Annual plant up to 2m in height; very polymorphic plant, numerous breeds which quality varies with the weather, latitude, land.
The plant is dioecious (two sexes), but there are monoecious varieties.
The plant has been used for millennia as a source of fibres, for its seed oil, as food, as drug, as medicine; each part is harvested differently depending on its use.
It gives rise to two cultures: one for oil and one for fibres. Culture for the fibres is made on fertile land during summer.
The fibres are derived from the peripheral part of the stem; plant must pass a rigorous preparation in order to recover them.
The operation of retting is to place the stems in water for fermentation in order to eliminate the parenchyma surrounding the fibres. Then come the drying, crushing and beating operations to separate the long fibres.