Claro: the West Coast walnut.

Although its name "claro" implies a clear interpretation, the derivation of this West Coast walnut is anything but that.

Exclusive to the United States, claro walnut, also known as California walnut, is but one of many of the so-called "true" walnuts. These include American black walnut, European walnut, French walnut, Persian walnut and a host of others, all falling under the general species Juglans.

According to Larry Frye, executive director of the Fine Hardwoods/American Walnut Assn., "There is considerable confusion about which Juglans actually produces claro walnut. Some say it is Juglans hindsii or Juglans californica, the walnuts considered to be natives of the West Coast. Others argue that claro walnut is actually European walnut (Juglans regia) or American black walnut (Juglans nigra.) And a third theory attributes the trees to a grafting of Juglans regia onto the root stock of Juglans nigra," Frye said.

Gary Goby, an Oregon physician and owner of Goby Walnut Wood Products, calls claro walnut a "wastebasket term." "I think of claro as more of a descriptive term. When customers calls for claro, I ask them what they mean by that. Usually they are asking for a certain color or pattern."

A burr plus a curl is a burl

Highly distinctive grain patterns are known as burrs or burls. According to Frye, burr is the antiquated name or Old English term and burl is the common, contemporary description for an abnormal wart-like growth or excrescence which is often produced by stooling.

Stooling happens when a tree grows shoots from the stump, producing a second growth from the original roots. With burrs and burls, an injury or irritation can cause stunted growth, which causes the tree to develop a contorted, gnarled mass of dense woody tissue. This tissue produces a highly decorative appearance of tightly clustered dormant buds, each with a darker pith.

During the golden age of walnut as a furniture wood, 1600-1720, the most prized examples of walnut reportedly came from the burrs and curls. "These pieces were often cut from the cancerous growths on the side of the tree and where branches forked," said Luke Hughes, in "The Encyclopedia of Wood." Another good source is the roots. Because the roots yield such unusually beautiful wood, walnut trees are often felled by digging a large trench around the tree to capture the below-ground wood.

A beautiful burl

Claro walnut grows in California, Oregon, and Washington. Frye said that it is an excellent source for walnut burl. "Any other burls are usually freaks among walnuts and not as common.

"The price of the claro walnut burl is high, because of the labor involved in bringing the burl to market," Frye said. "First, the trees can be huge. Often the stump is involved and cutting it requires digging. The heavy wood then must be transported. Handling at the mills can add to the expense," said Frye, "because the often odd-shaped logs are difficult to slice."

Frye noted that the beautiful result of all the hard work is a price many are willing to pay. However, the supply is limited.

Instead of the traditional walnut coloring, the true claro features black and orange marbling and tends to be softer with a lower density, Goby said, Hybrids of the walnut trees produce a stronger, more dense wood but with similar colors.

Goby said that walnut hybrids can produce widely varying wood colors. He and others have organized the Oregon chapter of the National Walnut Council to encourage people to plant more uniform stands and manage the developing trees. Goby cuts 50,000 board feet a year in his mill of mostly Oregon black walnut.

Goby calls the walnut trees found in Washington and Oregon "Oregon black walnut." "The term claro doesn't mean much. Occasionally you may see pure Hinds (Juglans Hindsii) and some English walnut (Juglans regia) but the majority of the walnut here is hybrid," Goby said.

West Coast walnut is used primarily by custom furniture makers. It is also found in a variety of other products including turnery, gunstock blanks, and such specialty items as gear shift knobs and chopsticks. Oregon black walnut is also used to make museum stands; one will be used to display art in the White House, said Goby.

Claro walnut is often a veneer wood because the timber that produces burrs and burls is often unstructurally sound. Gluing thin slices of the distinctly grained burls onto a plain, solid base wood makes good use of the limited amount of claro walnut.

Fast growing tree

Claro walnut grows quickly and produces wood that is heavy and hard with a slightly open grain. According to Goby, Oregon black walnut trees mature by 130 years and can reach 4-foot diameters by 62 years. Mature trees average heights of 105 feet with 5-foot diameters.

In California, the Northern California walnut, Juglans Hindsii or Hinds walnut, was a favorite with settlers who used the lumber in much the same way as black walnut was used in the East. Three West Coast areas were particularly thick with walnuts: the valley of Walnut Creek in Contra Costa County, the banks of the Sacramento River, especially at Walnut Grove and in Wooden Valley near Napa, Calif. But today the tree is found naturally in many other parts of California.

However, native California walnuts do not produce the walnuts prized for eating. Nuts from the Northern California walnut are larger than the very small California walnut but not worth eating compared to the fruit of the eastern black walnut or the commercial English walnut.