, which contains gamma-linolenic acid (the substance that makes evening primrose oil so expensive and in demand), as well as tannins.
Evening primrose extract is used orally as an astringent in case of diarrhea. It can also be used to treat cough, spastic asthma and kidney stones. Aqueous extracts from the plant stimulate the stomach, liver and spleen. It is also useful in case of neuralgia of the heart.
Due to the content of various substances, evening primrose oil has medicinal properties that can be used for a wide variety of medical purposes. It is used orally to restore the elasticity of blood vessel walls, as well as to additionally strengthen them in case of cardiovascular diseases.
Often, women use evening primrose oil in an encapsulated form during PMS, although you should not count on this oil to relieve the condition, as it has a strong individual effect on each woman.
A decoction of biennial evening primrose leaves is used to stop severe diarrhea.
Evening primrose has a beneficial effect on the genital system, easing the condition of PMS, easing the climactic period, helping to prevent menstrual cycle disorders.
It has a beneficial effect on lipid metabolism, stimulates weight loss due to the fact that it accelerates the breakdown of triglycerides into fatty acids and glycerol, as well as perfectly prevents the manifestations and symptoms of hangover syndrome, reduces liver decomposition processes.
The leaves of the plant are used in tea to treat diarrhoea, and an alcohol extract is used for this purpose. This property of evening primrose is due to the tannins contained in it.
As a sedative, a decoction of evening primrose leaves is used in neuralgic heart diseases; in case of cough and bronchial asthma - as a spasm-relieving agent.
The decoction of evening primrose can be used to treat ulcers and as a rinse for angina and stomatitis. It is also used in dyspepsia, urinary stones, digestive tract and chronic weakness/exhaustion. The decoction is also used externally to rinse wounds, treat eczema, scabies and various types of rashes.
In case of pulmonary tuberculosis, a decoction of evening primrose roots is used, in case of nephritis, a decoction of flowers.