Flax (also known as common flax or linseed), with the binomial name Linum usitatissimum, is a member of the genusLinum in the family Linaceae. It is a food and fiber crop that is grown in cooler regions of the world.. The plant species is known only as a cultivated plant, Flaxseed is a popular traditional food and remedy, as flaxseed and flaxseed oil, or linseed oil, contain alpha-linolenic acid (ALA), an omega-3 fatty acid.