Question
There are lots of pignut hickory trees in the woods around my house.  This is a bad year for the nuts, but there are still a lot, because there are so many trees.  In the books that I have read, it says they are bitter and inedible, but sometimes sweet.  I'm not sure what this means.  Are these nuts edible or not?  

Answer
The true pignut hickory, Carya glabra the nuts are on the bitter side. Some times they are cross breed with bitternut hickory,  Carya cordiformis  and look similar. Some folks say if you let them dry out in a dry place they will lose the bitter taste. They are edible. Small nut with not much meat in them.