Medicinal plant Linseed, flax, medicinal plant Common Flax (Linum usitatissimum), linseed, flax or linseed, useful plant, versatile use. Both linseed and linseed oil are used in cooking and in medicine. The mucilages and fatty acids contained help with stomach and intestinal complaints and cough, gastritis, constipation, intestinal inflammation, stomach cramps, heartburn, medicinal herbal use without guarantee