Flaxseed is also often known as linseed. It is a plant harvested for it's seeds, they can be used to make vegetable oil or a groundmeal which can be used in baking and as a health supplement.
Lin u 2 is the name of the allegen in flaxseed. This is a 2S seed storage albumin. These types of proteins are found in many seeds and nuts.
There are no known syndromes associated with flaxseed allergy at this time.
Other food containing 2S albumin seed storage proteins are brazil nuts, cashews, peanuts, almonds, mustard seed, rapeseed, turnip, chickpeas, hazelnuts, pistachio, buckwheat, soya beans, sunflower seeds, walnuts, kiwi, castor beans and sesame seeds.