As the game sits right now, flax is only used as a binding material for clothing. Flax was used, and is still being used, to produce food in the form of flax seeds and linseed oil. The fiber that makes up the stalk is spun into linen, which lacking other clothing would still be something.
Similarly, hemp can be used for food production in the form of hemp seeds and clothing, either 100% hemp or a blend of hemp and flax. Hemp was used to make rope and canvas.
Both flax and hemp have a long history of use. The game shouldn't ignore them, especially considering summer temperature in game have reached 33 degrees Celsius or more.