identifyingplants:

Carya glabra // Pignut

• Grows in rich, medium moisture, well-drained soils in full sun to part shade. Best performance occurs in moist soils. Generally intolerant of shade. Primarily native to hillsides and ridges. Zone 4-9.
• Native to the Eastern United States
• 50-80’.
• Leaves: Compound, odd-pinnate, dark yellowish-green.  Toothed, ovate-lanceolate leaflets to 3-6” long.
• Flowers: Yellowish-green. Male flowers in drooping catkins  and female flowers on short spikes. 
• Fruit: rounded nuts produced after the tree is 25 years old.
• Bark: Thick, deep ridges, grey.
• Difficult to transplant because of the deep taproot.

(Information from the Missouri Botanical Garden website.)