View photos of the edible plant Carya ovata (Shagbark hickory) profiled in the Wild Edible Series: Alabama, Arkansas, Kansas, Louisiana, Missouri, Oklahoma, Tennessee, and Texas: Vol 1.

A passage from Wild Edible Plants of Arkansas:

Place the de–hulled nuts in a bucket of water. Discard the
nuts that float (this usually means they’re insect damaged). Remove the submerged nuts and keep them in a dry place.

A passage from Wild Edible Plants of Kansas:

All species of Carya technically have edible nuts, BUT some species are better tasting than others. Shagbark
hickory (Carya ovata) is considered the best tasting;