The walnut like other so called nuts are botanically not classed as a nut but a seed. The edible seed is called a drupe.
The drupe has a green/grey sponge like texture this is called the hull.
Inside there is a ridged uneven wooden shell which holds the nut. In between the two halves of the walnut is a thin membrane which helps to protect the nut.
When the fruit matures, the hull, which becomes hard and brittle, falls away from the hard wooden shell, from the tree.
China holds the record for the world with 51% sales (3.8 million tonnes) yearly. The Chinese walnuts tend to be smaller in size and also have a darker skin than the Californian ones. You can also get walnuts from Iran and Turkey.
Walnuts are available whole, halved or pieces.
They can be eaten raw, toasted or pickled making a protein rich snack.
Walnuts can be added to muesli, granola or as an ingredient for baking such as walnut coffee cake, banana cake, brownies, scones, muffins biscuits and flapjacks.
Walnuts can also be used to decorate cakes or as a topping for ice cream.
Walnuts is the main ingredient in baklava.
Sweet fudge and nougat are a favourite with walnuts pieces added to their mix.
Walnut oil, is rich in good polyunsaturated fatty acids, and can be used straight from the bottle or as a salad dressing.
Walnuts contain 15% protein, 7% dietary fibre and plenty of minerals especially high in manganese and Vitamin Bs, Vitamin A, Vitamin C and Vitamin K.