A plant having a slender, round, hollow stalk, about two feet high; its bark is full of filament3, like hemp; the leaves are long, narrow, and pointed; it bears a blue flower, to which succeeds a roundish fruit, about the size of a pea, containing ten little seeds, full of an oily substance, or meal. There are twenty-five species, of which the most remarkable are the common annual flax, and the perennial Siberian flax.