If you are the foraging sort, this is the season for black walnuts. I picked up the ones in the photo (and many more) along the side of my street in Asheville. The opposite side of our street is public right-of-way, as it falls down a sharp hill to the street below. There are several walnut trees, a couple of green apple trees, and a crabapple in the neighborhood right-of-ways - the produce of which is all free for the taking. Thank you, Asheville: City of Trees.
Black walnuts have a strong, distinctive flavor. If you haven't had them, they are not like English walnuts at all, at least to my taste. The first chore is removing the green husk. This is a pain, and the husk (which is used in some traditional dyes) will stain the beejeesus out of your hands and clothes. The best method I know is to put them in your driveway, and drive over them for a few days. Seriously. Once you are free of the husks, you have to break open the nuts, which (again) is none too easy. It can be done with a very sturdy nut-cracker, although a hammer comes in handy and is my weapon of choice. And then you will need a good nut-pick, as the nut-meats are not particularly easy to extract. Did I mention that black walnuts are so delicious that humans have been willing to put up with all this nonsense for centuries, to get at them?
Black walnuts are one of my mother's favorite foods, so we used to gather large quantities from my grandparents' farms. While not as passionate as my mother, I do enjoy them. They are wonderful in any chocolate concoction - chocolate chip cookies, cake, brownies, or fudge. Black walnut ice cream will bring all the boys (and girls) to the yard. And they are delicious in faux-chicken salad (made with tempeh, loosely following the recipe here) and vegetable stir-frys.
Black walnuts are very nutritious, but you'll eat them because they taste good! If you see these strange green globes along the roadside or in your yard, pick them up!