Alan Carruth wrote: ↑
Fri Jun 22, 2018 4:28 pm
California 'claro' walnut is, I believe, English walnut grafted to American black walnut roots. It can have some wild grain due to the graft.
"Claro walnut" is Juglans hindsii. Native to northern California, it is only called "claro" in the lumber industry. Most people here in California just call the trees "black walnut", or sometimes "Hinds' walnut", but it is a distinct species from eastern black walnut (Juglans nigra), and the wood is distinctive as well--red-brown and orange swirls, rather than the fairly uniform bittersweet chocolate tone of the eastern tree. It is
often used as rootstock in commercial walnut orchards--grafted to juglans regia ("English walnut"). Lumber cut across the graft line has a dramatic shift in heartwood color. Most claro walnut lumber comes from the abundant large mature Hind's walnut trees that grow along rivers in much of northern California.