Linen Flax, Linseed

Linum usitatissimum - L.

Edible Uses

Edible Parts: Seed.

Edible Uses: Coffee; Oil.

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. 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. It is nessary to crack the seed before eating it in any way, because otherwise the seed passes through whole and no nutrition is gained. 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.

Medicinal Uses

Analgesic; Cancer; Cardiotonic; Demulcent; Emollient; Expectorant; Laxative; Nervine; Pectoral; Resolvent; VD.

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, and is a source of vitamin B17.

Other Uses

Biomass; Fibre; Gum; Insulation; Oil; Size.

A fibre is obtained from the stem. It is of very high quality and is used in making cloth, (linen) 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.

Cultivation details

Prefers a light well-drained moderately fertile humus-rich soil in a sunny sheltered position. Plants grow best in a well-drained, loamy soil, those overlying a clay subsoil produce the best results.Very light highly fertile soils are not desirable as they produce tall rank growth tending to lodge. Plants are more sensitive to salt than most field crops. Prefers a cool moist climate during the growing season, dry weather making the plants short and woody. A very greedy plant, like corn, depleting the soil and requiring a rich, well prepared soil if it is to do well. Plants help to break up organic matter and prepare the soil for following crops. Cultivars selected for seed production succeed under a fairly wide range of conditions, but those selected for fibre production require abundant moisture and cool weather during the growing season, and warm dry weather during harvesting, especially where water-retting is practiced. A golden seed form is available, a sort of caramel colour, which has a sweeter flavour. It will breed true to type a second time, so it's probably not a hybrid.

The crop requires 15 - 20cm of rainfall if spread evenly over growing season, with 2.5 cm falling just before or after planting. The plant needs a relatively long ripening period between flowering and harvesting. Warm, dry weather is desirable at the heading stage to cause plants to branch and produce seed; after vegetative growth, dry weather is required for curing the seed[269]. Linseed has a very long history of cultivation in temperate climates with evidence to show that it was being grown in Egypt over 5,000 years ago[269]. It fell into almost complete disuse in Britain in the 20th century as artificial fibres were increasingly used, but it is once again coming into prominence both as a fibre and as an oilseed crop(1995). Linseed is grown for its edible seed, the oil from the seed and for the fibres obtained from the stems. There are many named varieties, though these usually fall within with two classes. One class, generally known as flax, does not branch much and is grown mainly for the fibre in its stem, whilst the other class, known as linseed, branches much more freely and is grown mainly for its seed. Although classified as a species, linseed is possibly an ancient cultigen derived in cultivation from L. bienne. Flax crops take 3 - 4 months to reach maturity, though autumn or early spring sown crops can take 6 - 7 months. Lolium specis (Rye grasses) and Phleum species (Timothy grass) have allelopathic effects on Linum, reducing its carbohydrate synthesis. Linseed is a good companion plant for potatoes and carrots but is inhibited by Camelina sativa.

Seed - sow early to late spring in situ 5 cm apart for maximim seed results. Do not transplant the seedlings.