Linum, or flax, is the largest genus within the family Linaceae, consisting of about 200 species of flowering plant, nearly 80% of all Linaceae species. These species are sometimes grown as ornamental plants, but one species L. usitatissimum, is of the most commercial significance. Known as common flax or linseed, L. usitatissimum has been cultivated since ancient times and is used to produce linen fabric, linseed oil, and flax seed. Linum plants have a widespread native range, growing throughout subtropical and temperate regions. Their flowers may be yellow, blue, pink, white, or red.
Common flax, native to the Mediterranean, is one of the oldest plants in cultivation. Its fibers have been used to make linen fabric at least since the days of ancient Egypt. Linum usitatissimum is also cultivated for its seeds, which are used in paints, cattle feed, and cuisine. Flax seeds and flax seed sprouts are high in omega-3 fatty acids and are often considered a health food. The linseed oil present in the seeds also has many important uses, such as in the manufacture of oil paint and linoleum, and as a dietary supplement.
Linum bienne, or pale flax, is also native to the Mediterranean, though it has a wider range than common flax, extending into western Europe and the British Isles. It is grown as a garden plant for its light blue flowers, which bloom in late spring and summer. Pale flax has become naturalized in coastal regions of the United States and in Hawaii.
Fairy flax or L. catharticum is a summer blooming species native to central and eastern Europe and western Asia. L. perenne, called perennial flax or blue flax, is native to high altitude areas of Europe. L. pubescens is a pink flowered plant native to the Mediterranean. The Algerian red flax, L. grandiflorum, is a popular garden plant both for its unusual scarlet flowers and its hardiness. It has been introduced to the British Isles and part of the United States.
There are many New World Linum species as well. L. lewisii, known as Lewis flax or prairie flax, is a light blue flower native throughout western North America. It is grown as a garden plant, particularly in gardens emphasizing native species. L. lewisii is drought tolerant and grows aggressively. L. medium is a yellow flowered eastern North American species.
L. puberulum, or plains flax, is native to dry climates in the western United States. It features bright yellow to orange flowers. L. cratericola is a critically endangered New World species, growing only in the South American country of Ecuador.