Flax seed (also known as linseed) is native to the region that spans from the eastern Mediterranean to India. This seed is a rich source of omega fatty acids, especially alpha-linolenic acid (omega 3), but to access most of the oils in Flaxseed it is better to break the whole seeds first. It is always better the break them up as and when you need them, because over time the oils will deteriorate.
Flax is also a good source of water soluble fiber. The broken flax seed is the best form if you are taking it for fiber.