Nuts

From Wikipedia: "A nut in botany is a simple dry fruit with one seed (rarely two) in which the ovary wall or part of it becomes very hard (stony or woody) at maturity."

Nuts that are (probably) period:

• Walnuts
• Almonds
• Chestnuts
• Acorns
• Pine nuts
• Filberts/hazelnuts
• Peanuts (barely - brought to Europe in 16th century as a curiosity)
• Pistachios (barely - Roman Empire/Middle Eastern)