Walnuts are one of the oldest tree foods known to man, dating back to about 7000 B.C. In ancient times walnuts were known as "the nuts of the Gods." In many European languages the generic term for nut is also the word used for walnuts. The Greeks used the walnut for oil long before they discovered the olive.

In Eastern Russia, Mongolia and northern China the walnut tree is tapped in the spring much like the sugar maple in this country. The sap gathered in this manner is used in making syrup and sugar.

Walnuts were once believed to ward off disease and increase fertility, inspiring the custom in some cultures of scattering them like rice at weddings.

Black Walnuts: The black walnut tree grows to a height of 150 feet and is one of the most valuable hardwoods in America. When German-speaking settlers made their way into Pennsylvania, they often chose acreage by the sighting of stands of black walnut trees, which indicated limestone soil that would guarantee rich harvests for their crops.

Throughout Pennsylvania Dutchland -- and in Virginia, West Virginia, Tennessee, the Carolinas and the Midwest -- lavish black walnut cakes are favorites. Black John cake is two layers made from dough that blends brown sugar, molasses, eggs, butter, flour, ginger, cinnamon, buttermilk and baking soda and has a filling accented by raisins, coconut and black walnuts. The Magnolia cake of the Moravian community in North Carolina is made with black walnuts in the dough, instead of the frosting.

Walnuts and Health: Like English walnuts, black walnuts are high in Vitamin E. They are low in saturated fats, have no cholesterol and are high in polyunsaturated and monounsaturated fats (the good fats). Several studies have shown they can lower "bad" cholesterol levels (LDL) without damaging good cholesterol (HDL).

Walnut Sources: Both Diamond and Hammons Products Co. sell black walnuts in bags. Look for them in most grocery stores during the holidays.

On the Internet, visit www.black-walnuts.com. This is the site of Hammons, the chief supplier of black walnuts in this country. It offers interesting recipes and lore.

-- Allen Appel