XXIII 



FIBER CROPS 



I. FLAX 



490. Relationships. The genus Linum has been divided into 

 many species, but in many cases the distinctions are of minor 

 importance. The only species of commercial importance is the 

 common flax (Linum usitatissimum L.). There are both spring 

 and winter varieties, the former only being cultivated in Amer- 

 ica. There is a form of summer flax, sparingly cultivated in 

 Europe, in which the capsules or seed bolls burst open and 

 scatter the seed. Perennial flax (L. perenne L.) has been cul- 

 tivated experimentally, but is of no commercial importance. 

 Rocky Mountain flax (L. Icitisii Pursh.), occurring widely 

 throughout sub-arid western North America, has been used by 

 the Indians for making cord, fish-nets, basket frames, and 

 similar purposes. 



491. Description. Flax is an annual with a single, upright 

 branching stem varying under cultivation from one and a half 

 to three or more feet in height. It has a thread-like tap root, 

 sparingly supplied with tender branches. The leaves are simple, 

 narrow, entire, and nearly sessile. It has perfect, symmetrical, 

 rather conspicuous blue flowers, all parts being in fives. The 

 carpels, however, are divided by a false partition, hence the 

 capsule or seed boll is usually ten-celled and ten-seeded. The 

 seed boll is one- fourth inch or more in length, and the seeds 

 vary in length from one-seventh to one-fifth inch. 



492. Flax Seed. The seeds are lenticular, compressed, with 

 a smooth, polished surface, one-sixth to one-fourth inch long, 



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