Short answers, pulled from the story.
The oldest fossils attributed to the genus Carya are Cretaceous pollen grains discovered in Mexico and New Mexico, proving that these trees have thrived on the continent for over 65 million years. Modern Carya first appear in Oligocene strata 34 million years ago. The Pleistocene Ice Age beginning 2 million years ago obliterated the genus from Europe.
The name hickory derives from a Native American word in an Algonquian language, perhaps Powhatan, serving as a linguistic bridge between the indigenous people and the natural world. It is a shortening of pockerchicory, pocohicora, or a similar word, which may be the name for the hickory tree's nut, or may be a milky drink made from such nuts. The genus name Carya comes from the Greek word meaning nut, reflecting the tree's most valuable product.
The Angiosperm Phylogeny Group considers the fruit to be a nut, despite the presence of an outer husk. The fruit is a globose or oval nut, 1 to 3 centimeters long and 1 to 2 centimeters in diameter, enclosed in a four-valved husk, which splits open at maturity. The nut shell is thick and bony in most species, but thin in a few, notably the pecan, which splits apart when the seed germinates.
Hickory wood is hard, stiff, dense, and shock resistant, a combination of properties not found in any other commercial wood. It is used in tool handles, bows, wheel spokes, walking sticks, drumsticks, and wood flooring. Hickory was also extensively used for the construction of early aircraft, a testament to its strength and durability.
The larvae of some Lepidoptera species, including the Luna moth, Brown-tail moth, and Regal moths, feed on hickory leaves. The caterpillars of the Regal moths are known as hickory horn-devils, a name that reflects their striking appearance and the tree's role in their life cycle. The banded hickory borer is another insect species found on hickories, contributing to the tree's ecological role.
Dried hickory nuts are 3% water, 18% carbohydrates, 13% protein, and 64% fats, making them a rich source of food energy and dietary minerals, especially manganese at 220% of the Daily Value. Hickory nuts were a significant food source for indigenous peoples of the Eastern Woodlands of North America since the middle Archaic period. They were used by the Cherokee in Kanuchi soup, but more often edible oil would be extracted through crushing the nuts and then either straining or boiling the remains.