There are species of walnuts all over the world. The J. Regia, also called the English walnut, is one of the most popular commercial types. The black walnut which grows in North America is also important in the organic trade. Although the latter is a sweet walnut, it has a very hard shell which makes it less popular than the J. Regia. Depending on the use you might ask for these specifics when you are searching for bulk & wholesale nuts. The Brasilian, Californian, Indian, Mexican and other types of walnuts are also available.
It is not only the whole walnut which is available for purchase. Coated walnuts, walnut powder and walnut light quarters and pieces are also important products used widely. People who want to make use of the oils which are present when the walnut gets cracked open, can opt for shelled walnuts. Other products such as biowalnuts in powder form are generally used in the pastry business.