A boll is the rounded seed pod that grows on cotton plants. After a cotton plant flowers, this protective capsule forms and swells up like a small green ball. Inside, cotton fibers grow around the seeds. When the boll ripens and dries out in late summer or fall, it splits open to reveal the fluffy white cotton we recognize.

Before cotton could be picked by machines, workers walked through fields plucking these bolls by hand, which was hot, exhausting work. The phrase “from boll to bolt” describes cotton's journey from the field to a bolt of fabric.

The boll weevil, a small beetle that eats cotton bolls, once devastated Southern cotton crops in the early 1900s. Farmers lost entire harvests when these insects destroyed their bolls before the cotton could be picked. This crisis forced many farmers to diversify their crops instead of relying entirely on cotton, which ultimately strengthened Southern agriculture.

You might also see boll used for the seed pods of flax plants, though it's most commonly associated with cotton.