It is a crop that has been grown for a long time. In Europe, fibre flax cultivation for linen is concentrated in Belgium and northern France.
The photo shows part of a plot which is produced specifically for propagation seed. The fibre is an additional gain.
The picture shows the plant in full bloom. Flax blooms for only a short period. From morning until around noon!
I tried to make the image so that only one flower is really in focus, creating depth in the photo.