Juglans hindsii, the Hinds' black walnut, also called the Northern California walnut, is a large tree (up to 60 feet tall) endemic to roughly circular area in California centered near Fresno and reaching the San Francisco Bay area. Some authorities (i.e. California Native Plant Society) describe this species as the subspecies hindsii of the Southern California black walnut, J. californica S. Watson. This article uses the The Jepson Manual.^[1][2]

J. hindsii, generally found in the northern half of the state, is a large tree, 30 to 60 feet high, with a single erect trunk commonly without branches for 10-40 feet and a crown which can be wider than the tree is tall. Specimens commonly reach five to six feet in diameter near the base of the tree.^[3] The leaf is approximately 1 ft long, with 13-21 two to five-in leaflets with dentate margins. Unlike the Southern California walnut, the vein angles bear tufts of hair. The nut has a smooth, brown, thick shell containing a small edible nutmeat.^[4]

J. hindsii is endangered, with possibly only a few native stands remaining. It grows in riparian woodlands, either in single species stands or mixed with California's oaks (Quercus) and cottonwoods (Populus). J. hindsii is commercially important as a rootstock for English walnut (Juglans regia) orchards all over the world, both on its own and as a parent to the fast-growing Luther Burbank hybrid, commonly called "Paradox"J. hindsii x J. regia . J. hindsii is cultivated as an ornamental tree wherever it will grow in California, and in Hawaii.

Wood

The wood of J. hindsii is commonly called claro walnut by the lumber industry and woodworkers.^[5] It is highly figured with a rich brown color and striking grain patterns, especially in the crotch areas, where large limbs meet the trunk.^[6] It is used in small quantities to make fine furniture and gun stocks, and sold as slabs to make large natural-top tables because of its durability, good working properties and swirling, iridescent figure.

Some confusion exists about the nature of claro walnut because J. hindsii is commonly used as the rootstock of orchard trees. The section below the original graft is claro walnut wood, while the section above is the lighter-colored English walnut. Some woodworkers have even taken advantage of this by making the change in color of the wood a feature of their work.^[7]

References

• Hickman, James C., ed. The Jepson Manual: Higher Plants of California. University of California Press. 1993.
• Anderson, E. N. "Some preliminary observations on the California black walnut (Juglans californica)" in Fremontia: A Journal of the California Native Plant Society. January 2002.