A citron is a large, bumpy-skinned citrus fruit that looks like a lumpy, oversized lemon. Unlike lemons or oranges, citrons have very little juice and pulp inside. Instead, they're prized for their thick, fragrant rind, which people use to make candied peel, marmalade, or to add flavor to baked goods.

Citrons are one of the oldest citrus fruits, cultivated for thousands of years in Asia and the Mediterranean. In Jewish tradition, a special citron called an etrog plays an important role in the fall holiday of Sukkot. The fruit's thick peel releases a wonderful lemony fragrance, which is why perfume makers also value citron oil.

You might see candied citron in fruitcakes or holiday cookies: those little bright green or yellow pieces of sweetened fruit peel. While fresh citrons aren't common in grocery stores, their distinctive scent and flavor have made them valuable throughout history, even though you can't simply slice one open and eat it like an orange.