Linum usitatissimum

Morphological description

Cultivated flax is an annual herbaceous plant that reaches a height between 20 and 80 cm. The habit is scapose, meaning it has an elongated floral axis, often leafless, with a generally simple, erect and glabrous stem, smooth surface and tough consistency. The leaves are alternate, linear-lanceolate in shape, with entire margins and herbaceous texture; the size varies from 1 to 4 cm in length and 1.5–3 mm in width, with three prominent veins.

The flowers are solitary, placed at the apex of the floral axis in a scorpioid cyme 5 to 15 cm long. They have a scapose habit, elevated, and are characterized by five elliptic or ovate sepals, 6-9 mm long, with membranous margins and ciliate on the upper part. The petals, about 12-15 mm long (about three times the length of the calyx), are intense blue or white, lanceolate in shape, and open shortly before anthesis. The stigmas are claviform and exceed 0.8 mm in length.

The fruit is a woody capsule, oval in shape, 6-9 mm long and 5-15 mm wide, containing five double locules. The seeds are flattened, oily, brown in color, 3-4 mm long and have a characteristic apex. The root system is not particularly developed, typical of cultivated annual plants, with relatively shallow roots.

Habitat and distribution

Cultivated flax is a species of uncertain origin, probably derived from Linum bienne through artificial selection. It is present throughout the Mediterranean basin and in the neighboring areas of Central Europe and Western Asia, but it is found only as a cultivated plant or occasionally naturalized following cultivation. It is not recorded as truly wild.

In Italy and the Mediterranean it grows mainly in hilly and mountainous environments, up to about 1200 m altitude, often in ruderal areas or cultivated soils. It prefers sunny exposures and well-drained soils, although its traditional cultivation is now almost abandoned. The species adapts to different soil types but is generally grown in fertile and moderately moist substrates.

Flowering period

Flowering mainly extends from May to July, with possible variations depending on altitude and latitude. In Italy, the flowering phase is concentrated in late spring and early summer, when the blue or white flowers open to allow pollination.

Ecology and pollination

Cultivated flax reproduces mainly through entomogamous pollination, with the intervention of pollinating insects attracted by the bright color of the blue or white petals. The floral structure, with long petals and prominent stigmas, facilitates pollination by bees and other pollinating insects.

Seed dispersal occurs mainly through direct fall from the mature capsule, which opens to release the flattened and oily seeds. In cultivation, harvesting is done manually or mechanically before the capsules fully open to prevent spontaneous dispersal.

Curiosities and traditional uses

Cultivated flax is one of the oldest known textile plants, cultivated for over 5000 years in Mesopotamia, Egypt and prehistoric Europe, as evidenced by archaeological finds. It has traditionally been cultivated for the fiber obtained from the stem, used for the production of fine fabrics, and for the seeds, from which linseed oil is extracted, known for its high content of unsaturated fatty acids and dietary and medicinal properties.

Flax fiber was obtained by maceration of the stems and subsequent spinning, and for millennia it was the most important textile fiber in Europe and the Mediterranean, only recently replaced by cotton, jute and synthetic fibers. In Italy cultivation is now almost abandoned.

Flax seeds are used in food, especially in animal husbandry, and for the production of flour and oil, also employed in medicine for their emollient and laxative properties. In folklore and popular culture flax has a symbolic value linked to purity and domestic protection.

Etymology

The scientific name Linum derives from the Greek λίνον (línon), later passed into Latin as linum, which indicates the flax plant. The specific epithet usitatissimum is a Latin superlative meaning "very used", "very common", emphasizing the historical and cultural importance of the species.

The common Italian name “lino” also derives from Latin linum, and is present in many European languages with similar roots (e.g. French lin, German Lein). The word reflects the long tradition of use of the plant for fibers and edible seeds.

Sources

• Prof. P.V. Arrigoni, "Flora analitica della Toscana", "Flora dell'Isola di Sardegna"
• Acta Plantarum - Flora delle regioni italiane (scheda di Giuliano Salvai)
• World Flora Online (WFO)