Although native, most local black walnut trees, Juglans hinsdii, are secondary growth from the rootstock of what were once grafted English walnuts, or descendents of such trees. (English walnut trees are grafted onto black walnut understock.) However, the massive old trees that flank the old Monterey Highway south of San Jose were planted as large shade trees nearly a century ago. They are now about sixty feet tall, with lofty broad canopies. Their foot long leaves are pinnately compound, with about eleven to nineteen slightly dentate leaflets that are about three or four inches long. The hard nuts and thick husks are far too messy for refined gardens.