Herb: Flax

Latin name: Linum usitatissimum

Family: Linaceae (Flax Family)

Medicinal use of Flax:

Linseed has a long history of medicinal use, its main effects being as a laxative and expectorant that soothes irritated tissues, controls coughing and relieves pain. The seed, or the oil from the seed are normally used. The seed is analgesic, demulcent, emollient, laxative, pectoral and resolvent. The crushed seed makes a very useful poultice in the treatment of ulceration, abscesses and deep-seated inflammations. An infusion of the seed contains a good deal of mucilage and is a valuable domestic remedy for coughs, colds and inflammation of the urinary organs. If the seed is bruised and then eaten straight away, it will swell considerably in the digestive tract and stimulate peristalsis and so is used in the treatment of chronic constipation. The oil in the seed contains 4% L-glutamic acid, which is used to treat mental deficiencies in adults. It also has soothing and lubricating properties, and is used in medicines to soothe tonsillitis, sore throats, coughs, colds, constipation, gravel and stones. When mixed with an equal quantity of lime water it is used to treat burns and scalds. The bark and the leaves are used in the treatment of gonorrhoea. The flowers are cardiotonic and nervine. The plant has a long history of folk use in the treatment of cancer. It has been found to contain various anticancer agents.

Description of the plant:


70 cm
(2 feet)

to July

Habitat of the herb:

Not known in the wild.

Edible parts of Flax:

Seed - raw or cooked. The seed contains 30 - 40% oil, which comprises mainly linoleic and linolenic acids. The seed also contains cyanogenic glycosides (prussic acid). In small quantities these glycosides stimulate respiration and improve digestion, but in excess can cause respiratory failure and death. Cultivars low in these glycosides have been developed and large quantities of the seed would need to be eaten to achieve a harmful dose. The seed is used in breads and cereals, it can also be sprouted and used in salads. The seed is hard to digest and provokes flatulence. A nutritional analysis is available. The roasted seed is said to be a coffee substitute. A herbal tea can be brewed from the seed. An edible oil is obtained from the seed, though it needs to be properly refined before it can be eaten. Some caution is advised in the use of the seeds for food since some varieties of this plant contain toxins.

Other uses of the herb:

A fibre is obtained from the stem. It is of very high quality and is used in making cloth, sails, nets, paper, insulating material etc.The best quality flax fibre is used for making cloth. It is soft, lustrous and flexible, although not so flexible or elastic as cotton or wool. It is stronger than cotton, rayon or wool, but weaker than ramie. Lower quality fibre is used in manufacturing of towelling, matting, rugs, twines, canvas, bags, and for quality papers such as printing currency notes. The plant is harvested just after it flowers. The yield is 0.5 to 0.9 tonnes of fibre per hectare. When used for paper making, the stems are harvested in late summer or autumn when they are two thirds yellow and are then retted. The fibre is then stripped from the stem, cooked for two hours or more with lye and then beaten in a Hollander beater. The lower quality flax straw from seed flax varieties is used in the manufacture of upholstery tow, insulating material, rugs, twine, and paper. Some of the better quality straw is used in the manufacture of cigarette and other high-grade papers. The seed contains 38 - 40% of a drying oil. It has a very wide range of applications. The paint and varnish industries consume about 80% of all the linseed oil produced. The remainder is used in items such as furniture polish, enamels, linoleum, oilcloth, printer's inks, soap making and patent leather. It is also used as a wood preservative and as a waterproofing for raincoats, slickers, and tarpaulins. The oil is also used in a spray on concrete roads to prevent ice and snow from sticking - it has the additional benefit of helping to preserve the concrete and prevent surface cracking and wear. Yields of over 4 tonnes of seed per hectare have been recorded in N. America, but yields of 2 tonnes or less are more common. A mucilage from the soaked or boiled seeds is used as a size for linen warps.

Propagation of Flax:

Seed - sow early to late spring in situ. Do not transplant the seedlings.

Cultivation of the herb:

Not known in the wild.

Known hazards of Linum usitatissimum:

The seed of some strains contain cyanogenic glycosides in the seed though the toxicity is low, especially if the seed is eaten slowly. It becomes more toxic if water is drunk at the same time. The cyanogenic glycosides are also present in other parts of the plant and have caused poisoning to livestock.

Plant information taken from the Plants For A Future.