I was at Cornell's McDaniel's Nut Grove today. The area was developed about 70 years ago by professor McDaniels as a place to test the growth and productivity of various grafted, mostly shagbark (C. ovata) hickory. The specimen below doesn't fit with anything I've seen or been able to locate. I created a hickory ID table and it is attached here. The table is based on the book by Don Leopold, as noted in the table header.
Anyone have any ideas on the correct species? Is anyone familiar with any Asian or European species of Carya? The key features are
I still have not found a conclusive diagnosis of this specimen. It may be pecan (C. illinoensis, also spelled illinoinensis). The description provided through the Texas A&M website suggests more variation in features than I originally suspected.
It could also be a Bitternut, which is closely related to Pecan but the nut is inedible and small. Dr. MacDaniels was experimenting with rootstocks compatibility for grafting selected varieties.