Claro Walnut grows in Northern California and is commonly used as the root stock for English Walnut orchard trees.
Much of this wood is sustainably harvested and many guitar sets come out of old stumps.
A Claro tree can produce material that is exquisitely figured while displaying striations of red, purple, honey brown and even black color variations.
The density of Claro parallels Koa and is harder than most Honduras Mahogany.
I think of it primarily as a back & side material for fingerstyle playing and favor it for smaller bodied guitars.
Tonally, I expect from a Claro guitar, punctuation, clarity and exceptional note separation. Coupled with Adirondack or German Spruce this material can produce a brilliantly crisp treble with a vibrant midrange and a low end that projects rather than booms.