Walnuts and hickories are closely related, and I'm not yet sure I can reliably tell the bark apart. But on the east side of Laurel Brook Rd, there are black walnuts on the ground, and the bark of this tree can be flaked off to reveal a rich red-brown layer.

If you're patient (and willing to work with tools, and not too afraid of stains), the black walnut harvest, in the fall, is a treat. The shells are among the hardest vegetable substances in nature, and the fleshy husks (almost as big and almost as green as tennis balls) contain a powerful tannin. Given these two deterrents, the fact that squirrels still go after the nuts is a sign of how delicious they are. (For human consumption, though, the nuts do need cooking.)

Here’s a glimpse of the bottom of the trunk, with outer layers of bark worn away to reveal a subtle marbling: