By Harold McGee
The nuts (from an Indo-European root meaning “compressed”) come from several different plant families, not just one. They are generally large seeds enclosed in hard shells, and borne on long-lived trees. The seeds are large both to make them attractive to animal dispersers (which bury some for later use and effectively plant the ones they forget), and to give the seedling an adequate food supply for slow, prolonged growth in the partial shade. Most of them store their energy not in starch but in oil, a more compact, concentrated chemical form.