Flax
Flax, also known as common flax or linseed, is a flowering plant, Linum usitatissimum, in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. In 2022, France produced 75% of the world's supply of flax.
Textiles made from flax are known in English as linen and are traditionally used for bed sheets, underclothes, and table linen. Its oil is known as linseed oil. In addition to referring to the plant, the word "flax" may refer to the unspun fibers of the flax plant.
The plant species is known only as a cultivated plant and appears to have been domesticated just once from the wild species Linum bienne, called pale flax. The plants called "flax" in New Zealand are, by contrast, members of the genus Phormium.
Description
Several other species in the genus Linum are similar in appearance to L. usitatissimum, cultivated flax, including some that have similar blue flowers, and others with white, yellow, or red flowers. Some of these are perennial plants, unlike L. usitatissimum, which is an annual plant.Cultivated flax plants grow to tall, with slender stems. The leaves are glaucous green, slender lanceolate, long, and 3 mm broad.
The flowers are 15–25 mm in diameter with five petals, which can be coloured white, blue, yellow, and red depending on the species. The fruit is a round, dry capsule 5–9 mm in diameter, containing several glossy brown seeds shaped like apple pips, 4–7 mm long.
Taxonomy
The scientific name for flax was coined by Carl Linnaeus in his book Species Plantarum in 1753.Varieties
According to Plants of the World Online the flax species has two botanical varieties, Linum usitatissimum var. usitatissimum and Linum usitatissimum var. stenophyllum.Cultivation
Flax is native to the region extending from the eastern Mediterranean to India and was first domesticated in the Fertile Crescent. The soils most suitable for flax, besides the alluvial kind, are deep loams containing a large proportion of organic matter. Flax is often found growing just above the waterline in cranberry bogs. Heavy clays are unsuitable, as are soils of a gravelly or dry sandy nature. Farming flax requires few fertilizers or pesticides. The plant can reach a height of around 3 feet.History
The earliest evidence of humans using wild flax as a textile comes from the present-day Republic of Georgia, where spun, dyed, and knotted wild flax fibers found in Dzudzuana Cave date to the Upper Paleolithic, 30,000 years ago. Humans first domesticated flax in the Fertile Crescent region. Evidence exists of a domesticated oilseed flax with increased seed-size from Tell Ramad in Syria and flax fabric fragments from Çatalhöyük in Turkey by years ago. Use of the crop steadily spread, reaching as far as Switzerland and Germany by 5,000 years ago. In China and India, domesticated flax was cultivated at least 5,000 years ago.Flax was cultivated extensively in ancient Egypt, where the temple walls had paintings of flowering flax, and mummies were embalmed using linen. Egyptian priests wore only linen, as flax symbolized purity. Phoenicians traded Egyptian linen throughout the Mediterranean and the Romans used it for their sails. As the Roman Empire declined, so did flax production. But with laws designed to publicize the hygiene of linen textiles and the health of linseed oil, Charlemagne revived the crop in the eighth century CE. Eventually, Flanders became the major center of the European linen industry in the Middle Ages. In North America, colonists introduced flax, and it flourished there, but by the early 20th century, cheap cotton and rising farm wages had caused production of flax to become concentrated in northern Russia, which came to provide 90% of the world's output. Since then, flax has lost its importance as a commercial crop, due to the easy availability of more inexpensive synthetic fibres.
Diseases
Production
In 2022, world production of raw or retted flax was 875,995 tonnes, led by France with 75% of the total. One of the largest regions in France for flax production is Normandy with nearly one-third of the world's production.Harvesting
Maturation
Flax is harvested for fiber production after about 100 days, or a month after the plants flower, and two weeks after the seed capsules form. The bases of the plants begin to turn yellow. If the plants are still green, the seed will not be useful, and the fiber will be underdeveloped. The fiber degrades once the plants turn brown.Flax grown for seed is allowed to mature until the seed capsules are yellow and just starting to split; it is then harvested in various ways. A combine harvester may either cut only the heads of the plants, or the whole plant. These are then dried to extract the seed. The amount of weeds in the straw affects its marketability, and this, coupled with market prices, determines whether the farmer chooses to harvest the flax straw. If the flax straw is not harvested, typically, it is burned, since the stalks are quite tough and decompose slowly. Formed into windrows from the harvesting process, the straw often clogs up tillage and planting equipment. Flax straw of insufficient quality for fiber use can be baled to build shelters for farm animals, sold as biofuel, or removed from the field in the spring.
Two ways are used to harvest flax fiber, one involving mechanized equipment, and the second method, is more manual and targets maximum fiber length.
Harvesting for fiber
Mechanical
Flax for fiber production is usually harvested by a specialized flax harvester. Usually built on the same machine base as a combine, but instead of the cutting head, it has a flax puller. The flax plant is turned over and is gripped by rubber belts roughly 20–25 cm above ground, to avoid getting grasses and weeds in the flax. The rubber belts then pull the whole plant out of the ground with the roots so the whole length of the plant fiber can be used. The plants then pass over the machine and are placed on the field crosswise to the harvester's direction of travel. The plants are left in the field for field retting. The mature plant can also be cut with mowing equipment, similar to hay harvesting, and raked into windrows. When dried sufficiently, a combine then harvests the seeds similar to wheat or oat harvesting.Manual
The plant is pulled up with the roots, so as to maintain the maximum fiber length. After this, the flax is allowed to dry, the seed capsules are removed, and the straw is retted, where an enzymatic action, or microbial digestion, degrades the pectins that bind fibers to the straw. Retted flax straw is cleaned and dried, and stored until fibre extraction.Processing
is the process of removing the seeds from the rest of the plant. Separating the usable flax fibers from other components requires pulling the stems through a hackle and/or beating the plants to break them.Flax processing is divided into two parts: the first part is generally done by the farmer, to bring the flax fiber into a fit state for general or common purposes. This can be performed by three machines: one for threshing out the seed, one for breaking and separating the straw from the fiber, and one for further separating the broken straw and matter from the fiber.
The second part of the process brings the flax into a state for the very finest purposes, such as lace, cambric, damask, and very fine linen. This second part is performed by a refining machine.
Uses
Flax is grown for its seeds, which can be ground into a meal or turned into linseed oil, a product used as a nutritional supplement and as an ingredient in many wood-finishing products. Flax is also grown as an ornamental plant in gardens. Moreover, flax fibers are used to make linen. The specific epithet in its binomial name, usitatissimum, means "most useful".Flax fibers taken from the stem of the plant are two to three times as strong as cotton fibers. Additionally, flax fibers are naturally smooth and straight. Europe and North America both depended on flax for plant-based cloth until the 19th century, when cotton overtook flax as the most common plant for making rag-based paper. Flax is grown on the Canadian prairies for linseed oil, which is used as a drying oil in paints and varnishes and in products such as linoleum and printing inks.
Linseed meal, the by-product of producing linseed oil from flax seeds, is used as livestock fodder.
Flax seeds
Flax seeds occur in brown and yellow varieties. Most types of these basic varieties have similar nutritional characteristics and equal numbers of short-chain omega-3 fatty acids. Yellow flax seeds, called solin, have a similar oil profile to brown flax seeds and both are very high in omega-3s.Flax seeds produce a vegetable oil known as flax seed oil or linseed oil, which is one of the oldest commercial oils. It is an edible oil obtained by expeller pressing and sometimes followed by solvent extraction. Solvent-processed flax seed oil has been used for centuries as a drying oil in painting and varnishing.
Culinary
A 100-gram portion of ground flax seed supplies about of food energy, 41g of fat, 28g of fiber, and 20g of protein. Whole flax seeds are chemically stable, but ground flax seed meal, because of oxidation, may go rancid when left exposed to air at room temperature in as little as a week. Refrigeration and storage in sealed containers will keep ground flax seed meal for a longer period before it turns rancid. Under conditions similar to those found in commercial bakeries, trained sensory panelists could not detect differences between bread made with freshly ground flax seed and bread made with flax seed that had been milled four months earlier and stored at room temperature. If packed immediately without exposure to air and light, milled flax seed is stable against excessive oxidation when stored for nine months at room temperature, and under warehouse conditions, for 20 months at ambient temperatures.Three phenolic glucosides—secoisolariciresinol diglucoside, p-coumaric acid glucoside, and ferulic acid glucoside—are present in commercial bread containing flax seed.