I thought I had found all the nuts around here, but today I walked with my friend L, a great forager of wild foods, and she showed me (right hand page) a whole other layer of nuts that I wasn't even seeing, so intent was I on finding great numbers of lovely if inedible buckeyes. At the top in its light green dehiscent case is a hickory nut, and next to the slightly opening case is a hickory nut itself. Under the hickory nut is a butternut (which I had guessed was a hazel nut but which isn't). The clue to its butternutness is the lemon-shaped indehiscent case, which has a distinct citrusy smell. Skip to the bottom row and you will see a brown butternut case, which seems to be what happens when they ripen and start to disintegrate and develop lots of tannen. I pried the case off, no easy job, and found the nut inside, looking like a small walnut, which makes sense as it is a relative of the black walnut. This one has been gotten to by some worms and had mostly blackish powder where the nut meat was supposed to be.
The prickly green case above the butternuts is a cinquepin oak nut, a kind of acornish-looking nut that is really a relative of the chestnut. If you wait long enough, the case splits open and you find the glossy, tear-drop shaped cinquepin nut, prized for its sweet, chestnut-like meat. L taught me how to split it open with my teeth (not a problem as the skin is tough but flexible and won't chip your teeth) and get at the meat. Delicious!