Flaxseed is the seed from the flax plant, Linum usitatissimum — crushed to produce linseed oil, and eaten whole or ground as a food in its own right. The small, glossy brown or golden seeds are among the richest plant sources of alpha-linolenic acid, the essential omega-3 fatty acid, and they pack soluble fibre in the form of mucilage plus lignan phytochemicals studied for hormonal and cardiovascular effects. Ground flaxseed — the whole seeds pass through undigested — enriches breads, cereals, and smoothies; the oil, pressed from the seed, is the linseed oil of paints and the food oil of omega-3 supplements, though it oxidises quickly and must be kept cold and dark. Flax is the ancient dual-purpose crop — fibre for linen, seed for oil and food — still earning its place in the modern pantry.