Can someone please give me the name of the walnut variety which has husks that don't stain. There are several of these trees growing near our home in Oregon. The ripe nuts often fall right out of the green husks, and the shells are perfectly clean. The intact husks peel off easily by hand and there is absolutely no staining. I've searched on the web and in the Sunset Western Garden Book for a variety which fits this description but to no avail. These trees are about 80 years old, so they may be a variety which is no longer widely known or sold. If anyone can help me identify them, it will be much appreciated as I would like to buy some nursery stock to plant on my property.