A thin wooden rod or stick, historically used for striking students as punishment, or a plant (fennel) whose hollow stems were used to make such rods.
From Latin ferula (fennel plant). The Romans noticed that fennel stalks were hollow and lightweight, making them perfect for disciplinary rods used in schools.
The ferula is why we still say 'schoolmaster' and 'discipline'—for centuries, teachers carried these fennel-stalk rods as symbols of authority, and the plant's name became synonymous with harsh punishment.
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